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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.

Network115.9.0.0/18
Usable hosts16,382
Subnet mask255.255.192.0
Addresses16,384
Network address
115.9.0.0
Broadcast address
115.9.63.255
First usable
115.9.0.1
Last usable
115.9.63.254
Usable hosts
16,382 (16,384 less the network and broadcast addresses)
Subnet mask
255.255.192.0
Wildcard mask
0.0.63.255 (Cisco ACLs, OSPF)
Prefix length
/18
Type
Public public
Old class
A (default /8)
As numbers
Hex 73090000 · Integer 1929969664 to 1929986047
Reverse DNS zones
0.9.115.in-addr.arpa
1.9.115.in-addr.arpa
2.9.115.in-addr.arpa
3.9.115.in-addr.arpa
4.9.115.in-addr.arpa
5.9.115.in-addr.arpa
6.9.115.in-addr.arpa
7.9.115.in-addr.arpa
8.9.115.in-addr.arpa
9.9.115.in-addr.arpa
10.9.115.in-addr.arpa
11.9.115.in-addr.arpa
12.9.115.in-addr.arpa
13.9.115.in-addr.arpa
14.9.115.in-addr.arpa
15.9.115.in-addr.arpa
and 48 more
/18 is not on a 8-bit boundary, so it takes 64 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01110011.00001001.00000000.00000000115.9.0.0
Subnet mask11111111.11111111.11000000.00000000255.255.192.0
Network01110011.00001001.00000000.00000000115.9.0.0
Broadcast01110011.00001001.00111111.11111111115.9.63.255
Split into smaller subnets/28
/19 (2)/20 (4)/21 (8)/22 (16)/23 (32)/24 (64)/25 (128)/26 (256)/27 (512)/28 (1,024)/29 (2,048)/30 (4,096)

115.9.0.0/18 makes 1,024 subnets of /28; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1115.9.0.0/28115.9.0.1 to 115.9.0.14115.9.0.1514
2115.9.0.16/28115.9.0.17 to 115.9.0.30115.9.0.3114
3115.9.0.32/28115.9.0.33 to 115.9.0.46115.9.0.4714
4115.9.0.48/28115.9.0.49 to 115.9.0.62115.9.0.6314
5115.9.0.64/28115.9.0.65 to 115.9.0.78115.9.0.7914
6115.9.0.80/28115.9.0.81 to 115.9.0.94115.9.0.9514
7115.9.0.96/28115.9.0.97 to 115.9.0.110115.9.0.11114
8115.9.0.112/28115.9.0.113 to 115.9.0.126115.9.0.12714
9115.9.0.128/28115.9.0.129 to 115.9.0.142115.9.0.14314
10115.9.0.144/28115.9.0.145 to 115.9.0.158115.9.0.15914
11115.9.0.160/28115.9.0.161 to 115.9.0.174115.9.0.17514
12115.9.0.176/28115.9.0.177 to 115.9.0.190115.9.0.19114
13115.9.0.192/28115.9.0.193 to 115.9.0.206115.9.0.20714
14115.9.0.208/28115.9.0.209 to 115.9.0.222115.9.0.22314
15115.9.0.224/28115.9.0.225 to 115.9.0.238115.9.0.23914
16115.9.0.240/28115.9.0.241 to 115.9.0.254115.9.0.25514
17115.9.1.0/28115.9.1.1 to 115.9.1.14115.9.1.1514
18115.9.1.16/28115.9.1.17 to 115.9.1.30115.9.1.3114
19115.9.1.32/28115.9.1.33 to 115.9.1.46115.9.1.4714
20115.9.1.48/28115.9.1.49 to 115.9.1.62115.9.1.6314
21115.9.1.64/28115.9.1.65 to 115.9.1.78115.9.1.7914
22115.9.1.80/28115.9.1.81 to 115.9.1.94115.9.1.9514
