FREE TOOL / DEVELOPER

IPv4 Subnet Calculator

Calculate an IPv4 network, subnet mask, address range, and usable hosts from a CIDR prefix.

Runs in your browser

IPv4 Subnet CalculatorYour input stays on this device

How to use this tool

Enter your information and choose any options.
Run the tool to see the result.
Copy the result if you need it elsewhere.

Good to know

For /31, the usable range follows point-to-point convention; /32 represents one address. Processing happens in your browser.