Subnet Cheat Sheet

This quick reference crib sheet made for day to day subnetting tasks.
You can use the IPv4 and IPv6 charts in network ip address planning and to convert subnet mask to cidr and wildcard.

IPv4 Subnetting Chart

CIDR Subnet # Addresses Wildcard
/32 255.255.255.255 1 0.0.0.0
/31 255.255.255.254 2 0.0.0.1
/30 255.255.255.252 4 0.0.0.3
/29 255.255.255.248 8 0.0.0.7
/28 255.255.255.240 16 0.0.0.15
/27 255.255.255.224 32 0.0.0.31
/26 255.255.255.192 64 0.0.0.63
/25 255.255.255.128 128 0.0.0.127
/24 255.255.255.0 256 0.0.0.255
/23 255.255.254.0 512 0.0.1.255
/22 255.255.252.0 1024 0.0.3.255
/21 255.255.248.0 2048 0.0.7.255
/20 255.255.240.0 4096 0.0.15.255
/19 255.255.224.0 8192 0.0.31.255
/18 255.255.192.0 16,384 0.0.63.255
/17 255.255.128.0 32,768 0.0.127.255
/16 255.255.0.0 65,536 0.0.255.255
/15 255.254.0.0 131,072 0.1.255.255
/14 255.252.0.0 262,144 0.3.255.255
/13 255.248.0.0 524,288 0.7.255.255
/12 255.240.0.0 1,048,576 0.15.255.255
/11 255.224.0.0 2,097,152 0.31.255.255
/10 255.192.0.0 4,194,304 0.63.255.255
/9 255.128.0.0 8,388,608 0.127.255.255
/8 255.0.0.0 16,777,216 0.255.255.255

IPv6 Subnet Chart

Prefix /48 /56 /64 /127 # Addresses
/24 16M 4G 1T 8388608Y 16777216Y
/25 8M 2G 512G 4194304Y 8388608Y
/26 4M 1G 256G 2097152Y 4194304Y
/27 2M 512M 128G 1048576Y 2097152Y
/28 1M 256M 64G 524288Y 1048576Y
/29 512K 128M 32G 262144Y 524288Y
/30 256K 64M 16G 131072Y 262144Y
/31 128K 32M 8G 65536Y 131072Y
/32 64K 16M 4G 32768Y 65536Y
/33 32K 8M 2G 16384Y 32768Y
/34 16K 4M 1G 8192Y 16384Y
/35 8K 2M 512M 4096Y 8192Y
/36 4K 1M 256M 2048Y 4096Y
/37 2K 512K 128M 1024Y 2048Y
/38 1K 256K 64M 512Y 1024Y
/39 512 128K 32M 256Y 512Y
/40 256 64K 16M 128Y 256Y
/41 128 32K 8M 64Y 128Y
/42 64 16K 4M 32Y 64Y
/43 32 8K 2M 16Y 32Y
/44 16 4K 1M 8Y 16Y
/45 8 2K 512K 4Y 8Y
/46 4 1K 256K 2Y 4Y
/47 2 512 128K 1Y 2Y
/48 1 256 64K 512Z 1Y
/49 128 32K 256Z 512Z
/50 64 16K 128Z 256Z
/51 32 8K 64Z 128Z
/52 16 4K 32Z 64Z
/53 8 2K 16Z 32Z
/54 4 1K 8Z 16Z
/55 2 512 4Z 8Z
/56 1 256 2Z 4Z
/57 128 1Z 2Z
/58 64 512E 1Z
/59 32 256E 512E
/60 16 128E 256E
/61 8 64E 128E
/62 4 32E 64E
/63 2 16E 32E
/64 1 8E 16E

The subnet mask cheat sheet units is based on IEC 60027-2: Y = 1,208,925,819,614,629,174,706,176; Z = 1,180,591,620,717,411,303,424; E = 1,152,921,504,606,846,976; T = 1,099,511,627,776; G = 1,073,741,824; M = 1,048,576; K = 1,024

cheat sheet Cloud