CIDR subnet calculator
Enter IPv4/prefix, such as 192.168.1.10/24, to calculate network, broadcast, mask and address counts.
Runs in this browser. Input stays on this device.
How to use
- Start with the supplied example. Adjust the input and select a mode if shown.
- Run the tool, inspect the result and copy when ready.
- Keep the units, format and destination requirements in mind.
Data & privacy
Calculation happens in this browser. Inputs are not sent to a calculation API. Copying uses your device clipboard.