Subnet / CIDR Calculator
Calculate network address, broadcast address, subnet mask, and usable host range from CIDR notation, entirely in your browser.
How to Calculate an IPv4 Subnet for Free
1. Enter an IP address with its CIDR prefix, e.g. 192.168.1.0/24.
2. The network and broadcast addresses are calculated instantly.
3. The subnet mask, wildcard mask, and usable host range are shown below that.
4. Total and usable host counts update live as you change the prefix.
Calculation in Your Browser
Every calculation runs entirely in your browser using plain integer arithmetic — no network address is looked up or queried anywhere, so this is safe to use with real internal IP ranges.