Last reviewed: May 2026
A /22 subnet uses 22 bits for the network portion of an IPv4 address, leaving 10 bits for host addressing. This produces 1,024 total IP addresses and 1,022 usable hosts. A /22 spans exactly 4 consecutive /24 blocks, making it a natural choice when a single /24 is too small but a /20 is overkill.
Calculate any /22 subnet instantly →| Property | Value |
|---|---|
| Prefix length | /22 |
| Subnet mask | 255.255.252.0 |
| Wildcard mask | 0.0.3.255 |
| Total addresses | 1,024 |
| Usable host addresses | 1,022 |
| Network address | x.x.x.0 (third octet must be multiple of 4: .0, .4, .8, .12, …) |
| Broadcast address | x.x.3.255 (last address in the 4-block span) |
| Binary mask | 11111111.11111111.11111100.00000000 |
| AWS usable hosts | 1,019 (AWS reserves 5 IPs per subnet) |
Conceptually, a /22 is exactly four /24 subnets aggregated into one block. The third octet of the network address must start on a multiple of 4 — so valid /22 networks include 10.0.0.0/22, 10.0.4.0/22, 10.0.8.0/22, etc. This makes /22 a useful summary route for announcing groups of /24s in BGP.
| Subnet | Range | Spans /24s | AWS Usable |
|---|---|---|---|
| 10.0.0.0/22 | 10.0.0.0 – 10.0.3.255 | .0, .1, .2, .3 | 1,019 |
| 10.0.4.0/22 | 10.0.4.0 – 10.0.7.255 | .4, .5, .6, .7 | 1,019 |
| 10.0.8.0/22 | 10.0.8.0 – 10.0.11.255 | .8, .9, .10, .11 | 1,019 |
| 10.0.12.0/22 | 10.0.12.0 – 10.0.15.255 | .12, .13, .14, .15 | 1,019 |
| Parent Block | Number of /22s |
|---|---|
| /16 | 64 |
| /20 | 4 |
| /24 | 0.25 (a /22 is 4× larger than a /24) |
| CIDR | Subnet Mask | Total IPs | Usable Hosts | AWS Usable | Typical Use |
|---|---|---|---|---|---|
| /20 | 255.255.240.0 | 4,096 | 4,094 | 4,091 | EKS node groups, large AZ subnets |
| /21 | 255.255.248.0 | 2,048 | 2,046 | 2,043 | Large campus segment |
| /22 | 255.255.252.0 | 1,024 | 1,022 | 1,019 | Large office VLAN, Azure VM subnets |
| /23 | 255.255.254.0 | 512 | 510 | 507 | Medium office, 2×/24 merged |
| /24 | 255.255.255.0 | 256 | 254 | 251 | Standard workload subnet |
A /22 subnet has 1,022 usable host addresses from a total of 1,024 IPs. Two addresses are reserved: the network address and the broadcast address. In AWS, 1,019 IPs are usable after the 5 reserved addresses are subtracted.
A /22 spans exactly 4 consecutive /24 blocks. For example, 10.0.0.0/22 covers 10.0.0.0/24, 10.0.1.0/24, 10.0.2.0/24, and 10.0.3.0/24. The third octet of a /22 network address must be a multiple of 4 (0, 4, 8, 12, 16, etc.).
The subnet mask for a /22 network is 255.255.252.0. In binary, 22 bits are set to 1 followed by 10 bits of 0: 11111111.11111111.11111100.00000000.