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IP subnet calculator

Type an address with its prefix or mask to see the network, its usable range and masks. Split it into smaller subnets, or look up any prefix in the reference tables.

Network138.52.0.0/17
Usable hosts32,766
Subnet mask255.255.128.0
Addresses32,768
Network address
138.52.0.0
Broadcast address
138.52.127.255
First usable
138.52.0.1
Last usable
138.52.127.254
Usable hosts
32,766 (32,768 less the network and broadcast addresses)
Subnet mask
255.255.128.0
Wildcard mask
0.0.127.255 (Cisco ACLs, OSPF)
Prefix length
/17
Type
Public public
Old class
B (default /16)
As numbers
Hex 8A340000 · Integer 2318663680 to 2318696447
Reverse DNS zones
0.52.138.in-addr.arpa
1.52.138.in-addr.arpa
2.52.138.in-addr.arpa
3.52.138.in-addr.arpa
4.52.138.in-addr.arpa
5.52.138.in-addr.arpa
6.52.138.in-addr.arpa
7.52.138.in-addr.arpa
8.52.138.in-addr.arpa
9.52.138.in-addr.arpa
10.52.138.in-addr.arpa
11.52.138.in-addr.arpa
12.52.138.in-addr.arpa
13.52.138.in-addr.arpa
14.52.138.in-addr.arpa
15.52.138.in-addr.arpa
and 112 more
/17 is not on a 8-bit boundary, so it takes 128 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10001010.00110100.00000000.00000000138.52.0.0
Subnet mask11111111.11111111.10000000.00000000255.255.128.0
Network10001010.00110100.00000000.00000000138.52.0.0
Broadcast10001010.00110100.01111111.11111111138.52.127.255
Split into smaller subnets/27
/18 (2)/19 (4)/20 (8)/21 (16)/22 (32)/23 (64)/24 (128)/25 (256)/26 (512)/27 (1,024)/28 (2,048)/29 (4,096)

