/15 Subnet Mask: 255.254.0.0
A /15 prefix fixes the first 15 bits of the address as the network, leaving 17 bits for hosts. That gives 131,072 addresses, of which 131,070 can be assigned to hosts.
| CIDR notation | /15 |
| Subnet mask | 255.254.0.0 |
| Wildcard mask | 0.1.255.255 |
| Binary mask | 11111111.11111110.00000000.00000000 |
| Hex mask | 0xFFFE0000 |
| Total addresses | 131,072 |
| Usable hosts | 131,070 |
Example: 10.0.0.0/15
- Network address: 10.0.0.0
- First usable host: 10.0.0.1
- Last usable host: 10.1.255.254
- Broadcast address: 10.1.255.255
When to use a /15 subnet
Very large private networks. 10.0.0.0/8 is the largest private IPv4 range defined by RFC 1918.
- 128 /15 subnets fit in a /8.
Frequently Asked Questions
What is the subnet mask for /15?
The subnet mask for /15 is 255.254.0.0, and its wildcard (inverse) mask is 0.1.255.255.
How many hosts are in a /15?
A /15 contains 131,072 addresses. Subtracting the network and broadcast addresses leaves 131,070 usable hosts.