NETWORK TOOLBOX

CIDR Calculator

Calculate network information, subnet masks and usable host ranges.

IP Address



CIDR Prefix



What is CIDR?

CIDR (Classless Inter-Domain Routing) is a method of allocating IP addresses and routing Internet traffic. A CIDR prefix determines how many bits are used for the network portion of an IP address, allowing efficient subnetting and IP address management.

Use this free subnet calculator to determine the network address, broadcast address, subnet mask, wildcard mask, usable host range and available host count for any IPv4 subnet.