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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.

Network153.166.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
153.166.0.0
Broadcast address
153.167.255.255
First usable
153.166.0.1
Last usable
153.167.255.254
Usable hosts
131,070 (131,072 less the network and broadcast addresses)
Subnet mask
255.254.0.0
Wildcard mask
0.1.255.255 (Cisco ACLs, OSPF)
Prefix length
/15
Type
Public public
Old class
B (default /16)
As numbers
Hex 99A60000 · Integer 2577793024 to 2577924095
Reverse DNS zones
166.153.in-addr.arpa
167.153.in-addr.arpa
/15 is not on a 8-bit boundary, so it takes 2 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10011001.10100110.00000000.00000000153.166.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network10011001.10100110.00000000.00000000153.166.0.0
Broadcast10011001.10100111.11111111.11111111153.167.255.255
Split into smaller subnets/26
/16 (2)/17 (4)/18 (8)/19 (16)/20 (32)/21 (64)/22 (128)/23 (256)/24 (512)/25 (1,024)/26 (2,048)/27 (4,096)

153.166.0.0/15 makes 2,048 subnets of /26; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1153.166.0.0/26153.166.0.1 to 153.166.0.62153.166.0.6362
2153.166.0.64/26153.166.0.65 to 153.166.0.126153.166.0.12762
3153.166.0.128/26153.166.0.129 to 153.166.0.190153.166.0.19162
4153.166.0.192/26153.166.0.193 to 153.166.0.254153.166.0.25562
5153.166.1.0/26153.166.1.1 to 153.166.1.62153.166.1.6362
6153.166.1.64/26153.166.1.65 to 153.166.1.126153.166.1.12762
7153.166.1.128/26153.166.1.129 to 153.166.1.190153.166.1.19162
8153.166.1.192/26153.166.1.193 to 153.166.1.254153.166.1.25562
9153.166.2.0/26153.166.2.1 to 153.166.2.62153.166.2.6362
10153.166.2.64/26153.166.2.65 to 153.166.2.126153.166.2.12762
11153.166.2.128/26153.166.2.129 to 153.166.2.190153.166.2.19162
12153.166.2.192/26153.166.2.193 to 153.166.2.254153.166.2.25562
13153.166.3.0/26153.166.3.1 to 153.166.3.62153.166.3.6362
14153.166.3.64/26153.166.3.65 to 153.166.3.126153.166.3.12762
15153.166.3.128/26153.166.3.129 to 153.166.3.190153.166.3.19162
16153.166.3.192/26153.166.3.193 to 153.166.3.254153.166.3.25562
17153.166.4.0/26153.166.4.1 to 153.166.4.62153.166.4.6362
18153.166.4.64/26153.166.4.65 to 153.166.4.126153.166.4.12762
19153.166.4.128/26153.166.4.129 to 153.166.4.190153.166.4.19162
20153.166.4.192/26153.166.4.193 to 153.166.4.254153.166.4.25562
21153.166.5.0/26153.166.5.1 to 153.166.5.62153.166.5.6362
22153.166.5.64/26153.166.5.65 to 153.166.5.126153.166.5.12762
23153.166.5.128/26153.166.5.129 to 153.166.5.190153.166.5.19162
24153.166.5.192/26153.166.5.193 to 153.166.5.254153.166.5.25562
25153.166.6.0/26153.166.6.1 to 153.166.6.62153.166.6.6362
26153.166.6.64/26153.166.6.65 to 153.166.6.126153.166.6.12762
27153.166.6.128/26153.166.6.129 to 153.166.6.190153.166.6.19162
28153.166.6.192/26153.166.6.193 to 153.166.6.254153.166.6.25562
29153.166.7.0/26153.166.7.1 to 153.166.7.62153.166.7.6362
30153.166.7.64/26153.166.7.65 to 153.166.7.126153.166.7.12762
31153.166.7.128/26153.166.7.129 to 153.166.7.190153.166.7.19162
32153.166.7.192/26153.166.7.193 to 153.166.7.254153.166.7.25562
33153.166.8.0/26153.166.8.1 to 153.166.8.62153.166.8.6362
34153.166.8.64/26153.166.8.65 to 153.166.8.126153.166.8.12762
35153.166.8.128/26153.166.8.129 to 153.166.8.190153.166.8.19162
36153.166.8.192/26153.166.8.193 to 153.166.8.254153.166.8.25562
37153.166.9.0/26153.166.9.1 to 153.166.9.62153.166.9.6362
