Range to CIDR
A simple IPv4 range calculator
IPv4 network utility

Range to CIDR

Turn any IPv4 start and end address into the smallest set of CIDR blocks that covers your range exactly.

Enter an IP range

Set the first and last address in your range.

Enter valid IPv4 addresses (0–255 in each octet).

CIDR result

Your matching network blocks will appear here.

Ready when you areEnter a range to see its CIDR blocks.
A range can span multiple networks. The result uses the fewest CIDR blocks needed to cover every address without including extras.
Exact coverageEvery address in your range, with no extras.
Any range sizeFrom a single IP to the full IPv4 space.
Quick to copyCopy one block or the complete result.