/3 Subnet
536,870,912 total IPs — 536,870,910 usable hosts.
Example /3 Networks
| CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|
| 0.0.0.0/3 | 0.0.0.0 | 0.0.0.1 | 31.255.255.254 | 31.255.255.255 | 536,870,910 |
| 160.0.0.0/3 | 160.0.0.0 | 160.0.0.1 | 191.255.255.254 | 191.255.255.255 | 536,870,910 |
| 160.0.0.0/3 | 160.0.0.0 | 160.0.0.1 | 191.255.255.254 | 191.255.255.255 | 536,870,910 |
| 192.0.0.0/3 | 192.0.0.0 | 192.0.0.1 | 223.255.255.254 | 223.255.255.255 | 536,870,910 |
| 192.0.0.0/3 | 192.0.0.0 | 192.0.0.1 | 223.255.255.254 | 223.255.255.255 | 536,870,910 |
| 0.0.0.0/3 | 0.0.0.0 | 0.0.0.1 | 31.255.255.254 | 31.255.255.255 | 536,870,910 |
How /3 Compares
| Prefix | Total IPs | Usable Hosts | Subnet Mask | Typical Use |
|---|---|---|---|---|
| /0 | 4,294,967,296 | 4,294,967,294 | 0.0.0.0 | Routing & firewalls only |
| /1 | 2,147,483,648 | 2,147,483,646 | 128.0.0.0 | — |
| /2 | 1,073,741,824 | 1,073,741,822 | 192.0.0.0 | — |
| /3 ◀ | 536,870,912 | 536,870,910 | 224.0.0.0 | — |
| /4 | 268,435,456 | 268,435,454 | 240.0.0.0 | — |
| /5 | 134,217,728 | 134,217,726 | 248.0.0.0 | — |
| /6 | 67,108,864 | 67,108,862 | 252.0.0.0 | — |
Frequently Asked Questions
How many IPs are in a /3?
A /3 subnet contains 536,870,912 total IP addresses and 536,870,910 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 /3?
The subnet mask for a /3 is 224.0.0.0.
In CIDR notation, the prefix length /3 means
the first 3 bits of the address are the network portion.
The wildcard (inverse) mask is 31.255.255.255.
How many /3 subnets fit in a /2?
Exactly 2 — a /2 can be split into two /3 subnets of equal size.