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: 204.0.3.128/25
Addresses: 128 (2⁷)
First IP: 204.0.3.128 (128.3.0.204.in-addr.arpa)
Last IP: 204.0.3.255 (255.3.0.204.in-addr.arpa)

/8 Operated By: ARIN

Related Networks

204.0.0.0/8
203.0.0.0/8
205.0.0.0/8
204.0.3.0/24
204.0.3.128/32
204.0.3.255/32

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