Why a range may require several blocks
CIDR networks have power-of-two sizes and must start on matching boundaries. An arbitrary range therefore often needs several non-overlapping CIDR blocks to cover it exactly.
Common uses
The result can help prepare firewall allowlists, routing rules, cloud network configurations, and documentation. Confirm that the destination system interprets both endpoints inclusively.
Range versus subnet
This tool starts with two endpoints. The Subnet Calculator starts with one network and helps divide it.