38153.166.9.64/26153.166.9.65 to 153.166.9.126153.166.9.12762
39153.166.9.128/26153.166.9.129 to 153.166.9.190153.166.9.19162
40153.166.9.192/26153.166.9.193 to 153.166.9.254153.166.9.25562
41153.166.10.0/26153.166.10.1 to 153.166.10.62153.166.10.6362
42153.166.10.64/26153.166.10.65 to 153.166.10.126153.166.10.12762
43153.166.10.128/26153.166.10.129 to 153.166.10.190153.166.10.19162
44153.166.10.192/26153.166.10.193 to 153.166.10.254153.166.10.25562
45153.166.11.0/26153.166.11.1 to 153.166.11.62153.166.11.6362
46153.166.11.64/26153.166.11.65 to 153.166.11.126153.166.11.12762
47153.166.11.128/26153.166.11.129 to 153.166.11.190153.166.11.19162
48153.166.11.192/26153.166.11.193 to 153.166.11.254153.166.11.25562
49153.166.12.0/26153.166.12.1 to 153.166.12.62153.166.12.6362
50153.166.12.64/26153.166.12.65 to 153.166.12.126153.166.12.12762
51153.166.12.128/26153.166.12.129 to 153.166.12.190153.166.12.19162
52153.166.12.192/26153.166.12.193 to 153.166.12.254153.166.12.25562
53153.166.13.0/26153.166.13.1 to 153.166.13.62153.166.13.6362
54153.166.13.64/26153.166.13.65 to 153.166.13.126153.166.13.12762
55153.166.13.128/26153.166.13.129 to 153.166.13.190153.166.13.19162
56153.166.13.192/26153.166.13.193 to 153.166.13.254153.166.13.25562
57153.166.14.0/26153.166.14.1 to 153.166.14.62153.166.14.6362
58153.166.14.64/26153.166.14.65 to 153.166.14.126153.166.14.12762
59153.166.14.128/26153.166.14.129 to 153.166.14.190153.166.14.19162
60153.166.14.192/26153.166.14.193 to 153.166.14.254153.166.14.25562
61153.166.15.0/26153.166.15.1 to 153.166.15.62153.166.15.6362
62153.166.15.64/26153.166.15.65 to 153.166.15.126153.166.15.12762
63153.166.15.128/26153.166.15.129 to 153.166.15.190153.166.15.19162
64153.166.15.192/26153.166.15.193 to 153.166.15.254153.166.15.25562
65153.166.16.0/26153.166.16.1 to 153.166.16.62153.166.16.6362
66153.166.16.64/26153.166.16.65 to 153.166.16.126153.166.16.12762
67153.166.16.128/26153.166.16.129 to 153.166.16.190153.166.16.19162
68153.166.16.192/26153.166.16.193 to 153.166.16.254153.166.16.25562
69153.166.17.0/26153.166.17.1 to 153.166.17.62153.166.17.6362
70153.166.17.64/26153.166.17.65 to 153.166.17.126153.166.17.12762
71153.166.17.128/26153.166.17.129 to 153.166.17.190153.166.17.19162
72153.166.17.192/26153.166.17.193 to 153.166.17.254153.166.17.25562
73153.166.18.0/26153.166.18.1 to 153.166.18.62153.166.18.6362
74153.166.18.64/26153.166.18.65 to 153.166.18.126153.166.18.12762
75153.166.18.128/26153.166.18.129 to 153.166.18.190153.166.18.19162
76153.166.18.192/26153.166.18.193 to 153.166.18.254153.166.18.25562
77153.166.19.0/26153.166.19.1 to 153.166.19.62153.166.19.6362
78153.166.19.64/26153.166.19.65 to 153.166.19.126153.166.19.12762
79153.166.19.128/26153.166.19.129 to 153.166.19.190153.166.19.19162
80153.166.19.192/26153.166.19.193 to 153.166.19.254153.166.19.25562
81153.166.20.0/26153.166.20.1 to 153.166.20.62153.166.20.6362
82153.166.20.64/26153.166.20.65 to 153.166.20.126153.166.20.12762
83153.166.20.128/26153.166.20.129 to 153.166.20.190153.166.20.19162
84153.166.20.192/26153.166.20.193 to 153.166.20.254153.166.20.25562
85153.166.21.0/26153.166.21.1 to 153.166.21.62153.166.21.6362
86153.166.21.64/26153.166.21.65 to 153.166.21.126153.166.21.12762
87153.166.21.128/26153.166.21.129 to 153.166.21.190153.166.21.19162
88153.166.21.192/26153.166.21.193 to 153.166.21.254153.166.21.25562
89153.166.22.0/26153.166.22.1 to 153.166.22.62153.166.22.6362
