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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.

Network115.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
115.0.0.0
Broadcast address
115.255.255.255
First usable
115.0.0.1
Last usable
115.255.255.254
Usable hosts
16,777,214 (16,777,216 less the network and broadcast addresses)
Subnet mask
255.0.0.0
Wildcard mask
0.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/8
Type
Public public
Old class
A (default /8)
As numbers
Hex 73000000 · Integer 1929379840 to 1946157055
Reverse DNS zone
115.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01110011..00000000.00000000.00000000115.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network01110011..00000000.00000000.00000000115.0.0.0
Broadcast01110011..11111111.11111111.11111111115.255.255.255
Split into smaller subnets/18
/9 (2)/10 (4)/11 (8)/12 (16)/13 (32)/14 (64)/15 (128)/16 (256)/17 (512)/18 (1,024)/19 (2,048)/20 (4,096)

115.0.0.0/8 makes 1,024 subnets of /18; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1115.0.0.0/18115.0.0.1 to 115.0.63.254115.0.63.25516,382
2115.0.64.0/18115.0.64.1 to 115.0.127.254115.0.127.25516,382
3115.0.128.0/18115.0.128.1 to 115.0.191.254115.0.191.25516,382
4115.0.192.0/18115.0.192.1 to 115.0.255.254115.0.255.25516,382
5115.1.0.0/18115.1.0.1 to 115.1.63.254115.1.63.25516,382
6115.1.64.0/18115.1.64.1 to 115.1.127.254115.1.127.25516,382
7115.1.128.0/18115.1.128.1 to 115.1.191.254115.1.191.25516,382
8115.1.192.0/18115.1.192.1 to 115.1.255.254115.1.255.25516,382
9115.2.0.0/18115.2.0.1 to 115.2.63.254115.2.63.25516,382
10115.2.64.0/18115.2.64.1 to 115.2.127.254115.2.127.25516,382
11115.2.128.0/18115.2.128.1 to 115.2.191.254115.2.191.25516,382
12115.2.192.0/18115.2.192.1 to 115.2.255.254115.2.255.25516,382
13115.3.0.0/18115.3.0.1 to 115.3.63.254115.3.63.25516,382
14115.3.64.0/18115.3.64.1 to 115.3.127.254115.3.127.25516,382
15115.3.128.0/18115.3.128.1 to 115.3.191.254115.3.191.25516,382
16115.3.192.0/18115.3.192.1 to 115.3.255.254115.3.255.25516,382
17115.4.0.0/18115.4.0.1 to 115.4.63.254115.4.63.25516,382
18115.4.64.0/18115.4.64.1 to 115.4.127.254115.4.127.25516,382
19115.4.128.0/18115.4.128.1 to 115.4.191.254115.4.191.25516,382
20115.4.192.0/18115.4.192.1 to 115.4.255.254115.4.255.25516,382
21115.5.0.0/18115.5.0.1 to 115.5.63.254115.5.63.25516,382
22115.5.64.0/18115.5.64.1 to 115.5.127.254115.5.127.25516,382
23115.5.128.0/18115.5.128.1 to 115.5.191.254115.5.191.25516,382
24115.5.192.0/18115.5.192.1 to 115.5.255.254115.5.255.25516,382
25115.6.0.0/18115.6.0.1 to 115.6.63.254115.6.63.25516,382
26115.6.64.0/18115.6.64.1 to 115.6.127.254115.6.127.25516,382
27115.6.128.0/18115.6.128.1 to 115.6.191.254115.6.191.25516,382
28115.6.192.0/18115.6.192.1 to 115.6.255.254115.6.255.25516,382
29115.7.0.0/18115.7.0.1 to 115.7.63.254115.7.63.25516,382
30115.7.64.0/18115.7.64.1 to 115.7.127.254115.7.127.25516,382
31115.7.128.0/18115.7.128.1 to 115.7.191.254115.7.191.25516,382
32115.7.192.0/18115.7.192.1 to 115.7.255.254115.7.255.25516,382
