Quick reference cheat sheet for daily subnetting tasks.
You can use the IPv4 chart for IP address planning and to convert subnet masks to CIDR and wildcards.
| CIDR | Subnet | # IP Addresses | # Usable IP Addresses | Wildcard |
|---|---|---|---|---|
| /32 | 255.255.255.255 | 1 | 1 | 0.0.0.0 |
| /31 | 255.255.255.254 | 2 | 2 (See RFC 3021) | 0.0.0.1 |
| /30 | 255.255.255.252 | 4 | 2 | 0.0.0.3 |
| /29 | 255.255.255.248 | 8 | 6 | 0.0.0.7 |
| /28 | 255.255.255.240 | 16 | 14 | 0.0.0.15 |
| /27 | 255.255.255.224 | 32 | 30 | 0.0.0.31 |
| /26 | 255.255.255.192 | 64 | 62 | 0.0.0.63 |
| /25 | 255.255.255.128 | 128 | 126 | 0.0.0.127 |
| /24 | 255.255.255.0 | 256 | 254 | 0.0.0.255 |
| /23 | 255.255.254.0 | 512 | 510 | 0.0.1.255 |
| /22 | 255.255.252.0 | 1024 | 1022 | 0.0.3.255 |
| /21 | 255.255.248.0 | 2048 | 2046 | 0.0.7.255 |
| /20 | 255.255.240.0 | 4096 | 4094 | 0.0.15.255 |
| /19 | 255.255.224.0 | 8192 | 8190 | 0.0.31.255 |
| /18 | 255.255.192.0 | 16,384 | 16,382 | 0.0.63.255 |
| /17 | 255.255.128.0 | 32,768 | 32,766 | 0.0.127.255 |
| /16 | 255.255.0.0 | 65,536 | 65,534 | 0.0.255.255 |
| /15 | 255.254.0.0 | 131,072 | 131,070 | 0.1.255.255 |
| /14 | 255.252.0.0 | 262,144 | 262,142 | 0.3.255.255 |
| /13 | 255.248.0.0 | 524,288 | 524,286 | 0.7.255.255 |
| /12 | 255.240.0.0 | 1,048,576 | 1,048,574 | 0.15.255.255 |
| /11 | 255.224.0.0 | 2,097,152 | 2,097,150 | 0.31.255.255 |
| /10 | 255.192.0.0 | 4,194,304 | 4,194,302 | 0.63.255.255 |
| /9 | 255.128.0.0 | 8,388,608 | 8,388,606 | 0.127.255.255 |
| /8 | 255.0.0.0 | 16,777,216 | 16,777,214 | 0.255.255.255 |
| /7 | 254.0.0.0 | 33,554,432 | 33,554,430 | 0.1.255.255 |
| /6 | 252.0.0.0 | 67,108,864 | 67,108,862 | 0.3.255.255 |
| /5 | 248.0.0.0 | 134,217,728 | 134,217,726 | 0.7.255.255 |
| /4 | 240.0.0.0 | 268,435,456 | 268,435,454 | 0.15.255.255 |
| /3 | 224.0.0.0 | 536,870,912 | 536,870,910 | 0.31.255.255 |
| /2 | 192.0.0.0 | 1,073,741,824 | 1,073,741,822 | 0.63.255.255 |
| /1 | 128.0.0.0 | 2,147,483,648 | 2,147,483,646 | 0.127.255.255 |
| /0 | 0.0.0.0 | 4,294,967,296 | 4,294,967,294 | 0.255.255.255 |
Quick reference cheat sheet for IPv6 subnetting tasks.
You can use the IPv6 chart for IP address planning and to convert subnet masks to CIDR.
| Prefix | Subnet Examples | Total IP Addresses | Number of /64 |
|---|---|---|---|
| 4 | x:: | 2 124 | 2 60 |
| 8 | xx:: | 2 120 | 2 56 |
| 12 | xxx:: | 2 116 | 2 52 |
| 16 | xxxx:: | 2 112 | 2 48 |
| 20 | xxxx:x:: | 2 108 | 2 44 |
| 24 | xxxx:xx:: | 2 104 | 2 40 |
| 28 | xxxx:xxx:: | 2 100 | 2 36 |
| 32 | xxxx:xxxx:: | 2 96 | 4,294,967,296 |
| 36 | xxxx:xxxx:x:: | 2 92 | 268,435,456 |
| 40 | xxxx:xxxx:xx:: | 2 88 | 16,777,216 |
| 44 | xxxx:xxxx:xxx:: | 2 84 | 1,048,576 |
| 48 | xxxx:xxxx:xxxx:: | 2 80 | 65,536 |
| 52 | xxxx:xxxx:xxxx:x:: | 2 76 | 4,096 |
| 56 | xxxx:xxxx:xxxx:xx:: | 2 72 | 256 |
| 60 | xxxx:xxxx:xxxx:xxx:: | 2 68 | 16 |
| 64 | xxxx:xxxx:xxxx:xxxx:: | 2 64 (18,446,744,073,709,551,616) | 1 |
| 68 | xxxx:xxxx:xxxx:xxxx:x:: | 2 60 (1,152,921,504,606,846,976) | 0 |
| 72 | xxxx:xxxx:xxxx:xxxx:xx:: | 2 56 (72,057,594,037,927,936) | 0 |
| 76 | xxxx:xxxx:xxxx:xxxx:xxx:: | 2 52 (4,503,599,627,370,496) | 0 |
| 80 | xxxx:xxxx:xxxx:xxxx:xxxx:: | 2 48 (281,474,976,710,656) | 0 |
| 84 | xxxx:xxxx:xxxx:xxxx:xxxx:x:: | 2 44 (17,592,186,044,416) | 0 |
| 88 | xxxx:xxxx:xxxx:xxxx:xxxx:xx:: | 2 40 (1,099,511,627,776) | 0 |
| 92 | xxxx:xxxx:xxxx:xxxx:xxxx:xxx:: | 2 36 (68,719,476,736) | 0 |
| 96 | xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:: | 2 32 (4,294,967,296) | 0 |
| 100 | xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:x:: | 2 28 (268,435,456) | 0 |
| 104 | xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xx:: | 2 24 (16,777,216) | 0 |
| 108 | xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxx:: | 2 20 (1,048,576) | 0 |
| 112 | xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:: | 2 16 (65,536) | 0 |
| 116 | xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:x:: | 2 12 (4,096) | 0 |
| 120 | xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xx:: | 2 8 (256) | 0 |
| 124 | xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxx:: | 2 4 (16) | 0 |
| 128 | xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx | 2 0 (1) | 0 |