23115.9.1.96/28115.9.1.97 to 115.9.1.110115.9.1.11114
24115.9.1.112/28115.9.1.113 to 115.9.1.126115.9.1.12714
25115.9.1.128/28115.9.1.129 to 115.9.1.142115.9.1.14314
26115.9.1.144/28115.9.1.145 to 115.9.1.158115.9.1.15914
27115.9.1.160/28115.9.1.161 to 115.9.1.174115.9.1.17514
28115.9.1.176/28115.9.1.177 to 115.9.1.190115.9.1.19114
29115.9.1.192/28115.9.1.193 to 115.9.1.206115.9.1.20714
30115.9.1.208/28115.9.1.209 to 115.9.1.222115.9.1.22314
31115.9.1.224/28115.9.1.225 to 115.9.1.238115.9.1.23914
32115.9.1.240/28115.9.1.241 to 115.9.1.254115.9.1.25514
33115.9.2.0/28115.9.2.1 to 115.9.2.14115.9.2.1514
34115.9.2.16/28115.9.2.17 to 115.9.2.30115.9.2.3114
35115.9.2.32/28115.9.2.33 to 115.9.2.46115.9.2.4714
36115.9.2.48/28115.9.2.49 to 115.9.2.62115.9.2.6314
37115.9.2.64/28115.9.2.65 to 115.9.2.78115.9.2.7914
38115.9.2.80/28115.9.2.81 to 115.9.2.94115.9.2.9514
39115.9.2.96/28115.9.2.97 to 115.9.2.110115.9.2.11114
40115.9.2.112/28115.9.2.113 to 115.9.2.126115.9.2.12714
41115.9.2.128/28115.9.2.129 to 115.9.2.142115.9.2.14314
42115.9.2.144/28115.9.2.145 to 115.9.2.158115.9.2.15914
43115.9.2.160/28115.9.2.161 to 115.9.2.174115.9.2.17514
44115.9.2.176/28115.9.2.177 to 115.9.2.190115.9.2.19114
45115.9.2.192/28115.9.2.193 to 115.9.2.206115.9.2.20714
46115.9.2.208/28115.9.2.209 to 115.9.2.222115.9.2.22314
47115.9.2.224/28115.9.2.225 to 115.9.2.238115.9.2.23914
48115.9.2.240/28115.9.2.241 to 115.9.2.254115.9.2.25514
49115.9.3.0/28115.9.3.1 to 115.9.3.14115.9.3.1514
50115.9.3.16/28115.9.3.17 to 115.9.3.30115.9.3.3114
51115.9.3.32/28115.9.3.33 to 115.9.3.46115.9.3.4714
52115.9.3.48/28115.9.3.49 to 115.9.3.62115.9.3.6314
53115.9.3.64/28115.9.3.65 to 115.9.3.78115.9.3.7914
54115.9.3.80/28115.9.3.81 to 115.9.3.94115.9.3.9514
55115.9.3.96/28115.9.3.97 to 115.9.3.110115.9.3.11114
56115.9.3.112/28115.9.3.113 to 115.9.3.126115.9.3.12714
57115.9.3.128/28115.9.3.129 to 115.9.3.142115.9.3.14314
58115.9.3.144/28115.9.3.145 to 115.9.3.158115.9.3.15914
59115.9.3.160/28115.9.3.161 to 115.9.3.174115.9.3.17514
60115.9.3.176/28115.9.3.177 to 115.9.3.190115.9.3.19114
61115.9.3.192/28115.9.3.193 to 115.9.3.206115.9.3.20714
62115.9.3.208/28115.9.3.209 to 115.9.3.222115.9.3.22314
63115.9.3.224/28115.9.3.225 to 115.9.3.238115.9.3.23914
64115.9.3.240/28115.9.3.241 to 115.9.3.254115.9.3.25514
65115.9.4.0/28115.9.4.1 to 115.9.4.14115.9.4.1514
66115.9.4.16/28115.9.4.17 to 115.9.4.30115.9.4.3114
67115.9.4.32/28115.9.4.33 to 115.9.4.46115.9.4.4714
68115.9.4.48/28115.9.4.49 to 115.9.4.62115.9.4.6314
69115.9.4.64/28115.9.4.65 to 115.9.4.78115.9.4.7914
70115.9.4.80/28115.9.4.81 to 115.9.4.94115.9.4.9514
71115.9.4.96/28115.9.4.97 to 115.9.4.110115.9.4.11114
