ABOUT SUBNET CALCULATOR

The subnet calculator lets you enter a subnet range (CIDR) and see IP address information about that range. It also lists each IP address in the range and automatically does a Reverse IP Lookup for you. You can type your range directly in CIDR notation, or use the optional Mask pull-down:

  • 74.125.227.0/29
  • 74.125.227.0 255.255.255.248
  • 74.125.227.0, then select Optional Mask from dropdown
This is a useful feature for service providers and network operator who frequently allocate and work with subnets. CIDR stands for Classless Inter-Domain Routing, and refers to the standard of dividing the entire IP address space into smaller networks of variable size.