33115.8.0.0/18115.8.0.1 to 115.8.63.254115.8.63.25516,382
34115.8.64.0/18115.8.64.1 to 115.8.127.254115.8.127.25516,382
35115.8.128.0/18115.8.128.1 to 115.8.191.254115.8.191.25516,382
36115.8.192.0/18115.8.192.1 to 115.8.255.254115.8.255.25516,382
37115.9.0.0/18115.9.0.1 to 115.9.63.254115.9.63.25516,382
38115.9.64.0/18115.9.64.1 to 115.9.127.254115.9.127.25516,382
39115.9.128.0/18115.9.128.1 to 115.9.191.254115.9.191.25516,382
40115.9.192.0/18115.9.192.1 to 115.9.255.254115.9.255.25516,382
41115.10.0.0/18115.10.0.1 to 115.10.63.254115.10.63.25516,382
42115.10.64.0/18115.10.64.1 to 115.10.127.254115.10.127.25516,382
43115.10.128.0/18115.10.128.1 to 115.10.191.254115.10.191.25516,382
44115.10.192.0/18115.10.192.1 to 115.10.255.254115.10.255.25516,382
45115.11.0.0/18115.11.0.1 to 115.11.63.254115.11.63.25516,382
46115.11.64.0/18115.11.64.1 to 115.11.127.254115.11.127.25516,382
47115.11.128.0/18115.11.128.1 to 115.11.191.254115.11.191.25516,382
48115.11.192.0/18115.11.192.1 to 115.11.255.254115.11.255.25516,382
49115.12.0.0/18115.12.0.1 to 115.12.63.254115.12.63.25516,382
50115.12.64.0/18115.12.64.1 to 115.12.127.254115.12.127.25516,382
51115.12.128.0/18115.12.128.1 to 115.12.191.254115.12.191.25516,382
52115.12.192.0/18115.12.192.1 to 115.12.255.254115.12.255.25516,382
53115.13.0.0/18115.13.0.1 to 115.13.63.254115.13.63.25516,382
54115.13.64.0/18115.13.64.1 to 115.13.127.254115.13.127.25516,382
55115.13.128.0/18115.13.128.1 to 115.13.191.254115.13.191.25516,382
56115.13.192.0/18115.13.192.1 to 115.13.255.254115.13.255.25516,382
57115.14.0.0/18115.14.0.1 to 115.14.63.254115.14.63.25516,382
58115.14.64.0/18115.14.64.1 to 115.14.127.254115.14.127.25516,382
59115.14.128.0/18115.14.128.1 to 115.14.191.254115.14.191.25516,382
60115.14.192.0/18115.14.192.1 to 115.14.255.254115.14.255.25516,382
61115.15.0.0/18115.15.0.1 to 115.15.63.254115.15.63.25516,382
62115.15.64.0/18115.15.64.1 to 115.15.127.254115.15.127.25516,382
63115.15.128.0/18115.15.128.1 to 115.15.191.254115.15.191.25516,382
64115.15.192.0/18115.15.192.1 to 115.15.255.254115.15.255.25516,382
65115.16.0.0/18115.16.0.1 to 115.16.63.254115.16.63.25516,382
66115.16.64.0/18115.16.64.1 to 115.16.127.254115.16.127.25516,382
67115.16.128.0/18115.16.128.1 to 115.16.191.254115.16.191.25516,382
68115.16.192.0/18115.16.192.1 to 115.16.255.254115.16.255.25516,382
69115.17.0.0/18115.17.0.1 to 115.17.63.254115.17.63.25516,382
70115.17.64.0/18115.17.64.1 to 115.17.127.254115.17.127.25516,382
71115.17.128.0/18115.17.128.1 to 115.17.191.254115.17.191.25516,382
72115.17.192.0/18115.17.192.1 to 115.17.255.254115.17.255.25516,382
73115.18.0.0/18115.18.0.1 to 115.18.63.254115.18.63.25516,382
74115.18.64.0/18115.18.64.1 to 115.18.127.254115.18.127.25516,382
75115.18.128.0/18115.18.128.1 to 115.18.191.254115.18.191.25516,382
76115.18.192.0/18115.18.192.1 to 115.18.255.254115.18.255.25516,382
77115.19.0.0/18115.19.0.1 to 115.19.63.254115.19.63.25516,382
78115.19.64.0/18115.19.64.1 to 115.19.127.254115.19.127.25516,382
