/10 Subnet: Mask 255.192.0.0, 4,194,302 Usable Hosts
A /10 subnet has a subnet mask of 255.192.0.0 and contains 4,194,304 total IP addresses, of which 4,194,302 are usable host addresses (the network and broadcast addresses are reserved). A /10 contains 16,384 /24 networks.
| CIDR notation | /10 |
|---|---|
| Subnet mask | 255.192.0.0 |
| Wildcard mask | 0.63.255.255 |
| Mask in binary | 11111111.11000000.00000000.00000000 |
| Total addresses | 4,194,304 (2^22) |
| Usable hosts | 4,194,302 |
| Host bits | 22 |
Usable hosts in a /10 by platform
Cloud providers reserve more than the usual two addresses per subnet, so the same /10 gives you fewer usable IPs in the cloud than on a standard LAN.
| Platform | Reserved IPs | Usable hosts |
|---|---|---|
| Standard (network + broadcast) | 2 | 4,194,302 |
| AWS VPC | 5 | 4,194,299 |
| Microsoft Azure VNet | 5 | 4,194,299 |
| Google Cloud VPC | 4 | 4,194,300 |
| Oracle Cloud VCN | 3 | 4,194,301 |
Good to know
A /10 is the size of the carrier-grade NAT shared address space, 100.64.0.0/10 (RFC 6598), used by ISPs between the customer router and the public internet.
How a /10 is calculated
- The /10 means the first 10 bits are the network portion, leaving 22 host bits.
- Total addresses = 2^(32 - 10) = 2^22 = 4,194,304.
- Usable hosts (standard) = 4,194,304 - 2 (network + broadcast) = 4,194,302.
- Subnet mask = 255.192.0.0; wildcard mask = 0.63.255.255.
Want to split a /10 into smaller subnets, see every address range, or plan a VLSM layout? Open the free subnet calculator →