IPv4 Subnet Calculator

Runs locally in your browser. Nothing is uploaded.

Enter an IPv4 address and CIDR prefix to calculate its subnet. Copy the result for your documentation or scripts.

Subnet input

Example: 192.168.1.1/24. Supported prefixes: /0 to /32.

How to read the result

The network address identifies the subnet. The subnet mask and wildcard mask describe its boundaries. The host range shows the addresses available under conventional IPv4 subnet rules.

A /31 uses point-to-point semantics with two usable addresses. A /32 represents a single host. Neither has a broadcast address in this result, so that field is null.

Host counts describe subnet arithmetic. They do not determine whether an address is reserved, publicly routable or available on your network.