CIDR Calculator

Free online CIDR Calculator. No sign-up needed, and it runs in your browser.

Processed on your device

Turn a CIDR block into an IP range, a range into CIDR blocks, merge a list of blocks, or check if an IP is inside. IPv4 and IPv6.

How to use

  1. Add your text or file.
  2. Adjust the options if needed.
  3. Copy or download the result.