Free browser tool
Enter an IPv4 or IPv6 CIDR to calculate its normalized network, range, and address count locally in your browser.
The address before the slash does not have to be the network address. The calculator applies the prefix and returns the normalized CIDR, first address, last address, and size.
2001:db8:1234:5678::42/64 normalizes to 2001:db8:1234:5678::/64.IPv4 results include the subnet mask and broadcast address. IPv6 results focus on the prefix range and canonical text form instead.