Developer

IPv4 Subnet Calculator

Calculate network address, broadcast address, usable host range, subnet mask and host capacity from IPv4 CIDR notation.

✓ No signup✓ Mobile friendly✓ Clear limitations✓ Browser-first where practical
Recent tools are remembered only on this device.
Developer note. This uses conventional IPv4 subnet arithmetic. /31 and /32 are reported without subtracting network and broadcast addresses.

Why use this ipv4 subnet calculator?

Calculate network address, broadcast address, usable host range, subnet mask and host capacity from IPv4 CIDR notation. It is designed as a focused browser utility so you can test a scenario or transform data without creating an account.

Example

Paste a small representative sample into IPv4 Subnet Calculator, review the generated result, then copy it into your development or data workflow after checking the output.

Important note

Generated developer output should be reviewed before production use. Keep secrets, credentials and sensitive production data out of browser tools unless you control the environment and understand the risk.

How to use it

Start with the inputs shown above, review the assumptions or options, then generate the result. Where the tool creates a file, keep the original until you have opened and checked the downloaded output.

Frequently asked questions

Is IPv4 Subnet Calculator free?

Yes. The core tool is free to use without creating an account.

Do I need an account to use IPv4 Subnet Calculator?

No. You can use the core Toolbox workflow without signing up.

Does IPv4 Subnet Calculator work on mobile?

Yes. Toolbox is designed for modern mobile and desktop browsers, although complex file workflows can be easier on a larger screen.