79115.19.128.0/18115.19.128.1 to 115.19.191.254115.19.191.25516,382
80115.19.192.0/18115.19.192.1 to 115.19.255.254115.19.255.25516,382
81115.20.0.0/18115.20.0.1 to 115.20.63.254115.20.63.25516,382
82115.20.64.0/18115.20.64.1 to 115.20.127.254115.20.127.25516,382
83115.20.128.0/18115.20.128.1 to 115.20.191.254115.20.191.25516,382
84115.20.192.0/18115.20.192.1 to 115.20.255.254115.20.255.25516,382
85115.21.0.0/18115.21.0.1 to 115.21.63.254115.21.63.25516,382
86115.21.64.0/18115.21.64.1 to 115.21.127.254115.21.127.25516,382
87115.21.128.0/18115.21.128.1 to 115.21.191.254115.21.191.25516,382
88115.21.192.0/18115.21.192.1 to 115.21.255.254115.21.255.25516,382
89115.22.0.0/18115.22.0.1 to 115.22.63.254115.22.63.25516,382
90115.22.64.0/18115.22.64.1 to 115.22.127.254115.22.127.25516,382
91115.22.128.0/18115.22.128.1 to 115.22.191.254115.22.191.25516,382
92115.22.192.0/18115.22.192.1 to 115.22.255.254115.22.255.25516,382
93115.23.0.0/18115.23.0.1 to 115.23.63.254115.23.63.25516,382
94115.23.64.0/18115.23.64.1 to 115.23.127.254115.23.127.25516,382
95115.23.128.0/18115.23.128.1 to 115.23.191.254115.23.191.25516,382
96115.23.192.0/18115.23.192.1 to 115.23.255.254115.23.255.25516,382
97115.24.0.0/18115.24.0.1 to 115.24.63.254115.24.63.25516,382
98115.24.64.0/18115.24.64.1 to 115.24.127.254115.24.127.25516,382
99115.24.128.0/18115.24.128.1 to 115.24.191.254115.24.191.25516,382
100115.24.192.0/18115.24.192.1 to 115.24.255.254115.24.255.25516,382
101115.25.0.0/18115.25.0.1 to 115.25.63.254115.25.63.25516,382
102115.25.64.0/18115.25.64.1 to 115.25.127.254115.25.127.25516,382
103115.25.128.0/18115.25.128.1 to 115.25.191.254115.25.191.25516,382
104115.25.192.0/18115.25.192.1 to 115.25.255.254115.25.255.25516,382
105115.26.0.0/18115.26.0.1 to 115.26.63.254115.26.63.25516,382
106115.26.64.0/18115.26.64.1 to 115.26.127.254115.26.127.25516,382
107115.26.128.0/18115.26.128.1 to 115.26.191.254115.26.191.25516,382
108115.26.192.0/18115.26.192.1 to 115.26.255.254115.26.255.25516,382
109115.27.0.0/18115.27.0.1 to 115.27.63.254115.27.63.25516,382
110115.27.64.0/18115.27.64.1 to 115.27.127.254115.27.127.25516,382
111115.27.128.0/18115.27.128.1 to 115.27.191.254115.27.191.25516,382
112115.27.192.0/18115.27.192.1 to 115.27.255.254115.27.255.25516,382
113115.28.0.0/18115.28.0.1 to 115.28.63.254115.28.63.25516,382
114115.28.64.0/18115.28.64.1 to 115.28.127.254115.28.127.25516,382
115115.28.128.0/18115.28.128.1 to 115.28.191.254115.28.191.25516,382
116115.28.192.0/18115.28.192.1 to 115.28.255.254115.28.255.25516,382
117115.29.0.0/18115.29.0.1 to 115.29.63.254115.29.63.25516,382
118115.29.64.0/18115.29.64.1 to 115.29.127.254115.29.127.25516,382
119115.29.128.0/18115.29.128.1 to 115.29.191.254115.29.191.25516,382
120115.29.192.0/18115.29.192.1 to 115.29.255.254115.29.255.25516,382
121115.30.0.0/18115.30.0.1 to 115.30.63.254115.30.63.25516,382
122115.30.64.0/18115.30.64.1 to 115.30.127.254115.30.127.25516,382
123115.30.128.0/18115.30.128.1 to 115.30.191.254115.30.191.25516,382
