IPv4, one range at a time.

Explore how a CIDR prefix divides a 32-bit address into a fixed network and a host range. Everything you type stays in this browser.

Normalized network
Broadcast / upper endpoint
Total addresses
First usable
Last usable

32-bit IPv4 diagram: a /24 prefix fixes the first 24 blue network bits; the final 8 amber host bits vary from 0 to 255.
A /24 example: three fixed octets and one variable octet. The selected prefix may differ.

A calculated usable range is not a promise that addresses are routable. Special-use ranges, local network policy and device configuration still apply.