138.52.0.0/17 makes 1,024 subnets of /27; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1138.52.0.0/27138.52.0.1 to 138.52.0.30138.52.0.3130
2138.52.0.32/27138.52.0.33 to 138.52.0.62138.52.0.6330
3138.52.0.64/27138.52.0.65 to 138.52.0.94138.52.0.9530
4138.52.0.96/27138.52.0.97 to 138.52.0.126138.52.0.12730
5138.52.0.128/27138.52.0.129 to 138.52.0.158138.52.0.15930
6138.52.0.160/27138.52.0.161 to 138.52.0.190138.52.0.19130
7138.52.0.192/27138.52.0.193 to 138.52.0.222138.52.0.22330
8138.52.0.224/27138.52.0.225 to 138.52.0.254138.52.0.25530
9138.52.1.0/27138.52.1.1 to 138.52.1.30138.52.1.3130
10138.52.1.32/27138.52.1.33 to 138.52.1.62138.52.1.6330
11138.52.1.64/27138.52.1.65 to 138.52.1.94138.52.1.9530
12138.52.1.96/27138.52.1.97 to 138.52.1.126138.52.1.12730
13138.52.1.128/27138.52.1.129 to 138.52.1.158138.52.1.15930
14138.52.1.160/27138.52.1.161 to 138.52.1.190138.52.1.19130
15138.52.1.192/27138.52.1.193 to 138.52.1.222138.52.1.22330
16138.52.1.224/27138.52.1.225 to 138.52.1.254138.52.1.25530
17138.52.2.0/27138.52.2.1 to 138.52.2.30138.52.2.3130
18138.52.2.32/27138.52.2.33 to 138.52.2.62138.52.2.6330
19138.52.2.64/27138.52.2.65 to 138.52.2.94138.52.2.9530
20138.52.2.96/27138.52.2.97 to 138.52.2.126138.52.2.12730
21138.52.2.128/27138.52.2.129 to 138.52.2.158138.52.2.15930
22138.52.2.160/27138.52.2.161 to 138.52.2.190138.52.2.19130
23138.52.2.192/27138.52.2.193 to 138.52.2.222138.52.2.22330
24138.52.2.224/27138.52.2.225 to 138.52.2.254138.52.2.25530
25138.52.3.0/27138.52.3.1 to 138.52.3.30138.52.3.3130
26138.52.3.32/27138.52.3.33 to 138.52.3.62138.52.3.6330
27138.52.3.64/27138.52.3.65 to 138.52.3.94138.52.3.9530
28138.52.3.96/27138.52.3.97 to 138.52.3.126138.52.3.12730
29138.52.3.128/27138.52.3.129 to 138.52.3.158138.52.3.15930
30138.52.3.160/27138.52.3.161 to 138.52.3.190138.52.3.19130
31138.52.3.192/27138.52.3.193 to 138.52.3.222138.52.3.22330
32138.52.3.224/27138.52.3.225 to 138.52.3.254138.52.3.25530
33138.52.4.0/27138.52.4.1 to 138.52.4.30138.52.4.3130
34138.52.4.32/27138.52.4.33 to 138.52.4.62138.52.4.6330
35138.52.4.64/27138.52.4.65 to 138.52.4.94138.52.4.9530
36138.52.4.96/27138.52.4.97 to 138.52.4.126138.52.4.12730
37138.52.4.128/27138.52.4.129 to 138.52.4.158138.52.4.15930
38138.52.4.160/27138.52.4.161 to 138.52.4.190138.52.4.19130
39138.52.4.192/27138.52.4.193 to 138.52.4.222138.52.4.22330
40138.52.4.224/27138.52.4.225 to 138.52.4.254138.52.4.25530
41138.52.5.0/27138.52.5.1 to 138.52.5.30138.52.5.3130
42138.52.5.32/27138.52.5.33 to 138.52.5.62138.52.5.6330
43138.52.5.64/27138.52.5.65 to 138.52.5.94138.52.5.9530
44138.52.5.96/27138.52.5.97 to 138.52.5.126138.52.5.12730
45138.52.5.128/27138.52.5.129 to 138.52.5.158138.52.5.15930
46138.52.5.160/27138.52.5.161 to 138.52.5.190138.52.5.19130
47138.52.5.192/27138.52.5.193 to 138.52.5.222138.52.5.22330
48138.52.5.224/27138.52.5.225 to 138.52.5.254138.52.5.25530
49138.52.6.0/27138.52.6.1 to 138.52.6.30138.52.6.3130
50138.52.6.32/27138.52.6.33 to 138.52.6.62138.52.6.6330
51138.52.6.64/27138.52.6.65 to 138.52.6.94138.52.6.9530
52138.52.6.96/27138.52.6.97 to 138.52.6.126138.52.6.12730
53138.52.6.128/27138.52.6.129 to 138.52.6.158138.52.6.15930
54138.52.6.160/27138.52.6.161 to 138.52.6.190138.52.6.19130
55138.52.6.192/27138.52.6.193 to 138.52.6.222138.52.6.22330
56138.52.6.224/27138.52.6.225 to 138.52.6.254138.52.6.25530
57138.52.7.0/27138.52.7.1 to 138.52.7.30138.52.7.3130
58138.52.7.32/27138.52.7.33 to 138.52.7.62138.52.7.6330
59138.52.7.64/27138.52.7.65 to 138.52.7.94138.52.7.9530
60138.52.7.96/27138.52.7.97 to 138.52.7.126138.52.7.12730
61138.52.7.128/27138.52.7.129 to 138.52.7.158138.52.7.15930
62138.52.7.160/27138.52.7.161 to 138.52.7.190138.52.7.19130
63138.52.7.192/27138.52.7.193 to 138.52.7.222138.52.7.22330
64138.52.7.224/27138.52.7.225 to 138.52.7.254138.52.7.25530
65138.52.8.0/27138.52.8.1 to 138.52.8.30138.52.8.3130
66138.52.8.32/27138.52.8.33 to 138.52.8.62138.52.8.6330
67138.52.8.64/27138.52.8.65 to 138.52.8.94138.52.8.9530
