IPv4 Subnet Splitter (VLSM Calculator)
Divide a network such as 10.0.0.0/16 into equal smaller subnets and see each one's address range.
How it works
Each extra bit of prefix length halves the size of a subnet and doubles the number of them: splitting a /24 into /26 networks gives 2(26-24) = 4 subnets of 64 addresses each (62 usable). This tool splits into equal-sized subnets; for subnets of different sizes (VLSM), split in stages, starting with the largest requirement.
Output is limited to the first 1,024 subnets.
Frequently asked questions
How many subnets can I make from a /24?
Two /25s, four /26s, eight /27s, sixteen /28s, 32 /29s or 64 /30s.
What is VLSM?
Variable Length Subnet Masking: using different prefix lengths within one network so each subnet fits its host count without waste.
Why are two addresses lost in every subnet?
The first is the network address and the last is the broadcast address, so usable hosts are total minus two (except /31 and /32).