/10 Subnet
4 million IPs — quarter of a /8
A /10 contains just over 4 million addresses. Sometimes used to allocate a major region within a large enterprise 10.x.x.x plan.
Common Use Cases
- → Major regional segment in enterprise
- → Large cloud region allocation
Example /10 Networks
| CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|
| 10.0.0.0/10 | 10.0.0.0 | 10.0.0.1 | 10.63.255.254 | 10.63.255.255 | 4,194,302 |
| 172.0.0.0/10 | 172.0.0.0 | 172.0.0.1 | 172.63.255.254 | 172.63.255.255 | 4,194,302 |
| 172.0.0.0/10 | 172.0.0.0 | 172.0.0.1 | 172.63.255.254 | 172.63.255.255 | 4,194,302 |
| 192.128.0.0/10 | 192.128.0.0 | 192.128.0.1 | 192.191.255.254 | 192.191.255.255 | 4,194,302 |
| 192.128.0.0/10 | 192.128.0.0 | 192.128.0.1 | 192.191.255.254 | 192.191.255.255 | 4,194,302 |
| 10.0.0.0/10 | 10.0.0.0 | 10.0.0.1 | 10.63.255.254 | 10.63.255.255 | 4,194,302 |
How /10 Compares
| Prefix | Total IPs | Usable Hosts | Subnet Mask | Typical Use |
|---|---|---|---|---|
| /7 | 33,554,432 | 33,554,430 | 254.0.0.0 | — |
| /8 | 16,777,216 | 16,777,214 | 255.0.0.0 | Entire private Class A or ISP allocation |
| /9 | 8,388,608 | 8,388,606 | 255.128.0.0 | Large regional allocations |
| /10 ◀ | 4,194,304 | 4,194,302 | 255.192.0.0 | Enterprise regional segment |
| /11 | 2,097,152 | 2,097,150 | 255.224.0.0 | — |
| /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 | — |
Frequently Asked Questions
How many IPs are in a /10?
A /10 subnet contains 4,194,304 total IP addresses and 4,194,302 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 /10?
The subnet mask for a /10 is 255.192.0.0.
In CIDR notation, the prefix length /10 means
the first 10 bits of the address are the network portion.
The wildcard (inverse) mask is 0.63.255.255.
How many /10 subnets fit in a /9?
Exactly 2 — a /9 can be split into two /10 subnets of equal size. Each /10 subnet has 4,194,302 usable hosts, compared to 8,388,606 in the parent /9.