124115.30.192.0/18115.30.192.1 to 115.30.255.254115.30.255.25516,382
125115.31.0.0/18115.31.0.1 to 115.31.63.254115.31.63.25516,382
126115.31.64.0/18115.31.64.1 to 115.31.127.254115.31.127.25516,382
127115.31.128.0/18115.31.128.1 to 115.31.191.254115.31.191.25516,382
128115.31.192.0/18115.31.192.1 to 115.31.255.254115.31.255.25516,382
129115.32.0.0/18115.32.0.1 to 115.32.63.254115.32.63.25516,382
130115.32.64.0/18115.32.64.1 to 115.32.127.254115.32.127.25516,382
131115.32.128.0/18115.32.128.1 to 115.32.191.254115.32.191.25516,382
132115.32.192.0/18115.32.192.1 to 115.32.255.254115.32.255.25516,382
133115.33.0.0/18115.33.0.1 to 115.33.63.254115.33.63.25516,382
134115.33.64.0/18115.33.64.1 to 115.33.127.254115.33.127.25516,382
135115.33.128.0/18115.33.128.1 to 115.33.191.254115.33.191.25516,382
136115.33.192.0/18115.33.192.1 to 115.33.255.254115.33.255.25516,382
137115.34.0.0/18115.34.0.1 to 115.34.63.254115.34.63.25516,382
138115.34.64.0/18115.34.64.1 to 115.34.127.254115.34.127.25516,382
139115.34.128.0/18115.34.128.1 to 115.34.191.254115.34.191.25516,382
140115.34.192.0/18115.34.192.1 to 115.34.255.254115.34.255.25516,382
141115.35.0.0/18115.35.0.1 to 115.35.63.254115.35.63.25516,382
142115.35.64.0/18115.35.64.1 to 115.35.127.254115.35.127.25516,382
143115.35.128.0/18115.35.128.1 to 115.35.191.254115.35.191.25516,382
144115.35.192.0/18115.35.192.1 to 115.35.255.254115.35.255.25516,382
145115.36.0.0/18115.36.0.1 to 115.36.63.254115.36.63.25516,382
146115.36.64.0/18115.36.64.1 to 115.36.127.254115.36.127.25516,382
147115.36.128.0/18115.36.128.1 to 115.36.191.254115.36.191.25516,382
148115.36.192.0/18115.36.192.1 to 115.36.255.254115.36.255.25516,382
149115.37.0.0/18115.37.0.1 to 115.37.63.254115.37.63.25516,382
150115.37.64.0/18115.37.64.1 to 115.37.127.254115.37.127.25516,382
151115.37.128.0/18115.37.128.1 to 115.37.191.254115.37.191.25516,382
152115.37.192.0/18115.37.192.1 to 115.37.255.254115.37.255.25516,382
153115.38.0.0/18115.38.0.1 to 115.38.63.254115.38.63.25516,382
154115.38.64.0/18115.38.64.1 to 115.38.127.254115.38.127.25516,382
155115.38.128.0/18115.38.128.1 to 115.38.191.254115.38.191.25516,382
156115.38.192.0/18115.38.192.1 to 115.38.255.254115.38.255.25516,382
157115.39.0.0/18115.39.0.1 to 115.39.63.254115.39.63.25516,382
158115.39.64.0/18115.39.64.1 to 115.39.127.254115.39.127.25516,382
159115.39.128.0/18115.39.128.1 to 115.39.191.254115.39.191.25516,382
160115.39.192.0/18115.39.192.1 to 115.39.255.254115.39.255.25516,382
161115.40.0.0/18115.40.0.1 to 115.40.63.254115.40.63.25516,382
162115.40.64.0/18115.40.64.1 to 115.40.127.254115.40.127.25516,382
163115.40.128.0/18115.40.128.1 to 115.40.191.254115.40.191.25516,382
164115.40.192.0/18115.40.192.1 to 115.40.255.254115.40.255.25516,382
165115.41.0.0/18115.41.0.1 to 115.41.63.254115.41.63.25516,382
166115.41.64.0/18115.41.64.1 to 115.41.127.254115.41.127.25516,382
167115.41.128.0/18115.41.128.1 to 115.41.191.254115.41.191.25516,382