72115.9.4.112/28115.9.4.113 to 115.9.4.126115.9.4.12714
73115.9.4.128/28115.9.4.129 to 115.9.4.142115.9.4.14314
74115.9.4.144/28115.9.4.145 to 115.9.4.158115.9.4.15914
75115.9.4.160/28115.9.4.161 to 115.9.4.174115.9.4.17514
76115.9.4.176/28115.9.4.177 to 115.9.4.190115.9.4.19114
77115.9.4.192/28115.9.4.193 to 115.9.4.206115.9.4.20714
78115.9.4.208/28115.9.4.209 to 115.9.4.222115.9.4.22314
79115.9.4.224/28115.9.4.225 to 115.9.4.238115.9.4.23914
80115.9.4.240/28115.9.4.241 to 115.9.4.254115.9.4.25514
81115.9.5.0/28115.9.5.1 to 115.9.5.14115.9.5.1514
82115.9.5.16/28115.9.5.17 to 115.9.5.30115.9.5.3114
83115.9.5.32/28115.9.5.33 to 115.9.5.46115.9.5.4714
84115.9.5.48/28115.9.5.49 to 115.9.5.62115.9.5.6314
85115.9.5.64/28115.9.5.65 to 115.9.5.78115.9.5.7914
86115.9.5.80/28115.9.5.81 to 115.9.5.94115.9.5.9514
87115.9.5.96/28115.9.5.97 to 115.9.5.110115.9.5.11114
88115.9.5.112/28115.9.5.113 to 115.9.5.126115.9.5.12714
89115.9.5.128/28115.9.5.129 to 115.9.5.142115.9.5.14314
90115.9.5.144/28115.9.5.145 to 115.9.5.158115.9.5.15914
91115.9.5.160/28115.9.5.161 to 115.9.5.174115.9.5.17514
92115.9.5.176/28115.9.5.177 to 115.9.5.190115.9.5.19114
93115.9.5.192/28115.9.5.193 to 115.9.5.206115.9.5.20714
94115.9.5.208/28115.9.5.209 to 115.9.5.222115.9.5.22314
95115.9.5.224/28115.9.5.225 to 115.9.5.238115.9.5.23914
96115.9.5.240/28115.9.5.241 to 115.9.5.254115.9.5.25514
97115.9.6.0/28115.9.6.1 to 115.9.6.14115.9.6.1514
98115.9.6.16/28115.9.6.17 to 115.9.6.30115.9.6.3114
99115.9.6.32/28115.9.6.33 to 115.9.6.46115.9.6.4714
100115.9.6.48/28115.9.6.49 to 115.9.6.62115.9.6.6314
101115.9.6.64/28115.9.6.65 to 115.9.6.78115.9.6.7914
102115.9.6.80/28115.9.6.81 to 115.9.6.94115.9.6.9514
103115.9.6.96/28115.9.6.97 to 115.9.6.110115.9.6.11114
104115.9.6.112/28115.9.6.113 to 115.9.6.126115.9.6.12714
105115.9.6.128/28115.9.6.129 to 115.9.6.142115.9.6.14314
106115.9.6.144/28115.9.6.145 to 115.9.6.158115.9.6.15914
107115.9.6.160/28115.9.6.161 to 115.9.6.174115.9.6.17514
108115.9.6.176/28115.9.6.177 to 115.9.6.190115.9.6.19114
109115.9.6.192/28115.9.6.193 to 115.9.6.206115.9.6.20714
110115.9.6.208/28115.9.6.209 to 115.9.6.222115.9.6.22314
111115.9.6.224/28115.9.6.225 to 115.9.6.238115.9.6.23914
112115.9.6.240/28115.9.6.241 to 115.9.6.254115.9.6.25514
113115.9.7.0/28115.9.7.1 to 115.9.7.14115.9.7.1514
114115.9.7.16/28115.9.7.17 to 115.9.7.30115.9.7.3114
115115.9.7.32/28115.9.7.33 to 115.9.7.46115.9.7.4714
116115.9.7.48/28115.9.7.49 to 115.9.7.62115.9.7.6314
117115.9.7.64/28115.9.7.65 to 115.9.7.78115.9.7.7914
118115.9.7.80/28115.9.7.81 to 115.9.7.94115.9.7.9514
119115.9.7.96/28115.9.7.97 to 115.9.7.110115.9.7.11114
120115.9.7.112/28115.9.7.113 to 115.9.7.126115.9.7.12714
