/22 vs /23 — Subnet Comparison
A /22 subnet is 2× larger than a /23. Every additional bit in the prefix halves the address space — the 1-bit difference between these two means /22 has 21 = 2 times as many addresses.
1K IPs — medium site subnet
Typical Uses
- →Medium office floor VLAN
- →Application tier with ~500 hosts
- →Cloud subnet for a single microservice cluster
512 IPs — two /24s combined
Typical Uses
- →Two-floor office network
- →Expanded department VLAN
- →Route aggregation of two /24s
Key Differences
How 2 /23 Subnets Divide a /22
Example using 10.0.0.0/22 as the parent block.
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 10.0.0.0/23 | 10.0.0.0 | 10.0.0.1 | 10.0.1.254 | 10.0.1.255 | 510 |
| 2 | 10.0.2.0/23 | 10.0.2.0 | 10.0.2.1 | 10.0.3.254 | 10.0.3.255 | 510 |
FAQ
What is the difference between /22 and /23?
A /22 has 1,022 usable hosts
and a /23 has 510.
The subnet masks differ: /22 uses 255.255.252.0
while /23 uses 255.255.254.0.
Every additional bit in the prefix halves the number of addresses — so the 1-bit gap means
/22 is exactly 2× larger.
How many /23 subnets fit in a /22?
Exactly 2 /23 subnets fit perfectly inside one /22 with no wasted space. To split a /22 into /23s, just increment the last 1 bit of the network address for each new subnet.
Which should I choose?
/22 is typically used for: Medium office/application segment. /23 is better for: Aggregated /24 pair. Choose the smallest prefix that comfortably fits your host count — over-allocating wastes address space, but under-allocating means painful renumbering later.