/15 Subnet
131,072 total IPs — 131,070 usable hosts.
Example /15 Networks
| CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|
| 10.0.0.0/15 | 10.0.0.0 | 10.0.0.1 | 10.1.255.254 | 10.1.255.255 | 131,070 |
| 172.16.0.0/15 | 172.16.0.0 | 172.16.0.1 | 172.17.255.254 | 172.17.255.255 | 131,070 |
| 172.30.0.0/15 | 172.30.0.0 | 172.30.0.1 | 172.31.255.254 | 172.31.255.255 | 131,070 |
| 192.168.0.0/15 | 192.168.0.0 | 192.168.0.1 | 192.169.255.254 | 192.169.255.255 | 131,070 |
| 192.168.0.0/15 | 192.168.0.0 | 192.168.0.1 | 192.169.255.254 | 192.169.255.255 | 131,070 |
| 10.0.0.0/15 | 10.0.0.0 | 10.0.0.1 | 10.1.255.254 | 10.1.255.255 | 131,070 |
How /15 Compares
| Prefix | Total IPs | Usable Hosts | Subnet Mask | Typical Use |
|---|---|---|---|---|
| /12 | 1,048,576 | 1,048,574 | 255.240.0.0 | RFC 1918 Class B range |
| /13 | 524,288 | 524,286 | 255.248.0.0 | — |
| /14 | 262,144 | 262,142 | 255.252.0.0 | — |
| /15 ◀ | 131,072 | 131,070 | 255.254.0.0 | — |
| /16 | 65,536 | 65,534 | 255.255.0.0 | Cloud VPC CIDR, campus network |
| /17 | 32,768 | 32,766 | 255.255.128.0 | Large segment within a /16 |
| /18 | 16,384 | 16,382 | 255.255.192.0 | VPC segment |
Frequently Asked Questions
How many IPs are in a /15?
A /15 subnet contains 131,072 total IP addresses and 131,070 usable host addresses. The network address (first IP) and broadcast address (last IP) are reserved and cannot be assigned to hosts.
What is the subnet mask for /15?
The subnet mask for a /15 is 255.254.0.0.
In CIDR notation, the prefix length /15 means
the first 15 bits of the address are the network portion.
The wildcard (inverse) mask is 0.1.255.255.
How many /15 subnets fit in a /14?
Exactly 2 — a /14 can be split into two /15 subnets of equal size.