Subnet Calculator
IPv4 and IPv6 subnet math, equal-size splitting, range-to-CIDR conversion, and CIDR aggregation.
Binary breakdown
Split into equal subnets
This splits into equal-size subnets. Variable-length (VLSM) planning is not included.
This tool calculates IPv4 and IPv6 subnet ranges (network address, usable host range, broadcast where applicable, and total address count), splits a network into equal-size subnets, converts an arbitrary address range into the minimal covering set of CIDR blocks, and merges a list of CIDR blocks or addresses into the smallest equivalent set. It also flags when a calculated network falls within an IANA special-purpose address block (private-use, carrier-grade NAT, documentation, loopback, link-local, multicast, and similar reserved ranges), citing the governing RFC.