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Enter a network in CIDR notation (e.g. 192.168.1.0/24) to get the network address, broadcast, netmask, and usable address range.
CIDR describes a whole block of addresses without listing each one. It underlies firewall rules, allowlists, and internal network segmentation.
A /24 network in IPv4 gives 256 total addresses, while a /30 only gives 4, with 2 usable for hosts.
Frequently asked questions
This calculator is built for IPv4. IPv6 prefixes are much larger (e.g. /64).
The addresses assignable to hosts, excluding the network address and broadcast (except in /31 and /32).