001
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Loan Calculator
Works out the monthly payment, total interest and full repayment schedule for any loan from…
382 tools · free · no account
Calculators
Calculators that show the formula, not just the number. Loans, EMI, mortgages, tax, salary, BMI, calories, pregnancy, percentages, statistics, dates and business margins — each with a breakdown you can check.
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002
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EMI Calculator
Calculates your Equated Monthly Instalment with a full principal-versus-interest breakdown and…
003
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Mortgage Calculator
Estimates a full monthly housing payment including principal, interest, property tax…
004
Car Loan Calculator
Calculates a car finance payment from the price, deposit, trade-in, interest rate and term…
005
Personal Loan Calculator
Works out instalments and total cost for an unsecured personal loan, including any processing…
006
Amortization Schedule Calculator
Produces a complete month-by-month table showing how each payment splits between interest and…
007
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Compound Interest Calculator
Shows how savings grow with compound interest, including regular contributions and any…
008
Simple Interest Calculator
Calculates simple interest and the final amount from principal, rate and time, without…
009
SIP Calculator
Projects the maturity value of a monthly Systematic Investment Plan, showing invested amount…
010
Lumpsum Investment Calculator
Calculates what a one-off investment grows to at a given annual return over any number of years.
011
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ROI Calculator
Calculates return on investment as a percentage and in money terms, with an annualised figure…
012
CAGR Calculator
Calculates compound annual growth rate between a starting and ending value over any number of…
013
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Profit Margin Calculator
Calculates gross margin, markup, profit and the selling price you need to hit a target margin.
014
Markup Calculator
Works out selling price from cost and markup percentage, and converts between markup and margin.
015
Break-Even Calculator
Finds how many units you must sell to cover fixed costs, plus the break-even revenue and…
016
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Discount Calculator
Calculates the sale price and money saved from any discount, and can stack multiple discounts…
017
Sales Tax Calculator
Adds or removes sales tax at any rate and shows the net amount, tax amount and gross total…
018
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GST Calculator
Calculates GST at 5%, 12%, 18% and 28% or any custom rate, both adding it to a net price and…
019
VAT Calculator
Adds or removes VAT at 20%, 5% or any custom rate, showing the net, VAT and gross amounts…
020
Income Tax Slab Calculator
Calculates tax across progressive slabs you define, showing the amount in each band and the…
021
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Salary Calculator
Converts pay between hourly, daily, weekly, monthly and annual figures using your real working…
022
Freelance Hourly Rate Calculator
Works out the hourly rate you need to charge to reach a target income after costs, holidays…
023
Overtime Pay Calculator
Calculates total pay including overtime at time-and-a-half, double time or any custom…
024
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Tip Calculator
Works out the tip and total bill at any percentage, and splits it evenly between any number of…
025
Inflation Calculator
Shows what an amount of money is worth after inflation over any number of years, and what it…
026
Retirement Calculator
Projects your retirement pot from current savings, monthly contributions and expected returns…
027
Savings Goal Calculator
Works out how much to save each month to reach a target by a set date, or how long a fixed…
028
Credit Card Payoff Calculator
Shows how long a card balance takes to clear and the interest it costs, comparing minimum…
029
Debt-to-Income Ratio Calculator
Calculates your DTI ratio from monthly debt payments and gross income, and shows how lenders…
030
Net Worth Calculator
Adds up assets and subtracts liabilities to give your net worth, with a breakdown of what is…
031
Rent vs Buy Calculator
Compares the total cost of renting against buying over your planned time in the property…
032
Invoice Total Calculator
Adds line items, applies a discount, tax and shipping, and gives the final invoice total with…
033
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BMI Calculator
Calculates Body Mass Index from height and weight in metric or imperial units and shows the…
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BMR Calculator
Calculates Basal Metabolic Rate — the calories your body burns at complete rest — using the…
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TDEE Calculator
Estimates Total Daily Energy Expenditure from your BMR and activity level, with calorie…
036
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Calorie Calculator
Works out daily calories for losing, maintaining or gaining weight, with a projected timeline…
037
Macro Calculator
Splits your daily calories into protein, carbohydrate and fat grams for several common diet…
038
Body Fat Percentage Calculator
Estimates body fat percentage from tape measurements using the US Navy method, with fat mass…
039
Ideal Weight Calculator
Shows ideal body weight from four established formulas — Devine, Robinson, Miller and Hamwi —…
040
Water Intake Calculator
Estimates how much water to drink daily based on body weight, activity, climate and pregnancy…
041
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Pregnancy Due Date Calculator
Estimates the due date from your last period, conception date or IVF transfer, with a full…
042
Ovulation Calculator
Estimates your fertile window, ovulation day and next period date from your cycle length and…
043
Period Calculator
Predicts your next several period dates and cycle phases from your last period and average…
044
Heart Rate Zone Calculator
Calculates your five training heart rate zones from maximum or reserve heart rate, using the…
045
One Rep Max Calculator
Estimates your 1RM from a submaximal set using Epley, Brzycki and Lombardi formulas, with a…
046
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Running Pace Calculator
Converts between pace, speed, distance and finish time, with split times for common race…
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Calories Burned Calculator
Estimates calories burned in any activity from MET values, your body weight and the time spent.
048
Waist to Hip Ratio Calculator
Calculates waist-to-hip ratio and waist-to-height ratio and compares them against WHO health…
049
Lean Body Mass Calculator
Calculates lean body mass and fat mass using the Boer, James and Hume formulas.