90153.166.22.64/26153.166.22.65 to 153.166.22.126153.166.22.12762
91153.166.22.128/26153.166.22.129 to 153.166.22.190153.166.22.19162
92153.166.22.192/26153.166.22.193 to 153.166.22.254153.166.22.25562
93153.166.23.0/26153.166.23.1 to 153.166.23.62153.166.23.6362
94153.166.23.64/26153.166.23.65 to 153.166.23.126153.166.23.12762
95153.166.23.128/26153.166.23.129 to 153.166.23.190153.166.23.19162
96153.166.23.192/26153.166.23.193 to 153.166.23.254153.166.23.25562
97153.166.24.0/26153.166.24.1 to 153.166.24.62153.166.24.6362
98153.166.24.64/26153.166.24.65 to 153.166.24.126153.166.24.12762
99153.166.24.128/26153.166.24.129 to 153.166.24.190153.166.24.19162
100153.166.24.192/26153.166.24.193 to 153.166.24.254153.166.24.25562
101153.166.25.0/26153.166.25.1 to 153.166.25.62153.166.25.6362
102153.166.25.64/26153.166.25.65 to 153.166.25.126153.166.25.12762
103153.166.25.128/26153.166.25.129 to 153.166.25.190153.166.25.19162
104153.166.25.192/26153.166.25.193 to 153.166.25.254153.166.25.25562
105153.166.26.0/26153.166.26.1 to 153.166.26.62153.166.26.6362
106153.166.26.64/26153.166.26.65 to 153.166.26.126153.166.26.12762
107153.166.26.128/26153.166.26.129 to 153.166.26.190153.166.26.19162
108153.166.26.192/26153.166.26.193 to 153.166.26.254153.166.26.25562
109153.166.27.0/26153.166.27.1 to 153.166.27.62153.166.27.6362
110153.166.27.64/26153.166.27.65 to 153.166.27.126153.166.27.12762
111153.166.27.128/26153.166.27.129 to 153.166.27.190153.166.27.19162
112153.166.27.192/26153.166.27.193 to 153.166.27.254153.166.27.25562
113153.166.28.0/26153.166.28.1 to 153.166.28.62153.166.28.6362
114153.166.28.64/26153.166.28.65 to 153.166.28.126153.166.28.12762
115153.166.28.128/26153.166.28.129 to 153.166.28.190153.166.28.19162
116153.166.28.192/26153.166.28.193 to 153.166.28.254153.166.28.25562
117153.166.29.0/26153.166.29.1 to 153.166.29.62153.166.29.6362
118153.166.29.64/26153.166.29.65 to 153.166.29.126153.166.29.12762
119153.166.29.128/26153.166.29.129 to 153.166.29.190153.166.29.19162
120153.166.29.192/26153.166.29.193 to 153.166.29.254153.166.29.25562
121153.166.30.0/26153.166.30.1 to 153.166.30.62153.166.30.6362
122153.166.30.64/26153.166.30.65 to 153.166.30.126153.166.30.12762
123153.166.30.128/26153.166.30.129 to 153.166.30.190153.166.30.19162
124153.166.30.192/26153.166.30.193 to 153.166.30.254153.166.30.25562
125153.166.31.0/26153.166.31.1 to 153.166.31.62153.166.31.6362
126153.166.31.64/26153.166.31.65 to 153.166.31.126153.166.31.12762
127153.166.31.128/26153.166.31.129 to 153.166.31.190153.166.31.19162
128153.166.31.192/26153.166.31.193 to 153.166.31.254153.166.31.25562
129153.166.32.0/26153.166.32.1 to 153.166.32.62153.166.32.6362
130153.166.32.64/26153.166.32.65 to 153.166.32.126153.166.32.12762
131153.166.32.128/26153.166.32.129 to 153.166.32.190153.166.32.19162
132153.166.32.192/26153.166.32.193 to 153.166.32.254153.166.32.25562
133153.166.33.0/26153.166.33.1 to 153.166.33.62153.166.33.6362
134153.166.33.64/26153.166.33.65 to 153.166.33.126153.166.33.12762
135153.166.33.128/26153.166.33.129 to 153.166.33.190153.166.33.19162
136153.166.33.192/26153.166.33.193 to 153.166.33.254153.166.33.25562
137153.166.34.0/26153.166.34.1 to 153.166.34.62153.166.34.6362
138153.166.34.64/26153.166.34.65 to 153.166.34.126153.166.34.12762
139153.166.34.128/26153.166.34.129 to 153.166.34.190153.166.34.19162
140153.166.34.192/26153.166.34.193 to 153.166.34.254153.166.34.25562
141153.166.35.0/26153.166.35.1 to 153.166.35.62153.166.35.6362