121115.9.7.128/28115.9.7.129 to 115.9.7.142115.9.7.14314
122115.9.7.144/28115.9.7.145 to 115.9.7.158115.9.7.15914
123115.9.7.160/28115.9.7.161 to 115.9.7.174115.9.7.17514
124115.9.7.176/28115.9.7.177 to 115.9.7.190115.9.7.19114
125115.9.7.192/28115.9.7.193 to 115.9.7.206115.9.7.20714
126115.9.7.208/28115.9.7.209 to 115.9.7.222115.9.7.22314
127115.9.7.224/28115.9.7.225 to 115.9.7.238115.9.7.23914
128115.9.7.240/28115.9.7.241 to 115.9.7.254115.9.7.25514
129115.9.8.0/28115.9.8.1 to 115.9.8.14115.9.8.1514
130115.9.8.16/28115.9.8.17 to 115.9.8.30115.9.8.3114
131115.9.8.32/28115.9.8.33 to 115.9.8.46115.9.8.4714
132115.9.8.48/28115.9.8.49 to 115.9.8.62115.9.8.6314
133115.9.8.64/28115.9.8.65 to 115.9.8.78115.9.8.7914
134115.9.8.80/28115.9.8.81 to 115.9.8.94115.9.8.9514
135115.9.8.96/28115.9.8.97 to 115.9.8.110115.9.8.11114
136115.9.8.112/28115.9.8.113 to 115.9.8.126115.9.8.12714
137115.9.8.128/28115.9.8.129 to 115.9.8.142115.9.8.14314
138115.9.8.144/28115.9.8.145 to 115.9.8.158115.9.8.15914
139115.9.8.160/28115.9.8.161 to 115.9.8.174115.9.8.17514
140115.9.8.176/28115.9.8.177 to 115.9.8.190115.9.8.19114
141115.9.8.192/28115.9.8.193 to 115.9.8.206115.9.8.20714
142115.9.8.208/28115.9.8.209 to 115.9.8.222115.9.8.22314
143115.9.8.224/28115.9.8.225 to 115.9.8.238115.9.8.23914
144115.9.8.240/28115.9.8.241 to 115.9.8.254115.9.8.25514
145115.9.9.0/28115.9.9.1 to 115.9.9.14115.9.9.1514
146115.9.9.16/28115.9.9.17 to 115.9.9.30115.9.9.3114
147115.9.9.32/28115.9.9.33 to 115.9.9.46115.9.9.4714
148115.9.9.48/28115.9.9.49 to 115.9.9.62115.9.9.6314
149115.9.9.64/28115.9.9.65 to 115.9.9.78115.9.9.7914
150115.9.9.80/28115.9.9.81 to 115.9.9.94115.9.9.9514
151115.9.9.96/28115.9.9.97 to 115.9.9.110115.9.9.11114
152115.9.9.112/28115.9.9.113 to 115.9.9.126115.9.9.12714
153115.9.9.128/28115.9.9.129 to 115.9.9.142115.9.9.14314
154115.9.9.144/28115.9.9.145 to 115.9.9.158115.9.9.15914
155115.9.9.160/28115.9.9.161 to 115.9.9.174115.9.9.17514
156115.9.9.176/28115.9.9.177 to 115.9.9.190115.9.9.19114
157115.9.9.192/28115.9.9.193 to 115.9.9.206115.9.9.20714
158115.9.9.208/28115.9.9.209 to 115.9.9.222115.9.9.22314
159115.9.9.224/28115.9.9.225 to 115.9.9.238115.9.9.23914
160115.9.9.240/28115.9.9.241 to 115.9.9.254115.9.9.25514
161115.9.10.0/28115.9.10.1 to 115.9.10.14115.9.10.1514
162115.9.10.16/28115.9.10.17 to 115.9.10.30115.9.10.3114
163115.9.10.32/28115.9.10.33 to 115.9.10.46115.9.10.4714
164115.9.10.48/28115.9.10.49 to 115.9.10.62115.9.10.6314
165115.9.10.64/28115.9.10.65 to 115.9.10.78115.9.10.7914
166115.9.10.80/28115.9.10.81 to 115.9.10.94115.9.10.9514
167115.9.10.96/28115.9.10.97 to 115.9.10.110115.9.10.11114
