How to Use the IP Subnet Calculator (CIDR)

2. How to use the IP Subnet Calculator (CIDR)

Here is the whole process, step by step. It takes less than a minute from opening the tool to seeing your result.

1. 1Fill in the IP address / CIDR, Or choose mask fields.
2. 2Your result appears on the page.

Your result updates as you type — there is nothing to press and nothing to wait for.

Everything runs in your browser — your files and text never leave your device.

3. Tips for best results

1. Your text never leaves your device — The tool runs entirely in your browser using JavaScript. Nothing is uploaded, so you can paste private documents without worry. That also means there is no account to create and no file to upload.
2. It works on your phone too — Open the tool in any modern browser on Android or iPhone. The layout adjusts to the screen and everything works the same way on a small screen as on a desktop.

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