Network Math Open homepage tool

IPv4 Subnet Calculator

Convert prefixes and CIDR notation into usable IPv4 ranges and inspect addresses inside each subnet.

Networks

IPv4 Subnet Browser

Search by subnet prefix like 216.73.217 or CIDR notation like 10.0.0.0/16.

Why it helps

This calculator helps you read subnet boundaries, understand the size of a range and move through neighboring IPv4 blocks when debugging firewall rules, inventory or access scope.