CIDR / IP Converter

Calculate subnet ranges and host capacity from IPv4 CIDR notation.

Range details

About this tool

This CIDR calculator helps network and security teams quickly translate subnet notation into actionable range data, including first/last host addresses and usable host count.

Common use cases

  • Validate network segmentation plans.
  • Check firewall and ACL range assumptions.
  • Troubleshoot cloud/VPN subnet mismatches.

How it works

  1. Enter an IPv4 CIDR block.
  2. Click Calculate Range.
  3. Review network, mask, host span, and broadcast.

FAQ

Does this support IPv6?
No, this version focuses on IPv4 CIDR.

How are hosts calculated?
Usable hosts are derived from CIDR size minus network/broadcast where applicable.