/6 Subnet: Mask 252.0.0.0, 67,108,862 Usable Hosts
A /6 subnet has a subnet mask of 252.0.0.0 and contains 67,108,864 total IP addresses, of which 67,108,862 are usable host addresses (the network and broadcast addresses are reserved). A /6 contains 262,144 /24 networks.
| CIDR notation | /6 |
|---|---|
| Subnet mask | 252.0.0.0 |
| Wildcard mask | 3.255.255.255 |
| Mask in binary | 11111100.00000000.00000000.00000000 |
| Total addresses | 67,108,864 (2^26) |
| Usable hosts | 67,108,862 |
| Host bits | 26 |
Usable hosts in a /6 by platform
Cloud providers reserve more than the usual two addresses per subnet, so the same /6 gives you fewer usable IPs in the cloud than on a standard LAN.
| Platform | Reserved IPs | Usable hosts |
|---|---|---|
| Standard (network + broadcast) | 2 | 67,108,862 |
| AWS VPC | 5 | 67,108,859 |
| Microsoft Azure VNet | 5 | 67,108,859 |
| Google Cloud VPC | 4 | 67,108,860 |
| Oracle Cloud VCN | 3 | 67,108,861 |
Good to know
A /6 subnet has a 252.0.0.0 mask and 67,108,864 total addresses (67,108,862 usable). Each step from /6 to /7 halves the block; each step back to /5 doubles it.
How a /6 is calculated
- The /6 means the first 6 bits are the network portion, leaving 26 host bits.
- Total addresses = 2^(32 - 6) = 2^26 = 67,108,864.
- Usable hosts (standard) = 67,108,864 - 2 (network + broadcast) = 67,108,862.
- Subnet mask = 252.0.0.0; wildcard mask = 3.255.255.255.
Want to split a /6 into smaller subnets, see every address range, or plan a VLSM layout? Open the free subnet calculator →