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Subnet Calculator
Calculates network address, broadcast, usable host range, wildcard mask and host count from an IP and CIDR prefix.
Developer
Nothing uploaded
No sign-up
Free, unlimited
Enter your figures and press Calculate.
In short
Subnet Calculator is a free online tool on inputtesthub.com that calculates network address, broadcast, usable host range, wildcard mask and host count from an IP and CIDR prefix. It needs no account, no download and no payment, and there is no daily usage limit. Everything is processed inside your own browser, so the data you paste is never uploaded to a server.
How to use the Subnet Calculator
- Enter your figures in the input fields.
- The result updates as you type, together with the full working.
- Check the breakdown table to see exactly how the number was reached.
About the Subnet Calculator
The Subnet Calculator calculates network address, broadcast, usable host range, wildcard mask and host count from an IP and CIDR prefix. It runs as plain JavaScript inside the page, which means there is no upload step, no queue and no size limit imposed by a server — the only limit is your own device.
What people use it for
- Planning an IP allocation for a network.
- Working out whether two addresses are on the same subnet.
- Studying for a networking certification.
Frequently asked questions
Is the Subnet Calculator free?
It is free, with no account, no trial and no daily cap. Every developer tool on inputtesthub.com works the same way: open the page and use it.
Is my data uploaded anywhere?
No. The Subnet Calculator runs entirely in your browser using JavaScript. Because the work happens locally, the tool also keeps working if your connection drops, and closing the tab is all it takes to discard everything.
What do people use the Subnet Calculator for most?
The most common reasons people reach for it: planning an IP allocation for a network. Working out whether two addresses are on the same subnet. Studying for a networking certification. It is built for exactly those cases rather than being a general-purpose tool with this bolted on.
Is the number rounded?
The calculation runs in double precision and the result is shown to ten significant figures, so converting a value and converting it back returns the original. What is displayed is rounded for readability; what is copied is not.
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