142153.166.35.64/26153.166.35.65 to 153.166.35.126153.166.35.12762
143153.166.35.128/26153.166.35.129 to 153.166.35.190153.166.35.19162
144153.166.35.192/26153.166.35.193 to 153.166.35.254153.166.35.25562
145153.166.36.0/26153.166.36.1 to 153.166.36.62153.166.36.6362
146153.166.36.64/26153.166.36.65 to 153.166.36.126153.166.36.12762
147153.166.36.128/26153.166.36.129 to 153.166.36.190153.166.36.19162
148153.166.36.192/26153.166.36.193 to 153.166.36.254153.166.36.25562
149153.166.37.0/26153.166.37.1 to 153.166.37.62153.166.37.6362
150153.166.37.64/26153.166.37.65 to 153.166.37.126153.166.37.12762
151153.166.37.128/26153.166.37.129 to 153.166.37.190153.166.37.19162
152153.166.37.192/26153.166.37.193 to 153.166.37.254153.166.37.25562
153153.166.38.0/26153.166.38.1 to 153.166.38.62153.166.38.6362
154153.166.38.64/26153.166.38.65 to 153.166.38.126153.166.38.12762
155153.166.38.128/26153.166.38.129 to 153.166.38.190153.166.38.19162
156153.166.38.192/26153.166.38.193 to 153.166.38.254153.166.38.25562
157153.166.39.0/26153.166.39.1 to 153.166.39.62153.166.39.6362
158153.166.39.64/26153.166.39.65 to 153.166.39.126153.166.39.12762
159153.166.39.128/26153.166.39.129 to 153.166.39.190153.166.39.19162
160153.166.39.192/26153.166.39.193 to 153.166.39.254153.166.39.25562
161153.166.40.0/26153.166.40.1 to 153.166.40.62153.166.40.6362
162153.166.40.64/26153.166.40.65 to 153.166.40.126153.166.40.12762
163153.166.40.128/26153.166.40.129 to 153.166.40.190153.166.40.19162
164153.166.40.192/26153.166.40.193 to 153.166.40.254153.166.40.25562
165153.166.41.0/26153.166.41.1 to 153.166.41.62153.166.41.6362
166153.166.41.64/26153.166.41.65 to 153.166.41.126153.166.41.12762
167153.166.41.128/26153.166.41.129 to 153.166.41.190153.166.41.19162
168153.166.41.192/26153.166.41.193 to 153.166.41.254153.166.41.25562
169153.166.42.0/26153.166.42.1 to 153.166.42.62153.166.42.6362
170153.166.42.64/26153.166.42.65 to 153.166.42.126153.166.42.12762
171153.166.42.128/26153.166.42.129 to 153.166.42.190153.166.42.19162
172153.166.42.192/26153.166.42.193 to 153.166.42.254153.166.42.25562
173153.166.43.0/26153.166.43.1 to 153.166.43.62153.166.43.6362
174153.166.43.64/26153.166.43.65 to 153.166.43.126153.166.43.12762
175153.166.43.128/26153.166.43.129 to 153.166.43.190153.166.43.19162
176153.166.43.192/26153.166.43.193 to 153.166.43.254153.166.43.25562
177153.166.44.0/26153.166.44.1 to 153.166.44.62153.166.44.6362
178153.166.44.64/26153.166.44.65 to 153.166.44.126153.166.44.12762
179153.166.44.128/26153.166.44.129 to 153.166.44.190153.166.44.19162
180153.166.44.192/26153.166.44.193 to 153.166.44.254153.166.44.25562
181153.166.45.0/26153.166.45.1 to 153.166.45.62153.166.45.6362
182153.166.45.64/26153.166.45.65 to 153.166.45.126153.166.45.12762
183153.166.45.128/26153.166.45.129 to 153.166.45.190153.166.45.19162
184153.166.45.192/26153.166.45.193 to 153.166.45.254153.166.45.25562
185153.166.46.0/26153.166.46.1 to 153.166.46.62153.166.46.6362
186153.166.46.64/26153.166.46.65 to 153.166.46.126153.166.46.12762
187153.166.46.128/26153.166.46.129 to 153.166.46.190153.166.46.19162
188153.166.46.192/26153.166.46.193 to 153.166.46.254153.166.46.25562
189153.166.47.0/26153.166.47.1 to 153.166.47.62153.166.47.6362
190153.166.47.64/26153.166.47.65 to 153.166.47.126153.166.47.12762
191153.166.47.128/26153.166.47.129 to 153.166.47.190153.166.47.19162
192153.166.47.192/26153.166.47.193 to 153.166.47.254153.166.47.25562
