Use this tool to convert a Subnet Mask to CIDR notation


Select a Subnet Mask
CIDR Notation

Looking for a tool to convert CIDR to a Subnet Mask?

Subnet Mask Lookup Table

Subnet Mask

CIDR Prefix

Total IP Addresses

Usable IP Addresses

255.255.255.255

/32

1

1

255.255.255.254

/31

2

2*

255.255.255.252

/30

4

2

255.255.255.248

/29

8

6

255.255.255.240

/28

16

14

255.255.255.224

/27

32

30

255.255.255.192

/26

64

62

255.255.255.128

/25

128

126

255.255.255.0

/24

256

254

255.255.254.0

/23

512

510

255.255.252.0

/22

1024

1022

255.255.248.0

/21

2048

2046

255.255.240.0

/20

4096

4094

255.255.224.0

/19

8192

8190

255.255.192.0

/18

16,384

16,382

255.255.128.0

/17

32,768

32,766

255.255.0.0

/16

65,536

65,534

255.254.0.0

/15

131,072

131,070

255.252.0.0

/14

262,144

262,142

255.248.0.0

/13

524,288

524,286

255.240.0.0

/12

1,048,576

1,048,574

255.224.0.0

/11

2,097,152

2,097,150

255.192.0.0

/10

4,194,304

4,194,302

255.128.0.0

/9

8,388,608

8,388,606

255.0.0.0

/8

16,777,216

16,777,214

254.0.0.0

/7

33,554,432

33,554,430

252.0.0.0

/6

67,108,864

67,108,862

248.0.0.0

/5

134,217,728

134,217,726

240.0.0.0

/4

268,435,456

268,435,454

224.0.0.0

/3

536,870,912

536,870,910

192.0.0.0

/2

1,073,741,824

1,073,741,822

128.0.0.0

/1

2,147,483,648

2,147,483,646

0.0.0.0

/0

4,294,967,296

4,294,967,294