IPv4 Subnet Calculator

This calculator and tool allows you to type an IP address in and get information on a particular subnet. Enter an IP or range in CIDR notation.

Network: 10.128.0.20/31
Addresses: 2 (2¹)
First IP: 10.128.0.20 (20.0.128.10.in-addr.arpa)
Last IP: 10.128.0.21 (21.0.128.10.in-addr.arpa)

Owned By: Private Use
/8 Operated By: Private Use (RFC1918)

Related Networks

10.0.0.0/8
9.0.0.0/8
11.0.0.0/8
10.128.0.20/30
10.128.0.20/32
10.128.0.21/32

You can also use some of the other examples such as:

0.0.0.0/0
1.0.0.0/8
127.0.0.1
30.0.0.0/8
192.168.0.0/16