What is a /22 subnet? 1,024 IPs and why it's the office-network sweet spot

How this is calculated

With roughly 1,000 usable addresses, a /22 comfortably handles a mid-size office of 200-300 employees, each with a laptop, phone, and maybe a couple of lab or test devices. The broadcast domain at this size is manageable on modern switched networks. A /22 is the most common subnet size for cloud VPC deployments where you want each availability zone to have room for auto-scaling without running out of IPs during a scale-out event.

Verdict

The /22 mask 255.255.252.0 reserves 22 bits for the network and leaves 10 bits for hosts, which is 1,024 total addresses and 1,022 usable. That covers a mid-size office of 200-300 employees each carrying a laptop, phone, IoT device, and guest device, with room for the auto-scaling scale-out events that cloud VPC subnets have to absorb. Pushing past roughly 1,000 hosts on a flat segment starts to weigh on broadcast traffic on consumer switches, which is the practical reason /22 is the de facto ceiling for L2 domains in 2026. above it, multiple VLANs each with their own /22 keep broadcast domains manageable without forcing a full renumbering.