050
Protein Intake Calculator
Works out daily protein needs from body weight, activity level and goal, in grams and as a…
051
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Sleep Cycle Calculator
Suggests bedtimes or wake times aligned to 90-minute sleep cycles so you wake between cycles…
052
Blood Alcohol Content Calculator
Estimates BAC from drinks, body weight, sex and time elapsed using the Widmark formula.
053
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Percentage Calculator
Solves every common percentage question in one place: X% of Y, X is what percent of Y, and…
054
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Percentage Increase Calculator
Calculates the percentage increase or decrease between two numbers, with the absolute…
055
Percentage Difference Calculator
Calculates the percentage difference between two values relative to their average — the…
056
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Fraction Calculator
Adds, subtracts, multiplies and divides fractions and mixed numbers, giving the answer fully…
057
Fraction to Decimal Converter
Converts any fraction or mixed number to a decimal, marking recurring digits, and converts…
058
Ratio Calculator
Simplifies ratios, scales them up or down, solves for a missing term and converts between…
059
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Average Calculator
Calculates the mean, median, mode, range and sum of any list of numbers, pasted in any format.
060
Mean Median Mode Calculator
Finds mean, median, mode, range, quartiles and outliers for a dataset, with a sorted view of…
061
Standard Deviation Calculator
Calculates population and sample standard deviation, variance, mean and standard error, with…
062
Variance Calculator
Calculates sample and population variance with the full deviation table so you can check every…
063
Probability Calculator
Calculates single and combined event probabilities — and, or, not, conditional — with results…
064
Permutation and Combination Calculator
Calculates nPr and nCr with and without repetition, and shows the factorial working behind…
065
Factorial Calculator
Calculates the factorial of any number up to very large values using exact big-integer…
066
GCD and LCM Calculator
Finds the greatest common divisor and lowest common multiple of two or more numbers, with the…
067
Prime Number Checker
Checks whether a number is prime, shows its factors if not, and lists the nearest primes above…
068
Square Root Calculator
Calculates square roots, cube roots and any nth root, giving both the exact simplified surd…
069
Exponent Calculator
Raises any number to any power, including negative and fractional exponents, with the working…
070
Logarithm Calculator
Calculates logarithms in any base, plus natural log and log base 10, and converts between bases.
071
Quadratic Equation Solver
Solves ax² + bx + c = 0 with the quadratic formula, showing the discriminant, both roots and…
072
Scientific Notation Converter
Converts between standard decimal notation, scientific notation, E notation and engineering…
073
Rounding Calculator
Rounds numbers to decimal places, significant figures or the nearest multiple, using several…
074
Triangle Calculator
Solves any triangle from three known values, giving all sides, angles, area, perimeter and the…
075
Circle Calculator
Calculates radius, diameter, circumference and area of a circle from any one known value.
076
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Area Calculator
Calculates the area of squares, rectangles, triangles, circles, trapezoids, ellipses…
077
Volume Calculator
Calculates the volume of cubes, boxes, cylinders, spheres, cones, pyramids and capsules in any…
078
Slope Calculator
Calculates slope, gradient, angle, distance and the line equation between two points.
079
Pythagorean Theorem Calculator
Finds the missing side of a right triangle from the other two, and checks whether three sides…
080
Weighted Average Calculator
Calculates a weighted mean from values and their weights, showing each item's contribution to…
081
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Age Calculator
Calculates exact age in years, months and days from a date of birth, plus total days, hours…
082
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Date Difference Calculator
Counts the days, weeks, months and years between two dates, with an option to count only…
083
Add or Subtract Days from a Date
Adds or subtracts days, weeks, months or years from any date and gives the resulting date and…
084
Business Days Calculator
Counts working days between two dates, excluding weekends and any public holidays you enter.
085
Time Duration Calculator
Adds and subtracts times and durations, and converts between hours, minutes and seconds.
086
Work Hours Calculator
Adds up a week of shifts with breaks and gives total hours, overtime and pay at your hourly…
087
Week Number Calculator
Finds the ISO week number for any date, and the date range covered by any week number in a…
088
Leap Year Checker
Checks whether any year is a leap year and lists the leap years before and after it.
089
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Days Until Calculator
Counts down to any future date in days, hours, minutes and seconds, live.
090
Birthday Countdown
Shows how many days until your next birthday, what age you will turn and which weekday it…
091
popular
GPA Calculator
Calculates grade point average from course grades and credit hours on a 4.0, 5.0 or 10-point…
092
CGPA Calculator
Calculates cumulative GPA across semesters and converts CGPA to a percentage.
093
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Grade Calculator
Works out your current grade from weighted assessments and what you need on what remains.
094
Final Exam Grade Calculator
Calculates the exact score you need on a final exam to reach your target grade for the course.
095
Percentage to CGPA Converter
Converts between percentage and CGPA using the standard conversion factor, in both directions.
096
Marks Percentage Calculator
Calculates exam percentage from marks obtained and total marks, across any number of subjects.
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Attendance Percentage Calculator
Calculates attendance percentage and tells you how many more classes you must attend to reach…
098
Test Score Calculator
Converts a raw score into a percentage and letter grade, with an option to apply a curve.
