Subnet Calculator
Enter an IPv4 address with a CIDR prefix and get the network address, broadcast, usable host range, subnet mask, wildcard and host count — instantly, in your browser.
private This tool runs entirely in your
browser. Nothing you enter is sent to our server or anyone else.
How to read the result
The network address is the first address in the block and identifies the subnet itself; the broadcast address is the last and reaches every host at once. The usable range is everything between them — those are the addresses you can actually assign. A /24 gives 256 total addresses and 254 usable (network and broadcast are reserved); each step down doubles the block, each step up halves it.
The wildcard mask is the subnet mask inverted, and it is what access-control lists and routing rules on Cisco-style gear expect instead of the mask.