68138.52.8.96/27138.52.8.97 to 138.52.8.126138.52.8.12730
69138.52.8.128/27138.52.8.129 to 138.52.8.158138.52.8.15930
70138.52.8.160/27138.52.8.161 to 138.52.8.190138.52.8.19130
71138.52.8.192/27138.52.8.193 to 138.52.8.222138.52.8.22330
72138.52.8.224/27138.52.8.225 to 138.52.8.254138.52.8.25530
73138.52.9.0/27138.52.9.1 to 138.52.9.30138.52.9.3130
74138.52.9.32/27138.52.9.33 to 138.52.9.62138.52.9.6330
75138.52.9.64/27138.52.9.65 to 138.52.9.94138.52.9.9530
76138.52.9.96/27138.52.9.97 to 138.52.9.126138.52.9.12730
77138.52.9.128/27138.52.9.129 to 138.52.9.158138.52.9.15930
78138.52.9.160/27138.52.9.161 to 138.52.9.190138.52.9.19130
79138.52.9.192/27138.52.9.193 to 138.52.9.222138.52.9.22330
80138.52.9.224/27138.52.9.225 to 138.52.9.254138.52.9.25530
81138.52.10.0/27138.52.10.1 to 138.52.10.30138.52.10.3130
82138.52.10.32/27138.52.10.33 to 138.52.10.62138.52.10.6330
83138.52.10.64/27138.52.10.65 to 138.52.10.94138.52.10.9530
84138.52.10.96/27138.52.10.97 to 138.52.10.126138.52.10.12730
85138.52.10.128/27138.52.10.129 to 138.52.10.158138.52.10.15930
86138.52.10.160/27138.52.10.161 to 138.52.10.190138.52.10.19130
87138.52.10.192/27138.52.10.193 to 138.52.10.222138.52.10.22330
88138.52.10.224/27138.52.10.225 to 138.52.10.254138.52.10.25530
89138.52.11.0/27138.52.11.1 to 138.52.11.30138.52.11.3130
90138.52.11.32/27138.52.11.33 to 138.52.11.62138.52.11.6330
91138.52.11.64/27138.52.11.65 to 138.52.11.94138.52.11.9530
92138.52.11.96/27138.52.11.97 to 138.52.11.126138.52.11.12730
93138.52.11.128/27138.52.11.129 to 138.52.11.158138.52.11.15930
94138.52.11.160/27138.52.11.161 to 138.52.11.190138.52.11.19130
95138.52.11.192/27138.52.11.193 to 138.52.11.222138.52.11.22330
96138.52.11.224/27138.52.11.225 to 138.52.11.254138.52.11.25530
97138.52.12.0/27138.52.12.1 to 138.52.12.30138.52.12.3130
98138.52.12.32/27138.52.12.33 to 138.52.12.62138.52.12.6330
99138.52.12.64/27138.52.12.65 to 138.52.12.94138.52.12.9530
100138.52.12.96/27138.52.12.97 to 138.52.12.126138.52.12.12730
101138.52.12.128/27138.52.12.129 to 138.52.12.158138.52.12.15930
102138.52.12.160/27138.52.12.161 to 138.52.12.190138.52.12.19130
103138.52.12.192/27138.52.12.193 to 138.52.12.222138.52.12.22330
104138.52.12.224/27138.52.12.225 to 138.52.12.254138.52.12.25530
105138.52.13.0/27138.52.13.1 to 138.52.13.30138.52.13.3130
106138.52.13.32/27138.52.13.33 to 138.52.13.62138.52.13.6330
107138.52.13.64/27138.52.13.65 to 138.52.13.94138.52.13.9530
108138.52.13.96/27138.52.13.97 to 138.52.13.126138.52.13.12730
109138.52.13.128/27138.52.13.129 to 138.52.13.158138.52.13.15930
110138.52.13.160/27138.52.13.161 to 138.52.13.190138.52.13.19130
111138.52.13.192/27138.52.13.193 to 138.52.13.222138.52.13.22330
112138.52.13.224/27138.52.13.225 to 138.52.13.254138.52.13.25530
113138.52.14.0/27138.52.14.1 to 138.52.14.30138.52.14.3130
114138.52.14.32/27138.52.14.33 to 138.52.14.62138.52.14.6330
115138.52.14.64/27138.52.14.65 to 138.52.14.94138.52.14.9530
116138.52.14.96/27138.52.14.97 to 138.52.14.126138.52.14.12730
117138.52.14.128/27138.52.14.129 to 138.52.14.158138.52.14.15930
118138.52.14.160/27138.52.14.161 to 138.52.14.190138.52.14.19130
119138.52.14.192/27138.52.14.193 to 138.52.14.222138.52.14.22330
120138.52.14.224/27138.52.14.225 to 138.52.14.254138.52.14.25530
121138.52.15.0/27138.52.15.1 to 138.52.15.30138.52.15.3130
122138.52.15.32/27138.52.15.33 to 138.52.15.62138.52.15.6330
123138.52.15.64/27138.52.15.65 to 138.52.15.94138.52.15.9530
124138.52.15.96/27138.52.15.97 to 138.52.15.126138.52.15.12730
125138.52.15.128/27138.52.15.129 to 138.52.15.158138.52.15.15930
126138.52.15.160/27138.52.15.161 to 138.52.15.190138.52.15.19130
127138.52.15.192/27138.52.15.193 to 138.52.15.222138.52.15.22330
128138.52.15.224/27138.52.15.225 to 138.52.15.254138.52.15.25530
129138.52.16.0/27138.52.16.1 to 138.52.16.30138.52.16.3130
130138.52.16.32/27138.52.16.33 to 138.52.16.62138.52.16.6330
131138.52.16.64/27138.52.16.65 to 138.52.16.94138.52.16.9530