099
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Paint Calculator
Works out how many litres of paint a room needs from its dimensions, deducting doors and…
100
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Tile Calculator
Calculates how many tiles a floor or wall needs from the area and tile size, including a…
101
Flooring Calculator
Works out how many packs of flooring a room needs from its dimensions, the coverage per pack…
102
Roofing Calculator
Converts a building footprint and roof pitch into actual roof surface area and the number of…
103
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Concrete Calculator
Calculates the volume of concrete a slab, path or footing needs in cubic metres and cubic…
104
Cement Calculator
Splits a concrete or mortar volume into cement bags, sand and aggregate for a chosen mix…
105
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Brick Calculator
Calculates how many bricks a wall needs from its area, the brick size and the mortar joint…
106
Wallpaper Calculator
Works out how many rolls of wallpaper a room needs, accounting for the pattern repeat that is…
107
popular
Solar Panel Calculator
Sizes a solar array from your monthly electricity use, local peak sun hours and panel rating…
108
Water Tank Size Calculator
Works out the water tank capacity a household needs from the number of people, daily use per…
109
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AC Size Calculator
Recommends an air conditioner size in tons and BTU from room area, sun exposure, occupants…
110
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Electricity Bill Calculator
Calculates what an appliance costs to run per day, month and year from its wattage, hours of…
111
Generator Size Calculator
Sizes a generator in kVA from your total running watts and starting surge, applying headroom…
112
Pipe Size Calculator
Calculates the minimum pipe diameter for a required flow rate at a chosen water velocity, and…
113
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Steel Weight Calculator
Calculates the weight of steel bar, square section or flat plate from its dimensions, with the…
114
Sand Calculator
Calculates how much sand an area needs by volume and weight, with bag counts and an adjustable…
115
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Gravel Calculator
Works out the gravel needed to cover an area to a given depth, in cubic metres, tonnes and…
116
Asphalt Calculator
Calculates the tonnage of asphalt needed for an area at a given compacted depth, including the…
117
Screw Size Calculator
Recommends a screw length and gauge for the thickness you are fixing, with pilot and clearance…
118
Drill Bit Size Calculator
Gives the tap drill and clearance drill size for metric threads from M3 to M16, with pitch and…
119
Fuse Size Calculator
Converts an appliance wattage into the current it draws and recommends the next standard fuse…
120
Extension Cord Calculator
Works out the conductor size an extension lead needs for a given load and length, and shows…
121
Beam Load Calculator
Calculates support reactions, maximum shear and maximum bending moment for a simply supported…
122
Scaffolding Calculator
Estimates the bays, lifts, standards, ledgers, transoms and boards needed for a run of…
123
Nail Length Calculator
Recommends a nail length for the thickness being fixed using the three-times rule, and shows…
124
Bolt Thread Identifier
Identifies the closest metric thread from a caliper measurement, with pitch, spanner size and…
125
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PSU Calculator
Estimates the power supply wattage a PC build needs from its CPU, graphics card, drives and…
126
CPU Bottleneck Calculator
Compares relative CPU and GPU performance scores and estimates which part limits the other at…
127
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Battery Life Calculator
Calculates how long a battery will run a device from its capacity in mAh and the average…
128
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UPS Runtime Calculator
Calculates how long a UPS or battery bank will carry a load, accounting for depth of discharge…
129
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Power Bank Calculator
Works out how many full phone charges a power bank actually delivers, accounting for the…
130
Inverter Battery Runtime Calculator
Calculates backup time from an inverter battery bank for a given load, plus the current drawn…
131
Solar Battery Calculator
Sizes an off-grid battery bank in Ah from daily energy use, days of autonomy and battery…
132
AA & AAA Battery Life Calculator
Estimates how long AA, AAA, C, D or 9V cells will run a device from its average current draw.
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Monitor Size Calculator
Converts a screen diagonal and aspect ratio into actual width and height, with pixel density…
134
Charger Wattage Calculator
Converts a charger’s voltage and current into watts, matches it to the nearest USB-PD tier and…
135
Battery Charge Time Calculator
Calculates how long a battery takes to charge from its capacity, current state of charge and…
136
DC Voltage Drop Calculator
Works out the cable size a low-voltage DC run needs to stay within a voltage drop limit, and…
137
popular
Dog Age Calculator
Converts a dog’s age into human years using a size-adjusted scale, with life stage and typical…
138
Cat Age Calculator
Converts a cat’s age into human years, with life stage, typical lifespan and how often…
139
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Dog Food Calculator
Calculates a dog’s daily calorie requirement from body weight and life stage, converted to…
140
Pet Ideal Weight Calculator
Estimates a dog or cat’s ideal weight from its current weight and body condition score, with a…
141
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Aquarium Volume Calculator
Calculates a tank’s actual water volume after substrate and fill level, plus its filled…
142
Aquarium Water Change Calculator
Calculates how much water a change removes, the dechlorinator dose for it, and how far four…
143
Fertilizer Calculator
Works out how much fertiliser product an area needs from the target nitrogen rate and the…
144
Grass Seed Calculator
Calculates how much grass seed an area needs at the correct sowing rate for a new lawn…
145
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Coffee Ratio Calculator
Calculates coffee and water amounts for filter, French press, AeroPress, espresso or cold…
