Wire Gauge (AWG) Chart & Calculator

In short American Wire Gauge runs backwards from intuition: a SMALLER number means a THICKER wire, so AWG 10 is far heavier than AWG 20. The scale is logarithmic, and the useful rule is that every three gauges roughly doubles or halves the cross-sectional area — so AWG 14 at 2.08 mm² is about twice the copper of AWG 17 and half of AWG 11. AWG 14 itself is 1.628 mm in diameter. The two current columns differ enormously and both are correct for their purpose. Chassis wiring assumes a single wire in open air where heat escapes freely and allows a much higher current; power transmission wiring assumes a bundle inside a conduit where heat accumulates, and derates heavily as a result. Using the chassis figure for a wire in a loom is the classic way to melt insulation. Voltage drop is the other constraint people forget, and on long runs it usually decides the gauge before the current rating does — a wire that is thermally fine over 30 metres can still deliver too little voltage at the far end. This is a reference table for copper at 20 °C and is not a substitute for electrical code compliance.