Usable Hosts
126
62
30
14
6
2
0
0
Subnets
2
4
8
16
32
64
128
256
4
2
Hosts
Binary totals, left to right
Binary
CIDR 4th Octet
CIDR 3rd Octet
CIDR 2nd Octet
CIDR 1st Octet
128
64
32
16
8
4
2
128
192
224
240
248
252
/25
/26
/27
/28
/29
/30
/31
2
128
2
64
2
32
2
16
2
8
2
4
2
2
20
1
/22
/23
/24
128
7
/17
64
6
/18
32
5
/19
16
4
/20
8
3
/21
2
254
0
1
1
/32
215
32,768
214
16,384
213
8,192
212
4,096
211
2,048
210
1,024
223
8,388,608
222
4,194,304
221
2,097,152
220
1,048,576
219
524,288
218
262,144
217
131,072
216
65,536
231
2,147,483,648
230
1,073,741,824
229
536,870,912
228
268,435,456
227
134,217,728
226
67,108,864
224
16,777,216
.0
.0
.0
.0
.0
.0
.4
.8
.12
.16
.20
.24
.28
.32
.36
.40
.44
.48
.52
.56
.60
.64
.68
.72
.76
.80
.84
.88
.92
.96
.100
.104
.108
.112
.116
.120
.124
.128
.132
.136
.140
.144
.48
.152
.156
.160
.164
.168
.172
.176
.180
.184
.188
.192
.196
.200
.204
.208
.212
.216
.220
.224
.228
.232
.236
.240
.244
.248
.252
225
33,554,432
.0
.2
.4
.6
.8
.10
.12
.14
.16
.18
.20
.22
.24
.26
.28
.30
.32
.34
.36
.38
.40
.42
.44
.46
.48
.50
.52
.54
.56
.58
.60
.62
.64
.66
.68
.70
.72
.74
.76
.78
.80
.82
.84
.86
.88
.90
.92
.94
.96
.98
.100
.102
.104
.106
.108
.110
.112
.114
.116
.118
.120
.122
.124
.126
.128
.130
.132
.134
.136
.138
.140
.142
.144
.146
.148
.150
.152
.154
.156
.158
.160
.162
.164
.166
.168
.170
.172
.174
.176
.178
.180
.182
.184
.186
.188
.190
.192
.194
.196
.198
.200
.202
.204
.206
.208
.210
.212
.214
.216
.218
.220
.222
.224
.226
.228
.230
/9
/1
/10
/2
/11
/3
/12
/4
/13
/5
.8
.16
.16
.24
.32
.32
.32
.40
.48
.48
.56
.64
.64
.64
.64
.72
.80
.80
.88
.96
.96
.96
.104
.112
.112
.120
.128
.128
.128
.128
.128
.136
.144
.144
.152
.160
.160
.160
.168
.176
.176
.184
.192
.192
.192
.192
.200
.208
.208
.216
.224
.224
.224
.232
.240
.240
.46
/14
/6
29
512
255
/15
/7
.232
.234
.236
.238
.240
.242
.244
.246
.248
.250
.252
.254
28
256
/16
/8