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 |