IPv4 subnet calculator (CIDR)
Compute network address, broadcast, mask and host count from an IP and CIDR prefix.
Network address
192.168.1.0/24
Subnet mask255.255.255.0
Broadcast192.168.1.255
Host range192.168.1.1 – 192.168.1.254
Usable hosts254
How the calculation works
The CIDR prefix (e.g. /24) defines the mask. The network address is IP AND mask; the broadcast fills the host bits with 1. Usable hosts = 2^(32−prefix) − 2.
Frequently asked questions
Why "− 2" hosts?
One address is the network and another is the broadcast; neither can be assigned to a host.
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Updated on June 18, 2026 · by Rafael Rossi · Methodology & sources