146
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Air Fryer Converter
Converts an oven temperature and time into air fryer settings, applying the standard 20°C and…
147
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Rice Water Calculator
Gives the water quantity and simmer time for white, basmati, jasmine, brown, wild or sushi…
148
Tea Brewing Calculator
Gives the leaf quantity, water temperature and steeping time for black, green, white, oolong…
149
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Road Trip Cost Calculator
Adds up the full cost of a road trip from distance, fuel consumption, tolls, accommodation and…
150
Fuel Split Calculator
Splits a fuel bill between passengers, with the option to exempt the driver who is supplying…
151
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Luggage Size Calculator
Checks a bag’s dimensions and weight against typical cabin and checked baggage allowances…
152
Flight Carbon Calculator
Estimates a flight’s CO₂e per passenger from distance and cabin class, including the altitude…
153
Time Zone Planner
Converts a time between two UTC offsets and shows the overlapping working hours for scheduling…
154
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Tire Size Calculator
Compares two tyre sizes for overall diameter, sidewall height, ground clearance and…
155
Wheel Offset Calculator
Compares two wheel width and offset combinations and shows how far each edge moves inward or…
156
Mileage Cost Calculator
Calculates fuel cost per kilometre and the true annual running cost once insurance, tax…
157
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EV Charging Cost Calculator
Calculates the cost and time to charge an electric car between two states of charge, including…
158
popular
Shipping Box Calculator
Calculates a parcel’s volumetric weight and shows which figure a carrier will charge, actual…
159
Parcel Weight Calculator
Adds up a parcel’s total shipping weight from contents, padding and the empty box, and checks…
160
Customs Duty Calculator
Estimates duty, import tax and total landed cost on an imported item, including the de minimis…
161
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Split Bill Calculator
Splits a restaurant bill between people, adding tax and a tip calculated on either the pre-tax…
162
Tax Bracket Calculator
Calculates tax across any set of progressive bands you enter, showing tax per band, effective…
163
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Pay Raise Calculator
Calculates a raise as a percentage and an amount, and shows what it is really worth once…
164
Subscription Cost Calculator
Adds up all your subscriptions on a common monthly basis, ranks them by cost and shows the…
165
Weighted GPA Calculator
Calculates weighted and unweighted GPA from a course list, applying the usual honors and AP or…
166
Emergency Fund Calculator
Works out how large an emergency fund should be from essential monthly expenses, and how long…
167
Cost Per Use Calculator
Calculates what an item really costs each time you use it, including running costs and resale…
168
Hourly to Salary Calculator
Converts an hourly rate into daily, weekly, monthly and annual figures, accounting for unpaid…
169
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Time Card Calculator
Adds up hours worked from daily start and end times with breaks, handling overnight shifts…
170
Study Time Calculator
Compares the study hours a syllabus needs against the time you have planned, and shows the…
171
Exam Countdown Calculator
Splits the days before an exam into learning and revision, and works out how many topics a day…
172
Class Average Calculator
Calculates mean, median, standard deviation, pass rate and grade distribution from a list of…
173
popular
Curtain Size Calculator
Works out curtain panel width and drop from the window size, rail overhang and the fullness…
174
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Wall Hanging Height Calculator
Calculates exactly where to mark the hook so artwork, mirrors or a television hang at the…
175
Ceiling Fan Size Calculator
Recommends a ceiling fan blade span from room area, and checks the down-rod and blade height…
176
Mattress Size Calculator
Compares every standard mattress size in centimetres and inches, and checks the clearance left…
177
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Will It Fit Calculator
Checks whether furniture will pass through a doorway, straight or tilted, using the diagonal…
178
TV Stand Size Calculator
Works out the stand width a television needs, the screen’s real width, and a comfortable…
179
Dining Table Size Calculator
Sizes a rectangular or round dining table for a number of seats, and the minimum room it needs…
180
Wardrobe Size Calculator
Calculates how much hanging rail, shelving and shoe space a wardrobe needs from what you…
181
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Room Lighting Calculator
Calculates the total lumens a room needs for its purpose, and how many bulbs of a given output…
182
Home Noise Calculator
Adds decibel levels correctly on a logarithmic scale to give the combined noise from several…
183
Freezer Capacity Calculator
Works out the freezer capacity a household needs from its size and how it shops, with running…
184
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Gas Cylinder Calculator
Estimates how many days an LPG cylinder will last from its size, the number of burners and…
185
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VO2 Max Calculator
Estimates VO₂ max from a 12-minute run, a 1-mile walk test or resting heart rate, with the…
186
Swim Pace Calculator
Converts a swim distance and time into pace per 100 m and 50 m, speed, time per length and…
187
Cycling Power Calculator
Calculates the power needed to hold a speed on a given gradient, split into air, rolling and…
188
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Steps to Distance Calculator
Converts a step count into distance using stride length derived from your height and pace…
189
Tape Body Fat Calculator
Estimates body fat percentage from neck, waist and hip measurements using the US Navy…
190
popular
Race Time Predictor
Predicts race times at every common distance from one known result using Riegel’s formula…
191
Creatine Dose Calculator
Calculates creatine loading and maintenance doses from body weight, with time to saturation…
192
Sweat Rate Calculator
Calculates your hourly sweat rate from weight lost during a session and shows how much to…