132138.52.16.96/27138.52.16.97 to 138.52.16.126138.52.16.12730
133138.52.16.128/27138.52.16.129 to 138.52.16.158138.52.16.15930
134138.52.16.160/27138.52.16.161 to 138.52.16.190138.52.16.19130
135138.52.16.192/27138.52.16.193 to 138.52.16.222138.52.16.22330
136138.52.16.224/27138.52.16.225 to 138.52.16.254138.52.16.25530
137138.52.17.0/27138.52.17.1 to 138.52.17.30138.52.17.3130
138138.52.17.32/27138.52.17.33 to 138.52.17.62138.52.17.6330
139138.52.17.64/27138.52.17.65 to 138.52.17.94138.52.17.9530
140138.52.17.96/27138.52.17.97 to 138.52.17.126138.52.17.12730
141138.52.17.128/27138.52.17.129 to 138.52.17.158138.52.17.15930
142138.52.17.160/27138.52.17.161 to 138.52.17.190138.52.17.19130
143138.52.17.192/27138.52.17.193 to 138.52.17.222138.52.17.22330
144138.52.17.224/27138.52.17.225 to 138.52.17.254138.52.17.25530
145138.52.18.0/27138.52.18.1 to 138.52.18.30138.52.18.3130
146138.52.18.32/27138.52.18.33 to 138.52.18.62138.52.18.6330
147138.52.18.64/27138.52.18.65 to 138.52.18.94138.52.18.9530
148138.52.18.96/27138.52.18.97 to 138.52.18.126138.52.18.12730
149138.52.18.128/27138.52.18.129 to 138.52.18.158138.52.18.15930
150138.52.18.160/27138.52.18.161 to 138.52.18.190138.52.18.19130
151138.52.18.192/27138.52.18.193 to 138.52.18.222138.52.18.22330
152138.52.18.224/27138.52.18.225 to 138.52.18.254138.52.18.25530
153138.52.19.0/27138.52.19.1 to 138.52.19.30138.52.19.3130
154138.52.19.32/27138.52.19.33 to 138.52.19.62138.52.19.6330
155138.52.19.64/27138.52.19.65 to 138.52.19.94138.52.19.9530
156138.52.19.96/27138.52.19.97 to 138.52.19.126138.52.19.12730
157138.52.19.128/27138.52.19.129 to 138.52.19.158138.52.19.15930
158138.52.19.160/27138.52.19.161 to 138.52.19.190138.52.19.19130
159138.52.19.192/27138.52.19.193 to 138.52.19.222138.52.19.22330
160138.52.19.224/27138.52.19.225 to 138.52.19.254138.52.19.25530
161138.52.20.0/27138.52.20.1 to 138.52.20.30138.52.20.3130
162138.52.20.32/27138.52.20.33 to 138.52.20.62138.52.20.6330
163138.52.20.64/27138.52.20.65 to 138.52.20.94138.52.20.9530
164138.52.20.96/27138.52.20.97 to 138.52.20.126138.52.20.12730
165138.52.20.128/27138.52.20.129 to 138.52.20.158138.52.20.15930
166138.52.20.160/27138.52.20.161 to 138.52.20.190138.52.20.19130
167138.52.20.192/27138.52.20.193 to 138.52.20.222138.52.20.22330
168138.52.20.224/27138.52.20.225 to 138.52.20.254138.52.20.25530
169138.52.21.0/27138.52.21.1 to 138.52.21.30138.52.21.3130
170138.52.21.32/27138.52.21.33 to 138.52.21.62138.52.21.6330
171138.52.21.64/27138.52.21.65 to 138.52.21.94138.52.21.9530
172138.52.21.96/27138.52.21.97 to 138.52.21.126138.52.21.12730
173138.52.21.128/27138.52.21.129 to 138.52.21.158138.52.21.15930
174138.52.21.160/27138.52.21.161 to 138.52.21.190138.52.21.19130
175138.52.21.192/27138.52.21.193 to 138.52.21.222138.52.21.22330
176138.52.21.224/27138.52.21.225 to 138.52.21.254138.52.21.25530
177138.52.22.0/27138.52.22.1 to 138.52.22.30138.52.22.3130
178138.52.22.32/27138.52.22.33 to 138.52.22.62138.52.22.6330
179138.52.22.64/27138.52.22.65 to 138.52.22.94138.52.22.9530
180138.52.22.96/27138.52.22.97 to 138.52.22.126138.52.22.12730
181138.52.22.128/27138.52.22.129 to 138.52.22.158138.52.22.15930
182138.52.22.160/27138.52.22.161 to 138.52.22.190138.52.22.19130
183138.52.22.192/27138.52.22.193 to 138.52.22.222138.52.22.22330
184138.52.22.224/27138.52.22.225 to 138.52.22.254138.52.22.25530
185138.52.23.0/27138.52.23.1 to 138.52.23.30138.52.23.3130
186138.52.23.32/27138.52.23.33 to 138.52.23.62138.52.23.6330
187138.52.23.64/27138.52.23.65 to 138.52.23.94138.52.23.9530
188138.52.23.96/27138.52.23.97 to 138.52.23.126138.52.23.12730
189138.52.23.128/27138.52.23.129 to 138.52.23.158138.52.23.15930
190138.52.23.160/27138.52.23.161 to 138.52.23.190138.52.23.19130
191138.52.23.192/27138.52.23.193 to 138.52.23.222138.52.23.22330
192138.52.23.224/27138.52.23.225 to 138.52.23.254138.52.23.25530
193138.52.24.0/27138.52.24.1 to 138.52.24.30138.52.24.3130