168115.9.10.112/28115.9.10.113 to 115.9.10.126115.9.10.12714
169115.9.10.128/28115.9.10.129 to 115.9.10.142115.9.10.14314
170115.9.10.144/28115.9.10.145 to 115.9.10.158115.9.10.15914
171115.9.10.160/28115.9.10.161 to 115.9.10.174115.9.10.17514
172115.9.10.176/28115.9.10.177 to 115.9.10.190115.9.10.19114
173115.9.10.192/28115.9.10.193 to 115.9.10.206115.9.10.20714
174115.9.10.208/28115.9.10.209 to 115.9.10.222115.9.10.22314
175115.9.10.224/28115.9.10.225 to 115.9.10.238115.9.10.23914
176115.9.10.240/28115.9.10.241 to 115.9.10.254115.9.10.25514
177115.9.11.0/28115.9.11.1 to 115.9.11.14115.9.11.1514
178115.9.11.16/28115.9.11.17 to 115.9.11.30115.9.11.3114
179115.9.11.32/28115.9.11.33 to 115.9.11.46115.9.11.4714
180115.9.11.48/28115.9.11.49 to 115.9.11.62115.9.11.6314
181115.9.11.64/28115.9.11.65 to 115.9.11.78115.9.11.7914
182115.9.11.80/28115.9.11.81 to 115.9.11.94115.9.11.9514
183115.9.11.96/28115.9.11.97 to 115.9.11.110115.9.11.11114
184115.9.11.112/28115.9.11.113 to 115.9.11.126115.9.11.12714
185115.9.11.128/28115.9.11.129 to 115.9.11.142115.9.11.14314
186115.9.11.144/28115.9.11.145 to 115.9.11.158115.9.11.15914
187115.9.11.160/28115.9.11.161 to 115.9.11.174115.9.11.17514
188115.9.11.176/28115.9.11.177 to 115.9.11.190115.9.11.19114
189115.9.11.192/28115.9.11.193 to 115.9.11.206115.9.11.20714
190115.9.11.208/28115.9.11.209 to 115.9.11.222115.9.11.22314
191115.9.11.224/28115.9.11.225 to 115.9.11.238115.9.11.23914
192115.9.11.240/28115.9.11.241 to 115.9.11.254115.9.11.25514
193115.9.12.0/28115.9.12.1 to 115.9.12.14115.9.12.1514
194115.9.12.16/28115.9.12.17 to 115.9.12.30115.9.12.3114
195115.9.12.32/28115.9.12.33 to 115.9.12.46115.9.12.4714
196115.9.12.48/28115.9.12.49 to 115.9.12.62115.9.12.6314
197115.9.12.64/28115.9.12.65 to 115.9.12.78115.9.12.7914
198115.9.12.80/28115.9.12.81 to 115.9.12.94115.9.12.9514
199115.9.12.96/28115.9.12.97 to 115.9.12.110115.9.12.11114
200115.9.12.112/28115.9.12.113 to 115.9.12.126115.9.12.12714
201115.9.12.128/28115.9.12.129 to 115.9.12.142115.9.12.14314
202115.9.12.144/28115.9.12.145 to 115.9.12.158115.9.12.15914
203115.9.12.160/28115.9.12.161 to 115.9.12.174115.9.12.17514
204115.9.12.176/28115.9.12.177 to 115.9.12.190115.9.12.19114
205115.9.12.192/28115.9.12.193 to 115.9.12.206115.9.12.20714
206115.9.12.208/28115.9.12.209 to 115.9.12.222115.9.12.22314
207115.9.12.224/28115.9.12.225 to 115.9.12.238115.9.12.23914
208115.9.12.240/28115.9.12.241 to 115.9.12.254115.9.12.25514
209115.9.13.0/28115.9.13.1 to 115.9.13.14115.9.13.1514
210115.9.13.16/28115.9.13.17 to 115.9.13.30115.9.13.3114
211115.9.13.32/28115.9.13.33 to 115.9.13.46115.9.13.4714
212115.9.13.48/28115.9.13.49 to 115.9.13.62115.9.13.6314
