Subnet Calculator

About this tool

With this tool you can calculate subnet information. Enter an IP address and a subnet mask (as prefix or as long mask).

The tool displays the network address, the first and last usable IP address, and the broadcast address. Additionally, the subnet can be split into multiple smaller subnets.

Input

Enter an IP address and either a prefix length (e.g. /24) or a subnet mask (e.g. 255.255.255.0). The two values will be automatically synchronized.

IP Address

Prefix/

Subnet Mask

Quick Select

Local (127.0.0.0/8)

Private, Class A (10.0.0.0/8)

CGN (100.64.0.0/10)

Private, Class B (172.16.0.0/12)

Private, Class C (192.168.0.0/16)