YurlieSubnet Calculator
Split an IPv4 network into equal subnets by specifying a new prefix length.
How subnetting works
Subnetting divides a large network into smaller networks (subnets) by borrowing bits from the host portion of the IP address. Each additional bit borrowed doubles the number of subnets while halving the number of hosts per subnet.
| Parent | New prefix | Subnets | Hosts/subnet |
|---|---|---|---|
/24 | /25 | 2 | 126 |
/24 | /26 | 4 | 62 |
/24 | /27 | 8 | 30 |
/24 | /28 | 16 | 14 |
/24 | /30 | 64 | 2 |
/16 | /24 | 256 | 254 |
Frequently Asked Questions
What is VLSM?
VLSM (Variable Length Subnet Masking) allows subnets of different sizes within the same network — unlike this tool which splits into equal subnets. VLSM is used when different parts of a network need different numbers of hosts.
Why can't I split into /31 or /32?
A /31 subnet has only 2 addresses (no usable hosts in traditional networking, though RFC 3021 allows point-to-point use). A /32 is a single host route. This tool limits to /30 which has 2 usable hosts.