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: 255.0.16.0/21
Addresses: 2048 (2¹¹)
First IP: 255.0.16.0 (0.16.0.255.in-addr.arpa)
Last IP: 255.0.23.255 (255.23.0.255.in-addr.arpa)

Owned By: IANA (Reserved (Future Use))
/8 Operated By: IANA (Reserved (Future Use))

Related Networks

255.0.0.0/8
254.0.0.0/8
255.0.16.0/20
255.0.16.0/32
255.0.23.255/32

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