| Hex Mask | bit | dotted quad | Hosts | Networks |
| 80.00.00.00 | /1 | 128.0.0.0 | 2048 M | 128 A |
| C0.00.00.00 | /2 | 192.0.0.0 | 1024 M | 64 A |
| E0.00.00.00 | /3 | 224.0.0.0 | 512 M | 32 A |
| F0.00.00.00 | /4 | 240.0.0.0 | 256 M | 16 A |
| F8.00.00.00 | /5 | 248.0.0.0 | 128 M | 8 A |
| FC.00.00.00 | /6 | 252.0.0.0 | 64 M | 4 A |
| FE.00.00.00 | /7 | 254.0.0.0 | 32 M | 2 A |
| FF.00.00.00 | /8 | 255.0.0.0 | 16 M | 1 A |
| FF.80.00.00 | /9 | 255.128.0.0 | 8 M | 128 B |
| FF.C0.00.00 | /10 | 255.192.0.0 | 4 M | 64 B |
| FF.E0.00.00 | /11 | 255.224.0.0 | 2 M | 32 B |
| FF.F0.00.00 | /12 | 255.240.0.0 | 1024 K | 16 B |
| FF.F8.00.00 | /13 | 255.248.0.0 | 512 K | 8 B |
| FF.FC.00.00 | /14 | 255.252.0.0 | 256 K | 4 B |
| FF.FE.00.00 | /15 | 255.254.0.0 | 128 K | 2 B |
| FF.FF.00.00 | /16 | 255.255.0.0 | 64 K | 1 B |
| FF.FF.80.00 | /17 | 255.255.128.0 | 32 K | 128 C |
| FF.FF.C0.00 | /18 | 255.255.192.0 | 16 K | 64 C |
| FF.FF.E0.00 | /19 | 255.255.224.0 | 8 K | 32 C |
| FF.FF.F0.00 | /20 | 255.255.240.0 | 4 K | 16 C |
| FF.FF.F8.00 | /21 | 255.255.248.0 | 2 K | 8 C |
| FF.FF.FC.00 | /22 | 255.255.252.0 | 1 K | 4 C |
| FF.FF.FE.00 | /23 | 255.255.254.0 | 512 | 2 C |
| FF.FF.FF.00 | /24 | 255.255.255.0 | 256 | 1 C |
| FF.FF.FF.80 | /25 | 255.255.255.128 | 128 | - |
| FF.FF.FF.C0 | /26 | 255.255.255.192 | 64 | - |
| FF.FF.FF.E0 | /27 | 255.255.255.224 | 32 | - |
| FF.FF.FF.F0 | /28 | 255.255.255.240 | 16 | - |
| FF.FF.FF.F8 | /29 | 255.255.255.248 | 8 | - |
| FF.FF.FF.FC | /30 | 255.255.255.252 | 4 | - |
| FF.FF.FF.FE | /31 | 255.255.255.254 | This space is not usable. | |
| FF.FF.FF.FF | /32 | 255.255.255.255 | This is a single host route. | |
| No. bits | Mask | Effective Subnets | Effective Hosts |
| 2 | 255.255.192.0 | 2 | 16382 |
| 3 | 255.255.224.0 | 6 | 8190 |
| 4 | 255.255.240.0 | 14 | 4094 |
| 5 | 255.255.248.0 | 30 | 2046 |
| 6 | 255.255.252.0 | 62 | 1022 |
| 7 | 255.255.254.0 | 126 | 510 |
| 8 | 255.255.255.0 | 254 | 254 |
| 9 | 255.255.255.128 | 510 | 126 |
| 10 | 255.255.255.192 | 1022 | 62 |
| 11 | 255.255.255.224 | 2046 | 30 |
| 12 | 255.255.255.240 | 4096 | 14 |
| 13 | 255.255.255.248 | 8190 | 6 |
| 14 | 255.255.255.252 | 16382 | 2 |