CIDR Calculator

Calculate network address, broadcast address, usable host range, and subnet mask from a CIDR block.

Accepts IPv4 or IPv6, with or without a /prefix (defaults to /32 or /128).

Working…

Results will appear here.

Frequently asked questions

CIDR (Classless Inter-Domain Routing) notation, like 192.168.1.0/24, combines an IP address with a prefix length that specifies how many leading bits form the network portion of the address.

The first address in a subnet is the network address and the last (for IPv4) is the broadcast address - neither can be assigned to a host, so usable hosts = total addresses − 2 (except for /31 and /32 blocks).

Yes - enter any IPv6 address or CIDR block and the calculator will compute the equivalent network details.

About the CIDR Calculator

This tool takes any IPv4 or IPv6 address or CIDR block and instantly breaks it down into its network address, broadcast address, subnet mask, wildcard mask, and the range of usable host addresses - everything you need when planning subnets or troubleshooting network configuration.

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