/22 Subnet: Mask 255.255.252.0, 1,022 Usable Hosts
A /22 subnet has a subnet mask of 255.255.252.0 and contains 1,024 total IP addresses, of which 1,022 are usable host addresses (the network and broadcast addresses are reserved). A /22 contains 4 /24 networks.
| CIDR notation | /22 |
|---|---|
| Subnet mask | 255.255.252.0 |
| Wildcard mask | 0.0.3.255 |
| Mask in binary | 11111111.11111111.11111100.00000000 |
| Total addresses | 1,024 (2^10) |
| Usable hosts | 1,022 |
| Host bits | 10 |
Usable hosts in a /22 by platform
Cloud providers reserve more than the usual two addresses per subnet, so the same /22 gives you fewer usable IPs in the cloud than on a standard LAN.
| Platform | Reserved IPs | Usable hosts |
|---|---|---|
| Standard (network + broadcast) | 2 | 1,022 |
| AWS VPC | 5 | 1,019 |
| Microsoft Azure VNet | 5 | 1,019 |
| Google Cloud VPC | 4 | 1,020 |
| Oracle Cloud VCN | 3 | 1,021 |
Good to know
A /22 (1,024 addresses) is a frequent choice for a medium subnet, four /24s worth of space in one block.
How a /22 is calculated
- The /22 means the first 22 bits are the network portion, leaving 10 host bits.
- Total addresses = 2^(32 - 22) = 2^10 = 1,024.
- Usable hosts (standard) = 1,024 - 2 (network + broadcast) = 1,022.
- Subnet mask = 255.255.252.0; wildcard mask = 0.0.3.255.
Want to split a /22 into smaller subnets, see every address range, or plan a VLSM layout? Open the free subnet calculator →