193
Sleep Debt Calculator
Adds up how far a week of sleep fell short of your target and how much extra per night would…
194
Walking Calories Calculator
Calculates calories burned walking from weight, speed, duration and incline using the ACSM…
195
Stair Climbing Calculator
Converts a number of stairs climbed into height gained, floors and calories burned, including…
196
Waist to Height Ratio Calculator
Calculates waist-to-height ratio, the screening measure that works across heights and…
197
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Marketplace Fee Calculator
Works out what you actually keep after marketplace commission, payment processing and…
198
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eBay Fee Calculator
Calculates eBay final value fees on the item and the shipping, then shows your payout, profit…
199
Etsy Fee Calculator
Adds Etsy listing, transaction and payment processing fees together to show your payout, the…
200
popular
Amazon FBA Calculator
Estimates Amazon referral, FBA fulfilment and storage fees per unit, then gives profit…
201
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Discount Stacking Calculator
Applies several discounts, coupons and cashback in order, shows the real single-discount…
202
Wholesale Price Calculator
Turns unit cost into a wholesale price at your target margin, then a retail price, showing…
203
Return Cost Calculator
Adds up shipping both ways, handling, unrefunded fees and lost stock value to show what one…
204
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Break-Even ROAS Calculator
Finds the ROAS, ACOS and cost per sale at which advertising breaks even for your margin, and…
205
Customer Lifetime Value Calculator
Calculates customer lifetime value from order value, purchase frequency, margin and retention…
206
Free Shipping Threshold Calculator
Finds the lowest free-shipping threshold that can pay for itself, then compares profit per…
207
Inventory Turnover Calculator
Calculates inventory turnover, days of stock on hand, weeks of cover, sell-through rate and…
208
Reorder Point Calculator
Calculates the reorder point and safety stock for your service level, plus the economic order…
209
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Water Usage Calculator
Works out how much water your household uses each day fixture by fixture, what it costs a…
210
Water Leak Cost Calculator
Shows how many litres and how much money a dripping tap or running toilet wastes, including…
211
popular
Shower Cost Calculator
Costs a single shower in water and heating energy, then compares a shorter shower, a low-flow…
212
Water Heater Cost Calculator
Calculates what heating your hot water costs a month, separates the standing loss from the…
213
Rainwater Harvesting Calculator
Works out how much rainwater a roof can collect a year from its area and rainfall, and what…
214
Pool Volume Calculator
Calculates swimming pool volume from its shape and average depth, then the fill time, fill…
215
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Child Height Predictor
Predicts a child's adult height from both parents' heights using the mid-parental method, with…
216
Baby Formula Calculator
Estimates how much formula a baby needs each day from weight and age, the amount per feed, and…
217
Nappy Cost Calculator
Adds up how many nappies a baby needs from now to potty training, what they cost with wipes…
218
Childcare Cost Calculator
Compares nursery, childminder and nanny costs a year, then sets them against the take-home pay…
219
Pocket Money Calculator
Sets a weekly allowance from a child's age, splits it into save, give and spend, and shows how…
220
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Baby Sleep Schedule Calculator
Builds a nap and bedtime schedule from your baby's age using wake windows, and checks the…
221
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Prayer Time Calculator
Calculates the five prayer times for any coordinates and date, with twelve calculation methods…
222
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Qibla Direction Calculator
Calculates the great-circle bearing to the Kaaba from any coordinates, with the compass point…
223
popular
Zakat Calculator
Works out zakat at 2.5% from your assets and debts, against either the gold or the silver…
224
Room CFM Calculator
Works out the airflow a room needs in CFM two independent ways — by air changes per hour and…
225
Duct Size Calculator
Sizes round and rectangular HVAC duct from airflow and target velocity, giving the friction…
226
Drywall Calculator
Works out how many drywall sheets a room needs, plus screws, joint tape and compound, from the…
227
Fence Calculator
Calculates fence posts, sections, rails, pickets and the concrete each post hole takes, from…
228
Insulation R-Value Calculator
Adds up an assembly R-value then corrects it for the studs, giving the whole-wall R and…
229
Job Quote Calculator
Builds a job price from materials, waste, labour, overhead and contingency, then shows the…
230
Pesticide Dilution Calculator
Works out how much concentrate and water go in a sprayer for a given ratio, percentage or rate…
231
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AC Running Cost Calculator
Works out what an air conditioner costs to run from its tonnage and star or SEER rating, and…
232
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Resistor Colour Code Calculator
Reads resistor colour bands into a value and tolerance, and tells you whether the result is a…
233
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Ohm's Law Calculator
Enter any two of voltage, current, resistance and power and get the other two, with the…
234
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LED Resistor Calculator
Works out the series resistor an LED needs, rounds it to a real E24 value and shows the…
235
Voltage Divider Calculator
Calculates a two-resistor divider output, the standing current, and how far the output sags…
236
Capacitor Code Calculator
Decodes three-digit ceramic capacitor markings into picofarads, nanofarads and microfarads…
237
RC Time Constant Calculator
Calculates the RC time constant, the charge and discharge curve at each step, and the filter…
238
Series and Parallel Resistor Calculator
Combines any list of resistors in series and in parallel, with the nearest standard value for…
239
Preferred Value Finder
Finds the nearest standard resistor value in every E series and shows how far off it is.
