Last reviewed: May 2026
A /26 subnet contains 64 total IP addresses and 62 usable host addresses. The "/26" prefix means 26 bits are used for the network portion, leaving 6 bits (26 = 64) for host addressing. The /26 is a critical prefix in Azure networking — it is the minimum required size for AzureFirewallSubnet, AzureBastionSubnet, and ApplicationGatewaySubnet.
Calculate any /26 subnet instantly →| Property | Value |
|---|---|
| Prefix length | /26 |
| Subnet mask | 255.255.255.192 |
| Wildcard mask | 0.0.0.63 |
| Total addresses | 64 |
| Usable host addresses | 62 |
| Network address | x.x.x.0 (must align to multiples of 64: .0, .64, .128, .192) |
| Broadcast address | x.x.x.63 (last address in the block) |
| Binary mask | 11111111.11111111.11111111.11000000 |
| AWS usable hosts | 59 (AWS reserves 5 IPs per subnet) |
| Azure usable hosts | 59 (Azure reserves 5 IPs per subnet) |
/26 is the minimum size for several critical Azure managed subnets:
Using /27 or smaller for these subnets will cause Azure deployment errors. Always provision /26 or larger for these managed services.
In an AWS VPC, a /26 subnet provides 59 usable IPs after AWS reserves 5 addresses. This makes /26 a popular choice for small-to-medium workload subnets such as ECS task subnets, Lambda VPC subnets, and development environment subnets.
| CIDR | Subnet Mask | Total IPs | Usable Hosts | AWS Usable | Typical Use |
|---|---|---|---|---|---|
| /24 | 255.255.255.0 | 256 | 254 | 251 | Standard subnet — most common |
| /25 | 255.255.255.128 | 128 | 126 | 123 | Half of /24; medium workload subnet |
| /26 | 255.255.255.192 | 64 | 62 | 59 | Azure Firewall/Bastion minimum; small AWS workload |
| /27 | 255.255.255.224 | 32 | 30 | 27 | Azure GatewaySubnet; infrastructure segment |
A /24 block contains 2(26−24) = 4 subnets of /26 size. For example, 192.168.1.0/24 can be subdivided into 192.168.1.0/26, 192.168.1.64/26, 192.168.1.128/26, and 192.168.1.192/26. Each block starts on a multiple of 64.
Try the subnet splitter in SubnetSolver →