194138.52.24.32/27138.52.24.33 to 138.52.24.62138.52.24.6330
195138.52.24.64/27138.52.24.65 to 138.52.24.94138.52.24.9530
196138.52.24.96/27138.52.24.97 to 138.52.24.126138.52.24.12730
197138.52.24.128/27138.52.24.129 to 138.52.24.158138.52.24.15930
198138.52.24.160/27138.52.24.161 to 138.52.24.190138.52.24.19130
199138.52.24.192/27138.52.24.193 to 138.52.24.222138.52.24.22330
200138.52.24.224/27138.52.24.225 to 138.52.24.254138.52.24.25530
201138.52.25.0/27138.52.25.1 to 138.52.25.30138.52.25.3130
202138.52.25.32/27138.52.25.33 to 138.52.25.62138.52.25.6330
203138.52.25.64/27138.52.25.65 to 138.52.25.94138.52.25.9530
204138.52.25.96/27138.52.25.97 to 138.52.25.126138.52.25.12730
205138.52.25.128/27138.52.25.129 to 138.52.25.158138.52.25.15930
206138.52.25.160/27138.52.25.161 to 138.52.25.190138.52.25.19130
207138.52.25.192/27138.52.25.193 to 138.52.25.222138.52.25.22330
208138.52.25.224/27138.52.25.225 to 138.52.25.254138.52.25.25530
209138.52.26.0/27138.52.26.1 to 138.52.26.30138.52.26.3130
210138.52.26.32/27138.52.26.33 to 138.52.26.62138.52.26.6330
211138.52.26.64/27138.52.26.65 to 138.52.26.94138.52.26.9530
212138.52.26.96/27138.52.26.97 to 138.52.26.126138.52.26.12730
213138.52.26.128/27138.52.26.129 to 138.52.26.158138.52.26.15930
214138.52.26.160/27138.52.26.161 to 138.52.26.190138.52.26.19130
215138.52.26.192/27138.52.26.193 to 138.52.26.222138.52.26.22330
216138.52.26.224/27138.52.26.225 to 138.52.26.254138.52.26.25530
217138.52.27.0/27138.52.27.1 to 138.52.27.30138.52.27.3130
218138.52.27.32/27138.52.27.33 to 138.52.27.62138.52.27.6330
219138.52.27.64/27138.52.27.65 to 138.52.27.94138.52.27.9530
220138.52.27.96/27138.52.27.97 to 138.52.27.126138.52.27.12730
221138.52.27.128/27138.52.27.129 to 138.52.27.158138.52.27.15930
222138.52.27.160/27138.52.27.161 to 138.52.27.190138.52.27.19130
223138.52.27.192/27138.52.27.193 to 138.52.27.222138.52.27.22330
224138.52.27.224/27138.52.27.225 to 138.52.27.254138.52.27.25530
225138.52.28.0/27138.52.28.1 to 138.52.28.30138.52.28.3130
226138.52.28.32/27138.52.28.33 to 138.52.28.62138.52.28.6330
227138.52.28.64/27138.52.28.65 to 138.52.28.94138.52.28.9530
228138.52.28.96/27138.52.28.97 to 138.52.28.126138.52.28.12730
229138.52.28.128/27138.52.28.129 to 138.52.28.158138.52.28.15930
230138.52.28.160/27138.52.28.161 to 138.52.28.190138.52.28.19130
231138.52.28.192/27138.52.28.193 to 138.52.28.222138.52.28.22330
232138.52.28.224/27138.52.28.225 to 138.52.28.254138.52.28.25530
233138.52.29.0/27138.52.29.1 to 138.52.29.30138.52.29.3130
234138.52.29.32/27138.52.29.33 to 138.52.29.62138.52.29.6330
235138.52.29.64/27138.52.29.65 to 138.52.29.94138.52.29.9530
236138.52.29.96/27138.52.29.97 to 138.52.29.126138.52.29.12730
237138.52.29.128/27138.52.29.129 to 138.52.29.158138.52.29.15930
238138.52.29.160/27138.52.29.161 to 138.52.29.190138.52.29.19130
239138.52.29.192/27138.52.29.193 to 138.52.29.222138.52.29.22330
240138.52.29.224/27138.52.29.225 to 138.52.29.254138.52.29.25530
241138.52.30.0/27138.52.30.1 to 138.52.30.30138.52.30.3130
242138.52.30.32/27138.52.30.33 to 138.52.30.62138.52.30.6330
243138.52.30.64/27138.52.30.65 to 138.52.30.94138.52.30.9530
244138.52.30.96/27138.52.30.97 to 138.52.30.126138.52.30.12730
245138.52.30.128/27138.52.30.129 to 138.52.30.158138.52.30.15930
246138.52.30.160/27138.52.30.161 to 138.52.30.190138.52.30.19130
247138.52.30.192/27138.52.30.193 to 138.52.30.222138.52.30.22330
248138.52.30.224/27138.52.30.225 to 138.52.30.254138.52.30.25530
249138.52.31.0/27138.52.31.1 to 138.52.31.30138.52.31.3130
250138.52.31.32/27138.52.31.33 to 138.52.31.62138.52.31.6330
251138.52.31.64/27138.52.31.65 to 138.52.31.94138.52.31.9530
252138.52.31.96/27138.52.31.97 to 138.52.31.126138.52.31.12730
253138.52.31.128/27138.52.31.129 to 138.52.31.158138.52.31.15930
254138.52.31.160/27138.52.31.161 to 138.52.31.190138.52.31.19130
255138.52.31.192/27138.52.31.193 to 138.52.31.222138.52.31.22330
256138.52.31.224/27138.52.31.225 to 138.52.31.254138.52.31.25530

