Complete CIDR notation reference chart with subnet masks, IP ranges, and network information.
🔢 Use CIDR Calculator| CIDR | Subnet Mask | Wildcard Mask | Total IPs | Usable IPs | Network Class |
|---|---|---|---|---|---|
| /8 | 255.0.0.0 | 0.255.255.255 | 16,777,216 | 16,777,214 | Class A |
| /9 | 255.128.0.0 | 0.127.255.255 | 8,388,608 | 8,388,606 | - |
| /10 | 255.192.0.0 | 0.63.255.255 | 4,194,304 | 4,194,302 | - |
| /11 | 255.224.0.0 | 0.31.255.255 | 2,097,152 | 2,097,150 | - |
| /12 | 255.240.0.0 | 0.15.255.255 | 1,048,576 | 1,048,574 | - |
| /13 | 255.248.0.0 | 0.7.255.255 | 524,288 | 524,286 | - |
| /14 | 255.252.0.0 | 0.3.255.255 | 262,144 | 262,142 | - |
| /15 | 255.254.0.0 | 0.1.255.255 | 131,072 | 131,070 | - |
| /16 | 255.255.0.0 | 0.0.255.255 | 65,536 | 65,534 | Class B |
| /17 | 255.255.128.0 | 0.0.127.255 | 32,768 | 32,766 | - |
| /18 | 255.255.192.0 | 0.0.63.255 | 16,384 | 16,382 | - |
| /19 | 255.255.224.0 | 0.0.31.255 | 8,192 | 8,190 | - |
| /20 | 255.255.240.0 | 0.0.15.255 | 4,096 | 4,094 | - |
| /21 | 255.255.248.0 | 0.0.7.255 | 2,048 | 2,046 | - |
| /22 | 255.255.252.0 | 0.0.3.255 | 1,024 | 1,022 | - |
| /23 | 255.255.254.0 | 0.0.1.255 | 512 | 510 | - |
| /24 | 255.255.255.0 | 0.0.0.255 | 256 | 254 | Class C |
| /25 | 255.255.255.128 | 0.0.0.127 | 128 | 126 | - |
| /26 | 255.255.255.192 | 0.0.0.63 | 64 | 62 | - |
| /27 | 255.255.255.224 | 0.0.0.31 | 32 | 30 | - |
| /28 | 255.255.255.240 | 0.0.0.15 | 16 | 14 | - |
| /29 | 255.255.255.248 | 0.0.0.7 | 8 | 6 | - |
| /30 | 255.255.255.252 | 0.0.0.3 | 4 | 2 | Point-to-Point |
| /31 | 255.255.255.254 | 0.0.0.1 | 2 | 2 | Point-to-Point |
| /32 | 255.255.255.255 | 0.0.0.0 | 1 | 1 | Host Route |