240
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Note Frequency Calculator
Converts any musical note to its frequency in hertz and any frequency back to the nearest…
241
MIDI Note Number Converter
Converts a MIDI note number to its note name and frequency, and back, across the full 0 to 127…
242
Musical Interval Calculator
Names the interval between two notes and shows how far equal temperament sits from the pure…
243
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Scale and Chord Builder
Builds any scale or chord from a root note, listing every note with its frequency and interval…
244
Transpose Calculator
Transposes a list of notes up or down by any number of semitones, with the frequency change…
245
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Tempo Delay Time Calculator
Turns a tempo into delay and reverb times in milliseconds for every note value, straight…
246
Frequency to Wavelength Calculator
Converts frequency to wavelength in air at any temperature, with the half and quarter…
247
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Molar Mass Calculator
Works out the molar mass of any chemical formula and breaks it down element by element, with…
248
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Chemical Equation Balancer
Balances any chemical equation in exact whole numbers and re-sums every element and the charge…
249
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Molarity Calculator
Solves for concentration, mass or volume of a solution from the other two, taking the molar…
250
Solution Dilution Calculator
Works out how much stock solution and how much diluent to use for any dilution, using C1V1 =…
251
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pH Calculator
Converts between pH, pOH, hydrogen and hydroxide concentration, and calculates the pH of…
252
Ideal Gas Law Calculator
Solves PV = nRT for pressure, volume, moles or temperature in the units you actually use, with…
253
Half-Life Calculator
Calculates how much of a radioactive sample is left after any time, or how long a given decay…
254
Percent Yield Calculator
Calculates percent yield from actual and theoretical yield, and works out the theoretical…
255
Empirical Formula Calculator
Turns percent composition or element masses into the empirical formula, and into the molecular…
256
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Sunrise Sunset Calculator
Calculates sunrise, sunset, solar noon and day length for any latitude, longitude and date…
257
Twilight Times Calculator
Gives the civil, nautical and astronomical twilight times for any place and date, and says…
258
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Golden Hour Calculator
Gives the golden hour and blue hour windows at both ends of the day for any place and date…
259
Day Length Calculator
Shows how daylight changes across a whole year at any latitude, finds the longest and shortest…
260
Sun Position Calculator
Gives the sun altitude and azimuth at any instant from any place, with the refraction…
261
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Moon Phase Calculator
Gives the moon phase, illuminated percentage and age for any date, plus the exact instants of…
262
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Next Full Moon Calculator
Finds the next full moon from any date, with the exact instant, and lists the following…
263
Julian Day Converter
Converts any calendar date to its Julian Day number and back, handling the Gregorian reform…
264
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Equinox and Solstice Calculator
Gives the exact instant of both equinoxes and both solstices for any year from 2000 to 2999…
265
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Depth of Field Calculator
Works out the near and far limits of sharpness for any sensor, focal length, aperture and…
266
Hyperfocal Distance Calculator
Finds the focus distance that puts everything from half that distance to infinity in…
267
Field of View Calculator
Calculates the horizontal, vertical and diagonal angle of view for any lens and sensor, and…
268
Crop Factor Calculator
Converts a focal length and aperture between any two sensor sizes, showing the equivalent…
269
Exposure Value Calculator
Calculates exposure value from aperture, shutter and ISO, and lists every equivalent exposure…
270
ND Filter Calculator
Works out the shutter speed you need with any neutral density filter, from ND2 to a solar…
271
Star Trail Calculator
Finds the longest exposure before stars trail, comparing the 500 rule with the NPF rule that…
272
Time-Lapse Calculator
Works out any one of the shooting interval, the finished clip length or the frames needed…
273
Flash Guide Number Calculator
Works out the aperture, distance or guide number for a flash at full power, with the ISO…
274
Z-Score Calculator
Turns a value into a z-score and a percentile, showing how far it sits from the mean in…
275
Normal Distribution Calculator
Finds the probability that a normal variable falls below, above, between or outside any two…
276
Confidence Interval Calculator
Builds a confidence interval for a mean from your sample mean, standard deviation and sample…
277
Margin of Error Calculator
Calculates the margin of error for a survey percentage at any confidence level and sample…
278
Sample Size Calculator
Works out how many survey responses you need for a target margin of error at any confidence…
279
P-Value Calculator
Converts a z, t or chi-square statistic into a p-value, one or two-tailed, with the critical…
280
T-Test Calculator
Runs a one-sample, paired or Welch two-sample t-test on your data, with the t statistic…
281
Chi-Square Calculator
Runs a chi-square goodness-of-fit or independence test on your counts, with expected values…
282
Correlation Coefficient Calculator
Calculates Pearson r and Spearman rho for paired data, with r squared, the significance test…
283
Linear Regression Calculator
Fits a least-squares line to paired data and gives the slope, intercept, r squared, standard…
284
Projectile Motion Calculator
Calculates the range, maximum height, flight time and impact speed of a projectile from its…
285
Free Fall Calculator
