Network utility

IPv4 CIDR Calculator

Calculate a normalized IPv4 network, masks, address range, broadcast address, and usable hosts.

Local processing

The address is calculated in this browser. This tool sends no calculation request.

Example: 10.20.30.40/20. Prefixes from /0 through /32 are supported.

Normalized CIDR
Subnet mask
Wildcard mask
Network address
Broadcast address
Address count
First usable
Last usable
Usable hosts

How to use it

  1. Enter an IPv4 address followed by a slash prefix.
  2. Select Calculate to normalize the network.
  3. Use the range and mask values when planning or checking a subnet.

Special prefixes

A /31 has two usable point-to-point addresses. A /32 identifies one host. Other subnets reserve network and broadcast addresses.

Read IPv4 CIDR and subnet ranges for worked examples.