IPv4 subnet calculator (CIDR)
Network address, broadcast, mask and number of hosts from an IP and prefix.
How it works
Mask = 32 bits with the first "prefix" bits set to 1. Network = IP AND mask. Broadcast = network OR (NOT mask). Usable hosts = 2^(32 − prefix) − 2.
Results are for guidance only and do not replace professional advice.
Worked example
With the default values:
- IP address / prefix192.168.10.37/26
you get:
- Network192.168.10.0/26
- Subnet mask255.255.255.192
- Broadcast192.168.10.63
- Host range192.168.10.1 – 192.168.10.62
Frequently asked questions
How does the “IPv4 subnet calculator” tool work?
Mask = 32 bits with the first "prefix" bits set to 1. Network = IP AND mask. Broadcast = network OR (NOT mask). Usable hosts = 2^(32 − prefix) − 2.
What do I need to enter?
Just fill in: ip address / prefix. The result updates as you type.
Can you give an example?
IP address / prefix: 192.168.10.37/26 → Network: 192.168.10.0/26; Subnet mask: 255.255.255.192.
Is this calculator free, and is my data private?
Yes. HOD Calc is completely free with no sign-up. The calculation runs in your browser: nothing you type is sent or stored.