What this calculator shows
A CIDR prefix states how many leading address bits identify the network. This tool aligns the entered address to that boundary and reports the network, broadcast, subnet mask, inverse wildcard mask, address count, and common address classification.
Worked example
For 192.168.1.42/24, the first 24 bits define the network. The aligned network is 192.168.1.0 and the broadcast address is 192.168.1.255.
When to use the subnet planner
Use the Subnet Calculator when you need to divide a network into smaller blocks. This page is intended for quick conversion and inspection.