CIDR
The first address on any block is the network address, and the last address is the broadcast, hence why there are always two fewer actual hosts than potential hosts.
| Prefix | Potential hosts | Actual hosts | Netmask | Subnets | Address range | Broadcast address |
|---|---|---|---|---|---|---|
| /31 | 2 | 0 | 255.255.255.254 | 128 | ||
| /30 | 4 | 255.255.255.252 | 64 | |||
| /29 | 8 | 255.255.255.248 | 32 | |||
| /28 | 16 | 255.255.255.240 | 16 | |||
| /27 | 32 | 255.255.255.224 | 8 | |||
| /26 | 64 | 255.255.255.192 | 4 | |||
| /25 | 128 | 255.255.255.128 | 2 | |||
| /24 | 256 | 255.255.255.0 | 1 | |||
| /23 | 512 | 255.255.254.0 | 128 | |||
| /22 | 1024 | 255.255.252.0 | 64 | |||
| /21 | 2048 | 255.255.248.0 | 32 | |||
| /20 | 4096 | 255.255.240.0 | 16 | |||
| /19 | 8192 | 255.255.224.0 | 8 | |||
| /18 | 16384 | 255.255.192.0 | 4 | |||
| /17 | 32768 | 255.255.128.0 | 2 | |||
| /16 | 65536 | 255.255.0.0 | 1 | |||
| /15 | 131072 | 255.254.0.0 | 128 | |||
| /14 | 262144 | 255.252.0.0 | 64 | |||
| /13 | 524288 | 255.248.0.0 | 32 | |||
| /12 | 1048576 | 255.240.0.0 | 16 | |||
| /11 | 2097152 | 255.224.0.0 | 8 | |||
| /10 | 4194304 | 255.192.0.0 | 4 | |||
| /9 | 8388608 | 255.128.0.0 | 2 | |||
| /8 | 16777216 | 255.0.0.0 | 1 | |||
| /7 | 33554432 | 254.0.0.0 | 128 | |||
| /6 | 67108864 | 252.0.0.0 | 64 | |||
| /5 | 134217728 | 248.0.0.0 | 32 | |||
| /4 | 268435456 | 240.0.0.0 | 16 | |||
| /3 | 536870912 | 224.0.0.0 | 8 | |||
| /2 | 1073741824 | 192.0.0.0 | 4 | |||
| /1 | 2147483648 | 128.0.0.0 | 2 | |||
| /0 | 4294967296 | 0.0.0.0 | 1 |