Subnet Calculator
Calculate IPv4 networks, host ranges, and subnet masks.
Look up common service ports and transport protocols.
Your result will appear here.
Enter your input, then run the tool.Select Run tool to use common ports reference.
Use the labeled units and valid search by service or port. The Example button supplies a reproducible starting input.
Calculate IPv4 networks, host ranges, and subnet masks.
Query public PTR records for an IPv4 address.
Check IPv6 address syntax, including compressed notation.