Works out how long an object takes to fall, and how fast it is going when it lands, from…
286
Terminal Velocity Calculator
Calculates the terminal velocity of a falling object from its mass, drag coefficient and area…
287
Pendulum Calculator
Calculates the period of a pendulum exactly, including the amplitude correction the usual…
288
Spring Constant Calculator
Calculates a spring constant from force and displacement using Hooke's law, with the stored…
289
Momentum Calculator
Calculates momentum and kinetic energy from mass and velocity, and the force needed to stop it…
290
Elastic Collision Calculator
Calculates the velocities after a one-dimensional collision, elastic and perfectly inelastic…
291
Escape Velocity Calculator
Calculates escape velocity and orbital velocity for any planet or moon, or for a body of your…
292
Centripetal Force Calculator
Calculates the centripetal force and acceleration needed to keep an object moving in a circle…
293
Kinetic Energy Calculator
Calculates kinetic energy from mass and speed, with the potential energy at a height and the…
294
Bayes Theorem Calculator
Works out what a positive test result actually means, from the base rate, sensitivity and…
295
Dice Probability Calculator
Calculates the probability of any total on any number of dice, with the complete distribution…
296
Lottery Odds Calculator
Calculates the odds of winning any lottery from the pool size and how many numbers are drawn…
297
Poker Hand Odds Calculator
The probability of every five-card poker hand, counted from first principles, with the number…
298
Expected Value Calculator
Calculates the expected value and standard deviation of any set of outcomes and probabilities…
299
Birthday Paradox Calculator
Calculates the chance that two people in a group share a birthday, for any group size and any…
300
Binomial Distribution Calculator
Calculates the exact probability of a number of successes in a fixed number of trials, with…
301
Poisson Distribution Calculator
Calculates the probability of a number of events in a period from the average rate, with the…
302
Odds to Probability Converter
Converts between decimal, fractional and American odds and implied probability, with every…
303
Card Probability Calculator
Calculates the chance of drawing a given number of matching cards from a deck, and shows how…
304
ANOVA Calculator
Runs a one-way ANOVA on any number of groups, with the F statistic, p-value, full…
305
F-Test Calculator
Compares the variances of two samples with an F test, showing the ratio, degrees of freedom…
306
Mann-Whitney U Test Calculator
Runs the Mann-Whitney U test on two independent groups, with U, the z approximation, the…
307
Wilcoxon Signed-Rank Test Calculator
Runs the Wilcoxon signed-rank test on paired data, with W, the rank sums, the z approximation…
308
Kruskal-Wallis Test Calculator
Runs the Kruskal-Wallis H test on any number of groups, with the tie correction, degrees of…
309
Levene's Test Calculator
Tests whether several groups have equal variances using Levene's test with the robust median…
310
Effect Size Calculator
Calculates Cohen's d and Hedges' g from two samples, and converts between d, r and eta squared…
311
Proportion Test Calculator
Runs a one or two-proportion z-test with the pooled standard error, the p-value and a…
312
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Knitting Gauge Calculator
Turns your swatch into a cast-on count and a row count for the size you want, in centimetres…
313
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Knitting Increase and Decrease Calculator
Works out how to space increases or decreases evenly across a row and writes the instruction…
314
Yarn Yardage Calculator
Estimates the yarn a project needs by scaling up a swatch you have knitted, with a margin for…
315
Knitting Needle Size Converter
Converts knitting needle sizes between metric, US and UK scales, and explains why the two…
316
Crochet Hook Size Converter
Converts crochet hook sizes between metric, US letter-number and UK scales, and flags where…
317
Fabric Yardage Calculator
Works out how much fabric to buy for a set of pieces, with seam allowances, fabric width and…
318
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Filament Length to Weight Calculator
Converts 3D printing filament between length, weight and volume for any diameter and material…
319
Filament Remaining Calculator
Works out how much filament is left on a part-used spool from its weight, and converts that to…
320
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3D Print Cost Calculator
Calculates what a 3D print costs in filament and electricity, with an optional allowance for…
321
Layer Height Calculator
Works out which layer heights land on a whole motor step for your Z axis, and what your nozzle…
322
Steps per mm Calculator
Calculates steps per millimetre for belt and lead-screw axes, and works out new E steps from…
323
3D Print Shrinkage Calculator
Works out the scale factor to compensate for shrinkage from the size you wanted and the size…
324
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Bike Gear Ratio Calculator
Converts a chainring and sprocket into gear ratio, gear inches, development and gain ratio for…
325
Bike Gear Chart
Builds the full gear chart for any chainring and cassette combination, and searches it for…
326
Bike Speed and Cadence Calculator
Converts between speed and cadence for any gear and wheel size, in both directions.
327
Bicycle Tyre Size Converter
Converts bicycle ETRTO tyre sizes to overall diameter and circumference, and shows which inch…
328
Spoke Length Calculator
Calculates bicycle spoke length from rim ERD, hub flange diameter, flange offset, spoke count…
329
Bike Chain Length Calculator
Works out bicycle chain length in links from chainstay length, largest chainring and largest…
330
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Board Foot Calculator
Works out board feet from thickness, width and length, with quarters notation and a cost per…
331
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Lumber Size Chart
Shows what nominal lumber sizes actually measure, and finds where the planing allowance changes.
