About CIDR Calculator

What is CIDR?

CIDR (Classless Inter-Domain Routing) is a method for allocating IP addresses and routing IP packets. It was introduced in 1993 to replace the earlier addressing architecture of classful networking.

Features

  • Interactive binary representation
  • Network class detection
  • Carrier Grade NAT detection
  • Subnet mask calculation
  • Available IP range calculation

How It Works

Enter an IP address followed by a forward slash and the number of bits used for the network portion. For example, 192.168.1.0/24 represents a network with 24 bits used for the network portion and 8 bits for host addresses.