213115.9.13.64/28115.9.13.65 to 115.9.13.78115.9.13.7914
214115.9.13.80/28115.9.13.81 to 115.9.13.94115.9.13.9514
215115.9.13.96/28115.9.13.97 to 115.9.13.110115.9.13.11114
216115.9.13.112/28115.9.13.113 to 115.9.13.126115.9.13.12714
217115.9.13.128/28115.9.13.129 to 115.9.13.142115.9.13.14314
218115.9.13.144/28115.9.13.145 to 115.9.13.158115.9.13.15914
219115.9.13.160/28115.9.13.161 to 115.9.13.174115.9.13.17514
220115.9.13.176/28115.9.13.177 to 115.9.13.190115.9.13.19114
221115.9.13.192/28115.9.13.193 to 115.9.13.206115.9.13.20714
222115.9.13.208/28115.9.13.209 to 115.9.13.222115.9.13.22314
223115.9.13.224/28115.9.13.225 to 115.9.13.238115.9.13.23914
224115.9.13.240/28115.9.13.241 to 115.9.13.254115.9.13.25514
225115.9.14.0/28115.9.14.1 to 115.9.14.14115.9.14.1514
226115.9.14.16/28115.9.14.17 to 115.9.14.30115.9.14.3114
227115.9.14.32/28115.9.14.33 to 115.9.14.46115.9.14.4714
228115.9.14.48/28115.9.14.49 to 115.9.14.62115.9.14.6314
229115.9.14.64/28115.9.14.65 to 115.9.14.78115.9.14.7914
230115.9.14.80/28115.9.14.81 to 115.9.14.94115.9.14.9514
231115.9.14.96/28115.9.14.97 to 115.9.14.110115.9.14.11114
232115.9.14.112/28115.9.14.113 to 115.9.14.126115.9.14.12714
233115.9.14.128/28115.9.14.129 to 115.9.14.142115.9.14.14314
234115.9.14.144/28115.9.14.145 to 115.9.14.158115.9.14.15914
235115.9.14.160/28115.9.14.161 to 115.9.14.174115.9.14.17514
236115.9.14.176/28115.9.14.177 to 115.9.14.190115.9.14.19114
237115.9.14.192/28115.9.14.193 to 115.9.14.206115.9.14.20714
238115.9.14.208/28115.9.14.209 to 115.9.14.222115.9.14.22314
239115.9.14.224/28115.9.14.225 to 115.9.14.238115.9.14.23914
240115.9.14.240/28115.9.14.241 to 115.9.14.254115.9.14.25514
241115.9.15.0/28115.9.15.1 to 115.9.15.14115.9.15.1514
242115.9.15.16/28115.9.15.17 to 115.9.15.30115.9.15.3114
243115.9.15.32/28115.9.15.33 to 115.9.15.46115.9.15.4714
244115.9.15.48/28115.9.15.49 to 115.9.15.62115.9.15.6314
245115.9.15.64/28115.9.15.65 to 115.9.15.78115.9.15.7914
246115.9.15.80/28115.9.15.81 to 115.9.15.94115.9.15.9514
247115.9.15.96/28115.9.15.97 to 115.9.15.110115.9.15.11114
248115.9.15.112/28115.9.15.113 to 115.9.15.126115.9.15.12714
249115.9.15.128/28115.9.15.129 to 115.9.15.142115.9.15.14314
250115.9.15.144/28115.9.15.145 to 115.9.15.158115.9.15.15914
251115.9.15.160/28115.9.15.161 to 115.9.15.174115.9.15.17514
252115.9.15.176/28115.9.15.177 to 115.9.15.190115.9.15.19114
253115.9.15.192/28115.9.15.193 to 115.9.15.206115.9.15.20714
254115.9.15.208/28115.9.15.209 to 115.9.15.222115.9.15.22314
255115.9.15.224/28115.9.15.225 to 115.9.15.238115.9.15.23914
256115.9.15.240/28115.9.15.241 to 115.9.15.254115.9.15.25514

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.