IPv4 subnet calculator

Find subnet masks, address ranges and traditional host counts.

Traditional host counts exclude the network and broadcast addresses. /31 can use both addresses on point-to-point links; /32 identifies one address. These cases do not have a traditional host range.

Example: 192.168.1.10/24 → 192.168.1.0/24

Related guides

RFC 3021: /31 IPv4 point-to-point links