168115.41.192.0/18115.41.192.1 to 115.41.255.254115.41.255.25516,382
169115.42.0.0/18115.42.0.1 to 115.42.63.254115.42.63.25516,382
170115.42.64.0/18115.42.64.1 to 115.42.127.254115.42.127.25516,382
171115.42.128.0/18115.42.128.1 to 115.42.191.254115.42.191.25516,382
172115.42.192.0/18115.42.192.1 to 115.42.255.254115.42.255.25516,382
173115.43.0.0/18115.43.0.1 to 115.43.63.254115.43.63.25516,382
174115.43.64.0/18115.43.64.1 to 115.43.127.254115.43.127.25516,382
175115.43.128.0/18115.43.128.1 to 115.43.191.254115.43.191.25516,382
176115.43.192.0/18115.43.192.1 to 115.43.255.254115.43.255.25516,382
177115.44.0.0/18115.44.0.1 to 115.44.63.254115.44.63.25516,382
178115.44.64.0/18115.44.64.1 to 115.44.127.254115.44.127.25516,382
179115.44.128.0/18115.44.128.1 to 115.44.191.254115.44.191.25516,382
180115.44.192.0/18115.44.192.1 to 115.44.255.254115.44.255.25516,382
181115.45.0.0/18115.45.0.1 to 115.45.63.254115.45.63.25516,382
182115.45.64.0/18115.45.64.1 to 115.45.127.254115.45.127.25516,382
183115.45.128.0/18115.45.128.1 to 115.45.191.254115.45.191.25516,382
184115.45.192.0/18115.45.192.1 to 115.45.255.254115.45.255.25516,382
185115.46.0.0/18115.46.0.1 to 115.46.63.254115.46.63.25516,382
186115.46.64.0/18115.46.64.1 to 115.46.127.254115.46.127.25516,382
187115.46.128.0/18115.46.128.1 to 115.46.191.254115.46.191.25516,382
188115.46.192.0/18115.46.192.1 to 115.46.255.254115.46.255.25516,382
189115.47.0.0/18115.47.0.1 to 115.47.63.254115.47.63.25516,382
190115.47.64.0/18115.47.64.1 to 115.47.127.254115.47.127.25516,382
191115.47.128.0/18115.47.128.1 to 115.47.191.254115.47.191.25516,382
192115.47.192.0/18115.47.192.1 to 115.47.255.254115.47.255.25516,382
193115.48.0.0/18115.48.0.1 to 115.48.63.254115.48.63.25516,382
194115.48.64.0/18115.48.64.1 to 115.48.127.254115.48.127.25516,382
195115.48.128.0/18115.48.128.1 to 115.48.191.254115.48.191.25516,382
196115.48.192.0/18115.48.192.1 to 115.48.255.254115.48.255.25516,382
197115.49.0.0/18115.49.0.1 to 115.49.63.254115.49.63.25516,382
198115.49.64.0/18115.49.64.1 to 115.49.127.254115.49.127.25516,382
199115.49.128.0/18115.49.128.1 to 115.49.191.254115.49.191.25516,382
200115.49.192.0/18115.49.192.1 to 115.49.255.254115.49.255.25516,382
201115.50.0.0/18115.50.0.1 to 115.50.63.254115.50.63.25516,382
202115.50.64.0/18115.50.64.1 to 115.50.127.254115.50.127.25516,382
203115.50.128.0/18115.50.128.1 to 115.50.191.254115.50.191.25516,382
204115.50.192.0/18115.50.192.1 to 115.50.255.254115.50.255.25516,382
205115.51.0.0/18115.51.0.1 to 115.51.63.254115.51.63.25516,382
206115.51.64.0/18115.51.64.1 to 115.51.127.254115.51.127.25516,382
207115.51.128.0/18115.51.128.1 to 115.51.191.254115.51.191.25516,382
208115.51.192.0/18115.51.192.1 to 115.51.255.254115.51.255.25516,382
209115.52.0.0/18115.52.0.1 to 115.52.63.254115.52.63.25516,382
210115.52.64.0/18115.52.64.1 to 115.52.127.254115.52.127.25516,382
211115.52.128.0/18115.52.128.1 to 115.52.191.254115.52.191.25516,382
212115.52.192.0/18115.52.192.1 to 115.52.255.254115.52.255.25516,382
