Subnet Splitter – Divide an IP Network Into Equal Subnets
Cut any IPv4 CIDR block into equal-sized subnets — either a fixed number of parts or all the way to a chosen prefix. The CCNA classic: how many /26s fit in a /24?
Split results for 192.168.1.0/24
192.168.1.0/24 splits into 4 × /26.
| # | Subnet (CIDR) | Address range | Usable hosts | Wildcard mask |
|---|---|---|---|---|
| 1 | 192.168.1.0/26 | 192.168.1.1 – 192.168.1.62 | 62 | 0.0.0.63 |
| 2 | 192.168.1.64/26 | 192.168.1.65 – 192.168.1.126 | 62 | 0.0.0.63 |
| 3 | 192.168.1.128/26 | 192.168.1.129 – 192.168.1.190 | 62 | 0.0.0.63 |
| 4 | 192.168.1.192/26 | 192.168.1.193 – 192.168.1.254 | 62 | 0.0.0.63 |
Equal-sized split vs VLSM
This tool divides the base network into identical subnets — every piece has the same prefix and the same number of addresses. That is what fixed-length subnetting (FLSM) looks like, and it is the setup behind exam staples like "how many /26s fit in a /24?".
When subnets need different sizes — a /26 for users, a /30 for an uplink — use the VLSM calculator instead, which allocates right-sized blocks from your host requirements.
Frequently asked questions
How many /26 subnets fit in a /24?
4. A /24 covers 256 addresses and each /26 covers 64, so 256 ÷ 64 = 4. Set the base to 192.168.1.0/24 and parts to 4 to see them side by side.
How many /27s fit in a /25?
4. A /25 covers 128 addresses and each /27 covers 32, so 128 ÷ 32 = 4.
Can I split a /30 into /31s?
Yes — exactly 2 point-to-point links. A /30 covers 4 addresses and each /31 covers 2, and both addresses in a /31 are usable per RFC 3021, so no address is wasted on a two-endpoint link. Try base 10.0.0.0/30 with parts 2.
Why must the number of parts be a power of two?
CIDR blocks are binary-aligned: every split halves the block size, so equal-sized pieces of one block always come in counts of 2, 4, 8 and so on. A count like 3 cannot be expressed as equal CIDR blocks, which is exactly the case the VLSM calculator exists for.