Class A Subnet and Host IP addresses
| # bits | Subnet Mask | CIDR | # Subnets | # Hosts | Nets * Hosts |
| 2 | 255.192.0.0 | /10 | 2 | 4194302 | 8388604 |
| 3 | 255.224.0.0 | /11 | 6 | 2097150 | 12582900 |
| 4 | 255.240.0.0 | /12 | 14 | 1048574 | 14680036 |
| 5 | 255.248.0.0 | /13 | 30 | 524286 | 15728580 |
| 6 | 255.252.0.0 | /14 | 62 | 262142 | 16252804 |
| 7 | 255.254.0.0 | /15 | 126 | 131070 | 16514820 |
| 8 | 255.255.0.0 | /16 | 254 | 65534 | 16645636 |
| 9 | 255.255.128.0 | /17 | 510 | 32766 | 16710660 |
| 10 | 255.255.192.0 | /18 | 1022 | 16382 | 16742404 |
| 11 | 255.255.224.0 | /19 | 2046 | 8190 | 16756740 |
| 12 | 255.255.240.0 | /20 | 4094 | 4094 | 16760836 |
| 13 | 255.255.248.0 | /21 | 8190 | 2046 | 16756740 |
| 14 | 255.255.252.0 | /22 | 16382 | 1022 | 16742404 |
| 15 | 255.255.254.0 | /23 | 32766 | 510 | 16710660 |
| 16 | 255.255.255.0 | /24 | 65534 | 254 | 16645636 |
| 17 | 255.255.255.128 | /25 | 131070 | 126 | 16514820 |
| 18 | 255.255.255.192 | /26 | 262142 | 62 | 16252804 |
| 19 | 255.255.255.224 | /27 | 524286 | 30 | 15728580 |
| 20 | 255.255.255.240 | /28 | 1048574 | 14 | 14680036 |
| 21 | 255.255.255.248 | /29 | 2097150 | 6 | 12582900 |
| 22 | 255.255.255.252 | /30 | 4194302 | 2 | 8388604 |