213115.53.0.0/18115.53.0.1 to 115.53.63.254115.53.63.25516,382
214115.53.64.0/18115.53.64.1 to 115.53.127.254115.53.127.25516,382
215115.53.128.0/18115.53.128.1 to 115.53.191.254115.53.191.25516,382
216115.53.192.0/18115.53.192.1 to 115.53.255.254115.53.255.25516,382
217115.54.0.0/18115.54.0.1 to 115.54.63.254115.54.63.25516,382
218115.54.64.0/18115.54.64.1 to 115.54.127.254115.54.127.25516,382
219115.54.128.0/18115.54.128.1 to 115.54.191.254115.54.191.25516,382
220115.54.192.0/18115.54.192.1 to 115.54.255.254115.54.255.25516,382
221115.55.0.0/18115.55.0.1 to 115.55.63.254115.55.63.25516,382
222115.55.64.0/18115.55.64.1 to 115.55.127.254115.55.127.25516,382
223115.55.128.0/18115.55.128.1 to 115.55.191.254115.55.191.25516,382
224115.55.192.0/18115.55.192.1 to 115.55.255.254115.55.255.25516,382
225115.56.0.0/18115.56.0.1 to 115.56.63.254115.56.63.25516,382
226115.56.64.0/18115.56.64.1 to 115.56.127.254115.56.127.25516,382
227115.56.128.0/18115.56.128.1 to 115.56.191.254115.56.191.25516,382
228115.56.192.0/18115.56.192.1 to 115.56.255.254115.56.255.25516,382
229115.57.0.0/18115.57.0.1 to 115.57.63.254115.57.63.25516,382
230115.57.64.0/18115.57.64.1 to 115.57.127.254115.57.127.25516,382
231115.57.128.0/18115.57.128.1 to 115.57.191.254115.57.191.25516,382
232115.57.192.0/18115.57.192.1 to 115.57.255.254115.57.255.25516,382
233115.58.0.0/18115.58.0.1 to 115.58.63.254115.58.63.25516,382
234115.58.64.0/18115.58.64.1 to 115.58.127.254115.58.127.25516,382
235115.58.128.0/18115.58.128.1 to 115.58.191.254115.58.191.25516,382
236115.58.192.0/18115.58.192.1 to 115.58.255.254115.58.255.25516,382
237115.59.0.0/18115.59.0.1 to 115.59.63.254115.59.63.25516,382
238115.59.64.0/18115.59.64.1 to 115.59.127.254115.59.127.25516,382
239115.59.128.0/18115.59.128.1 to 115.59.191.254115.59.191.25516,382
240115.59.192.0/18115.59.192.1 to 115.59.255.254115.59.255.25516,382
241115.60.0.0/18115.60.0.1 to 115.60.63.254115.60.63.25516,382
242115.60.64.0/18115.60.64.1 to 115.60.127.254115.60.127.25516,382
243115.60.128.0/18115.60.128.1 to 115.60.191.254115.60.191.25516,382
244115.60.192.0/18115.60.192.1 to 115.60.255.254115.60.255.25516,382
245115.61.0.0/18115.61.0.1 to 115.61.63.254115.61.63.25516,382
246115.61.64.0/18115.61.64.1 to 115.61.127.254115.61.127.25516,382
247115.61.128.0/18115.61.128.1 to 115.61.191.254115.61.191.25516,382
248115.61.192.0/18115.61.192.1 to 115.61.255.254115.61.255.25516,382
249115.62.0.0/18115.62.0.1 to 115.62.63.254115.62.63.25516,382
250115.62.64.0/18115.62.64.1 to 115.62.127.254115.62.127.25516,382
251115.62.128.0/18115.62.128.1 to 115.62.191.254115.62.191.25516,382
252115.62.192.0/18115.62.192.1 to 115.62.255.254115.62.255.25516,382
253115.63.0.0/18115.63.0.1 to 115.63.63.254115.63.63.25516,382
254115.63.64.0/18115.63.64.1 to 115.63.127.254115.63.127.25516,382
255115.63.128.0/18115.63.128.1 to 115.63.191.254115.63.191.25516,382
256115.63.192.0/18115.63.192.1 to 115.63.255.254115.63.255.25516,382

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.