OsbornePro LogoSubnet Calculator

This tool can be used to calculate subnet address ranges. You quickly and easily see how many total and usable IPv4 addresses are in the range you specify. The below tables can also be used to quickly reference IPv4 or IPv6 subnet information.



Define Values Here

IPv4 Address:
Enter an IPv4 Address here
Select Subnet Mask
Then select your subnet mask

View Results

Address Range:

Mask:

Total:

Usable:

CIDR:

Subnet Cheat Sheet

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.

IPv4 Subnetting Chart

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

IPv6 Subnet Cheat Sheet

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.

IPv6 Subnetting Chart

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