The /22 prefix: 1,024 addresses, four /24s wide
A /22 gives you 10 host bits: 1,024 addresses with the mask 255.255.252.0. The third octet advances in steps of 4, so 192.168.0.0/22 covers 192.168.0.0 through 192.168.3.255 — four classful Class Cs fused into one broadcast domain.
This is the natural size for a mid-size office, a busy Wi-Fi network, or a server segment that outgrew its /24: big enough to stop worrying about exhaustion, small enough that broadcast traffic stays civilized.
| Prefix length | /22 |
| Subnet mask | 255.255.252.0 |
| Wildcard mask | 0.0.3.255 |
| Total addresses | 1,024 |
| Usable hosts | 1,022 |
When a /24 stops being enough
The tell-tale moment is a DHCP scope hovering above 80% full. Rather than bolting on a second /24 and routing between the two, many admins renumber once into a /22 and quadruple their headroom. A single broadcast domain of a thousand hosts is fine on modern switching; chatty discovery protocols get annoying long before the address math becomes a problem.
DHCP pool planning at this size
With 1,022 usable addresses, a sane split is a static band — say the first /24's worth — for servers, printers, and reservations, with the remainder for dynamic clients. Keep lease times short on guest-heavy networks: a /22 feels infinite until a conference fills it with phones at one lease per MAC address.
CIDR Calculator
Run the math on 10.0.0.0/22 — or any other block
Frequently asked questions
How many IP addresses are in a /22?
1,024 in total (2^10), with 1,022 usable once the network and broadcast addresses are taken out.
What is the subnet mask of a /22?
255.255.252.0. The 252 in the third octet means six network bits there, so networks start on multiples of 4: .0, .4, .8 and so on.
How many /24s are in a /22?
Exactly four. A /23 merges two /24s, and a /22 doubles that again.
Is a /22 too big for one VLAN?
Usually not. A thousand hosts in a single broadcast domain is well within what modern switches handle; the practical limits are broadcast chatter and failure-domain size, not the raw address count.