subnetting

Below is a table providing typical subnets for IPv4. 

   
Prefix size
   
Network mask
   
Usable hosts per subnet
  
/1
128.0.0.0
2,147,483,646
/2
192.0.0.0
1,073,741,822
/3
224.0.0.0
536,870,910
/4
240.0.0.0
268,435,454
/5
248.0.0.0
134,217,726
/6
252.0.0.0
67,108,862
/7
254.0.0.0
33,554,430
Class A
/8
255.0.0.0
16,777,214
/9
255.128.0.0
8,388,606
/10
255.192.0.0
4,194,302
/11
255.224.0.0
2,097,150
/12
255.240.0.0
1,048,574
/13
255.248.0.0
524,286
/14
255.252.0.0
262,142
/15
255.254.0.0
131,070
Class B
/16
255.255.0.0
65,534
/17
255.255.128.0
32,766
/18
255.255.192.0
16,382
/19
255.255.224.0
8,190
/20
255.255.240.0
4,094
/21
255.255.248.0
2,046
/22
255.255.252.0
1,022
/23
255.255.254.0
510
Class C
/24
255.255.255.0
254
/25
255.255.255.128
126
/26
255.255.255.192
62
/27
255.255.255.224
30
/28
255.255.255.240
14
/29
255.255.255.248
6
/30
255.255.255.252
2
/31
255.255.255.254
0
/32
255.255.255.255
0