IPv4 CIDR reference (/0 to /32)

IPv4 prefix lengths
PrefixSubnet maskWildcardAddressesUsable hostsSizeTypical use
/00.0.0.0255.255.255.2554,294,967,2964,294,967,29416,777,216 × /24
/1128.0.0.0127.255.255.2552,147,483,6482,147,483,6468,388,608 × /24
/2192.0.0.063.255.255.2551,073,741,8241,073,741,8224,194,304 × /24
/3224.0.0.031.255.255.255536,870,912536,870,9102,097,152 × /24
/4240.0.0.015.255.255.255268,435,456268,435,4541,048,576 × /24
/5248.0.0.07.255.255.255134,217,728134,217,726524,288 × /24
/6252.0.0.03.255.255.25567,108,86467,108,862262,144 × /24
/7254.0.0.01.255.255.25533,554,43233,554,430131,072 × /24
/8255.0.0.00.255.255.25516,777,21616,777,21465,536 × /24Old class A; 10.0.0.0/8
/9255.128.0.00.127.255.2558,388,6088,388,60632,768 × /24
/10255.192.0.00.63.255.2554,194,3044,194,30216,384 × /24
/11255.224.0.00.31.255.2552,097,1522,097,1508,192 × /24
/12255.240.0.00.15.255.2551,048,5761,048,5744,096 × /24172.16.0.0/12
/13255.248.0.00.7.255.255524,288524,2862,048 × /24
/14255.252.0.00.3.255.255262,144262,1421,024 × /24
/15255.254.0.00.1.255.255131,072131,070512 × /24
/16255.255.0.00.0.255.25565,53665,534256 × /24Old class B; 192.168.0.0/16
/17255.255.128.00.0.127.25532,76832,766128 × /24
/18255.255.192.00.0.63.25516,38416,38264 × /24
/19255.255.224.00.0.31.2558,1928,19032 × /24
/20255.255.240.00.0.15.2554,0964,09416 × /24
/21255.255.248.00.0.7.2552,0482,0468 × /24
/22255.255.252.00.0.3.2551,0241,0224 × /24Large office or guest Wi-Fi (1,022 hosts)
/23255.255.254.00.0.1.2555125102 × /24Larger office LAN (510 hosts)
/24255.255.255.00.0.0.2552562541 × /24Typical office LAN (old class C)
/25255.255.255.1280.0.0.1271281261/2 of a /24Smaller LAN or VLAN
/26255.255.255.1920.0.0.6364621/4 of a /24Smaller LAN or VLAN
/27255.255.255.2240.0.0.3132301/8 of a /24Small VLAN, phones, cameras
/28255.255.255.2400.0.0.1516141/16 of a /24Small VLAN, phones, cameras
/29255.255.255.2480.0.0.7861/32 of a /24Small fixed public block (5 usable)
/30255.255.255.2520.0.0.3421/64 of a /24Point-to-point (old style)
/31255.255.255.2540.0.0.1221/128 of a /24Point-to-point link (RFC 3021)
/32255.255.255.2550.0.0.0111/256 of a /24One host

