Calculate an IPv4 network, subnet mask, wildcard mask, address range and usable-host count from an address and CIDR prefix.
Printed from Calxy · https://www.calxy.net/other/ip-subnet-calculator
Four decimal octets, for example 192.168.1.42.
0 – 32
Network in CIDR notation
192.168.1.0/24
For /31, both addresses are usable on an RFC 3021 point-to-point link. /32 denotes one host. Other prefixes reserve the first and last addresses. This arithmetic does not determine routability, allocation rights or firewall policy.
A /p block contains 2^(32 − p) IPv4 addresses.
Clear the host bits to find the network, then set them to find the final address.
A /p block has 2^(32 − p) addresses. Clear host bits for the network boundary. Ordinary subnets reserve network and broadcast addresses; /31 point-to-point links and /32 hosts are handled separately.
192.168.1.42/24 belongs to 192.168.1.0/24. Its mask is 255.255.255.0 and ordinary usable addresses run from .1 through .254.
RFC 3021 permits both addresses on a point-to-point link. This does not mean every network type or device supports that configuration.
Last updated . Results are estimates for informational purposes only.