332
Cut List Calculator
Works out how many boards a cut list needs, counting the saw kerf on every cut, and shows what…
333
Plywood Sheet Calculator
Works out how many sheets of plywood or MDF a set of parts needs, trying both orientations and…
334
Wood Shrinkage Calculator
Calculates how much a board shrinks or swells with moisture content, tangentially and…
335
Dovetail Layout Calculator
Works out where every tail and pin falls across a board, with half-pins at the ends and…
336
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Baker's Percentage Calculator
Converts a bread recipe between baker's percentages and weights, in both directions, with the…
337
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Dough Hydration Calculator
Calculates dough hydration and total hydration separately, counting the flour and water inside…
338
Sourdough Starter Calculator
Works out starter feeding by ratio, in both directions, with the hydration the fed starter…
339
Yeast Conversion Calculator
Converts between fresh, active dry and instant yeast, with the caveats that make the ratios…
340
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Pizza Dough Calculator
Works out pizza dough ball weights from pan size using thickness factor, for round and…
341
Dough Temperature Calculator
Works out the water temperature needed to hit a target dough temperature, with or without a…
342
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Raised Bed Soil Calculator
Works out the soil a raised bed needs in cubic feet, cubic yards, litres and bags, and splits…
343
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Mulch Calculator
Works out how much mulch a bed, circle or tree ring needs, in cubic yards, cubic feet, litres…
344
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Plant Spacing Calculator
Counts how many plants fit a bed at a given spacing, and compares square rows against offset…
345
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Compost Ratio Calculator
Works out the carbon to nitrogen ratio of a compost mix, or solves for the browns needed to…
346
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Seed Starting Calculator
Turns your last frost date into sowing, planting-out and harvest dates for 21 crops. No frost…
347
Seed Germination Calculator
Scores a germination test and works out seeds to sow, seeds per cell and the odds of a cell…
348
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Coffee Extraction Calculator
Works out extraction yield from dose, TDS and brew weight, and shows where a brew sits on the…
349
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Coffee Grind Size Chart
Converts grind size between microns, grinder clicks and brew method, for ten brewing methods…
350
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Caffeine Calculator
Adds up the caffeine in a day of coffee, tea and energy drinks and works out how much is still…
351
Coffee Roast Loss Calculator
Works out roast loss between green and roasted weight in either direction, with the real cost…
352
Cold Brew Calculator
Works out cold brew concentrate from a coffee dose, then the exact water needed to dilute it…
353
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Espresso Shot Calculator
Works out espresso brew ratio and flow rate from dose, yield and time, and the yield any…
354
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ABV Calculator
Works out alcohol by volume from original and final gravity by three published methods, with…
355
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Brix to Specific Gravity Converter
Converts between Brix, Plato, specific gravity and gravity points, with the wort correction…
356
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IBU Calculator
Works out IBU from hop additions using the Tinseth formula, with utilisation, the bitterness…
357
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Priming Sugar Calculator
Works out priming sugar for bottling from batch size, target carbonation and temperature, for…
358
Mash Water Calculator
Works out strike water temperature from a heat balance, plus mash, sparge and total water for…
359
Brewhouse Efficiency Calculator
Works out brewhouse efficiency from grain, volume and gravity, or the grain a target gravity…
360
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Clay Shrinkage Calculator
Works out clay shrinkage from a test bar, the volume it costs you, and how big to throw for a…
361
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Glaze Recipe Calculator
Batches a glaze recipe to any weight, with colourants handled as additions rather than shares…
362
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Pyrometric Cone Chart
Converts pyrometric cone numbers to temperature in Celsius and Fahrenheit, and back, for cones…
363
Kiln Firing Schedule Calculator
Adds up a kiln firing schedule from ramp rates, target temperatures and holds, with the…
364
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Kiln Firing Cost Calculator
Works out the electricity a kiln firing uses and what it costs, allowing for the fact that…
365
Clay Weight Calculator
Works out how much clay a cylindrical pot needs from its dimensions and wall thickness, with…
366
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Rebar Spacing Calculator
Counts the bars in a reinforcement mat from the slab size, spacing and cover, with laps…
367
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Water Cement Ratio Calculator
Works out the water to add at the mixer for a target water/cement ratio, counting the free…
368
Concrete Mix Ratio by Weight Calculator
Converts a volumetric concrete mix such as 1:2:4 into a weigh-batch in kilograms, using the…
369
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Block Wall Calculator
Counts concrete blocks for a wall, derives the mortar by subtraction, and works out the grout…
370
Formwork Area Calculator
Works out the formwork contact area and plywood sheet count for a slab, beam, column or wall…
371
Concrete Bags vs Ready-Mix Calculator
Compares the cost of bagged concrete against a ready-mix delivery for your volume, and solves…
372
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Candle Wax Calculator
Works out how much wax a container needs by weight from its volume, with the water-test…
373
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Fragrance Load Calculator
Splits a candle into wax and fragrance oil at any load percentage, working forward from the…
374
Candle Burn Time Calculator
Works out how long a candle burns from its wax weight and burn rate, using a typical rate or…
375
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Candle Wick Size Chart
Suggests a starting wick size by container diameter across the CD, ECO, LX and HTP series…
376
Candle Cost Calculator
Adds up the materials cost of a candle across wax, fragrance, wick, container and extras, with…
377
Wax Melt Calculator
Works out how many clamshell cavities and full packs a batch of wax makes, with the fragrance…
378
Return Deadline Calculator (UK & EU)
Works out the last day to cancel an online order, reject a faulty item or claim under the…
379
Christmas Shipping Deadline Countdown
Counts down the days to the USPS, Royal Mail and Parcelforce last posting dates for delivery…
380
Fake Discount Checker (EU 30-Day Price Rule)
Checks whether a sale discount is real by measuring it against the lowest price of the…
381
UK Energy Bill Calculator (Price Cap)
Estimates a yearly and monthly UK gas and electricity bill from your kWh at the Ofgem price…
382
Heat Pump vs Gas Boiler Running Cost Calculator
Compares the yearly running cost of a heat pump against a gas boiler from your gas use, boiler…
About these calculators
Calculators that show the formula, not just the number. Loans, EMI, mortgages, tax, salary, BMI, calories, pregnancy, percentages, statistics, dates and business margins — each with a breakdown you can check.
All 382 tools here are free and open immediately — there is no registration step, no credit card and no daily allowance to run out of. Most of them do their work in your browser, which means the page keeps working on a slow connection and your input is never sent to a server.