IPv6 prefix reference

IPv6 prefix lengths
PrefixAddresses/64 LANs/48 sitesNibbleTypical use
/342,535,295,865,117,307,932,921,825,928,971,026,432 (2^125)2,305,843,009,213,693,95235,184,372,088,832NoAll global unicast (2000::/3)
/165,192,296,858,534,827,628,530,496,329,220,096 (2^112)281,474,976,710,6564,294,967,296Yes
/20324,518,553,658,426,726,783,156,020,576,256 (2^108)17,592,186,044,416268,435,456YesLarge provider allocation (RIPE minimum for some)
/29633,825,300,114,114,700,748,351,602,688 (2^99)34,359,738,368524,288NoRIPE allocation to a provider (often)
/3279,228,162,514,264,337,593,543,950,336 (2^96)4,294,967,29665,536YesProvider allocation (RIPE default)
/364,951,760,157,141,521,099,596,496,896 (2^92)268,435,4564,096Yes
/40309,485,009,821,345,068,724,781,056 (2^88)16,777,216256Yes
/4419,342,813,113,834,066,795,298,816 (2^84)1,048,57616Yes
/481,208,925,819,614,629,174,706,176 (2^80)65,5361YesOne site or organisation (RIPE PI / assignment)
/5275,557,863,725,914,323,419,136 (2^76)4,096Yes
/564,722,366,482,869,645,213,696 (2^72)256YesSmall site or home (common provider assignment)
/60295,147,905,179,352,825,856 (2^68)16YesSome home broadband (16 LANs)
/6418,446,744,073,709,551,616 (2^64)1YesOne LAN or VLAN (needed for SLAAC)
/7272,057,594,037,927,936 (2^56)1/256 of a /64Yes
/80281,474,976,710,656 (2^48)1/65,536 of a /64Yes
/964,294,967,2961/4,294,967,296 of a /64YesEmbeds an IPv4 address (NAT64)
/11265,5361/281,474,976,710,656 of a /64Yes
/1202561/72,057,594,037,927,936 of a /64Yes
/124161/1,152,921,504,606,846,976 of a /64Yes
/12641/4,611,686,018,427,387,904 of a /64No
/12721/9,223,372,036,854,775,808 of a /64NoPoint-to-point link (RFC 6164)
/12811/18,446,744,073,709,551,616 of a /64YesOne host or loopback

