The following table shows the IPv4 network subnet prefixes, subnet masks, and the number of usable hosts.
| Prefix size | Network mask | Available subnets | Usable hosts per subnet | Total usable hosts |
| /24 | 255.255.255.0 | 1 | 254 | 254 |
| /25 | 255.255.255.128 | 2 | 126 | 252 |
| /26 | 255.255.255.192 | 4 | 62 | 248 |
| /27 | 255.255.255.224 | 8 | 30 | 240 |
| /28 | 255.255.255.240 | 16 | 14 | 224 |
| /29 | 255.255.255.248 | 32 | 6 | 192 |
| /30 | 255.255.255.252 | 64 | 2 | 128 |
| /31 | 255.255.255.254 | 128 | 2 * | 256 |
* for point-to-point links only
In a subnet the following two addresses cannot be assigned to hosts:
- the first address is the address of the subnet,
- the last address is the broadcast address to all hosts.