Private and special ranges

IPv4

Special-purpose ranges
RangeNameWhat it is
255.255.255.255/32Limited broadcastEvery host on the local network
0.0.0.0/8This networkNot routed; 0.0.0.0 means "any address" in settings
10.0.0.0/8Private (RFC 1918)Office and home networks; not routed on the internet
100.64.0.0/10Shared address space (CGNAT)Used by providers behind carrier-grade NAT (RFC 6598)
127.0.0.0/8LoopbackThis computer
169.254.0.0/16Link-local (APIPA)Self-assigned when no DHCP server answers
172.16.0.0/12Private (RFC 1918)Office and home networks; not routed on the internet
192.0.0.0/24IETF protocol assignmentsSpecial uses such as DS-Lite
192.0.2.0/24Documentation (TEST-NET-1)For examples; never used on a network
192.88.99.0/246to4 relay (deprecated)Formerly anycast for 6to4
192.168.0.0/16Private (RFC 1918)Office and home networks; not routed on the internet
198.18.0.0/15BenchmarkingNetwork equipment testing (RFC 2544)
198.51.100.0/24Documentation (TEST-NET-2)For examples; never used on a network
203.0.113.0/24Documentation (TEST-NET-3)For examples; never used on a network
224.0.0.0/4MulticastOne-to-many traffic, such as IPTV and routing protocols
240.0.0.0/4ReservedFuture use; not usable on most systems

IPv6

Special-purpose ranges
RangeNameWhat it is
::/128UnspecifiedNo address; :: means "any address" in settings
::1/128LoopbackThis computer
::ffff:0:0/96IPv4-mappedAn IPv4 address written as IPv6
64:ff9b::/96NAT64IPv4 addresses reached through a NAT64 gateway
100::/64Discard onlyTraffic sent here is dropped (RFC 6666)
2001:db8::/32DocumentationFor examples; never used on a network
2001::/32TeredoIPv6 tunnelled over IPv4 UDP
2002::/166to4IPv6 tunnelled over IPv4 (largely retired)
3fff::/20DocumentationFor examples (RFC 9637)
fc00::/7Unique local (ULA)Private IPv6, like RFC 1918; usually fd00::/8
fe80::/10Link-localEvery IPv6 interface has one; not routed
ff00::/8MulticastOne-to-many traffic; replaces broadcast
2000::/3Global unicastPublic internet addresses

About this tool

A network is written as an address and a prefix length, such as 192.168.1.0/24: the first 24 bits name the network and the rest number the devices on it. The calculator works out where the network starts and ends, how many devices it holds, its subnet and wildcard masks, and the reverse DNS zone to ask your provider for.

It also splits a network into equal smaller ones (one per VLAN or site), turns a range of addresses into the fewest CIDR blocks for a firewall rule, and lists every IPv4 prefix length and the common IPv6 ones in reference tables.

Common questions

Why are two addresses lost in every IPv4 subnet?

The first address names the network and the last is the broadcast address, so a /24 has 256 addresses but 254 for devices. A /31 (a link between two routers) and a /32 (one host) are the exceptions.

What size of IPv6 network should a LAN use?

Always /64. Devices pick their own address within it (SLAAC), which needs the full 64 bits. A site usually gets a /48 or /56 from its provider, which holds 65,536 or 256 LANs.

What is a wildcard mask?

The subnet mask turned inside out: 255.255.255.0 becomes 0.0.0.255. Cisco access lists and OSPF use it to say which bits must match.

Which ranges can I use inside an office?

IPv4: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. IPv6: unique local addresses from fd00::/8, though most networks use the public prefix from their provider.