193153.166.48.0/26153.166.48.1 to 153.166.48.62153.166.48.6362
194153.166.48.64/26153.166.48.65 to 153.166.48.126153.166.48.12762
195153.166.48.128/26153.166.48.129 to 153.166.48.190153.166.48.19162
196153.166.48.192/26153.166.48.193 to 153.166.48.254153.166.48.25562
197153.166.49.0/26153.166.49.1 to 153.166.49.62153.166.49.6362
198153.166.49.64/26153.166.49.65 to 153.166.49.126153.166.49.12762
199153.166.49.128/26153.166.49.129 to 153.166.49.190153.166.49.19162
200153.166.49.192/26153.166.49.193 to 153.166.49.254153.166.49.25562
201153.166.50.0/26153.166.50.1 to 153.166.50.62153.166.50.6362
202153.166.50.64/26153.166.50.65 to 153.166.50.126153.166.50.12762
203153.166.50.128/26153.166.50.129 to 153.166.50.190153.166.50.19162
204153.166.50.192/26153.166.50.193 to 153.166.50.254153.166.50.25562
205153.166.51.0/26153.166.51.1 to 153.166.51.62153.166.51.6362
206153.166.51.64/26153.166.51.65 to 153.166.51.126153.166.51.12762
207153.166.51.128/26153.166.51.129 to 153.166.51.190153.166.51.19162
208153.166.51.192/26153.166.51.193 to 153.166.51.254153.166.51.25562
209153.166.52.0/26153.166.52.1 to 153.166.52.62153.166.52.6362
210153.166.52.64/26153.166.52.65 to 153.166.52.126153.166.52.12762
211153.166.52.128/26153.166.52.129 to 153.166.52.190153.166.52.19162
212153.166.52.192/26153.166.52.193 to 153.166.52.254153.166.52.25562
213153.166.53.0/26153.166.53.1 to 153.166.53.62153.166.53.6362
214153.166.53.64/26153.166.53.65 to 153.166.53.126153.166.53.12762
215153.166.53.128/26153.166.53.129 to 153.166.53.190153.166.53.19162
216153.166.53.192/26153.166.53.193 to 153.166.53.254153.166.53.25562
217153.166.54.0/26153.166.54.1 to 153.166.54.62153.166.54.6362
218153.166.54.64/26153.166.54.65 to 153.166.54.126153.166.54.12762
219153.166.54.128/26153.166.54.129 to 153.166.54.190153.166.54.19162
220153.166.54.192/26153.166.54.193 to 153.166.54.254153.166.54.25562
221153.166.55.0/26153.166.55.1 to 153.166.55.62153.166.55.6362
222153.166.55.64/26153.166.55.65 to 153.166.55.126153.166.55.12762
223153.166.55.128/26153.166.55.129 to 153.166.55.190153.166.55.19162
224153.166.55.192/26153.166.55.193 to 153.166.55.254153.166.55.25562
225153.166.56.0/26153.166.56.1 to 153.166.56.62153.166.56.6362
226153.166.56.64/26153.166.56.65 to 153.166.56.126153.166.56.12762
227153.166.56.128/26153.166.56.129 to 153.166.56.190153.166.56.19162
228153.166.56.192/26153.166.56.193 to 153.166.56.254153.166.56.25562
229153.166.57.0/26153.166.57.1 to 153.166.57.62153.166.57.6362
230153.166.57.64/26153.166.57.65 to 153.166.57.126153.166.57.12762
231153.166.57.128/26153.166.57.129 to 153.166.57.190153.166.57.19162
232153.166.57.192/26153.166.57.193 to 153.166.57.254153.166.57.25562
233153.166.58.0/26153.166.58.1 to 153.166.58.62153.166.58.6362
234153.166.58.64/26153.166.58.65 to 153.166.58.126153.166.58.12762
235153.166.58.128/26153.166.58.129 to 153.166.58.190153.166.58.19162
236153.166.58.192/26153.166.58.193 to 153.166.58.254153.166.58.25562
237153.166.59.0/26153.166.59.1 to 153.166.59.62153.166.59.6362
238153.166.59.64/26153.166.59.65 to 153.166.59.126153.166.59.12762
239153.166.59.128/26153.166.59.129 to 153.166.59.190153.166.59.19162
240153.166.59.192/26153.166.59.193 to 153.166.59.254153.166.59.25562
241153.166.60.0/26153.166.60.1 to 153.166.60.62153.166.60.6362
242153.166.60.64/26153.166.60.65 to 153.166.60.126153.166.60.12762
243153.166.60.128/26153.166.60.129 to 153.166.60.190153.166.60.19162
244153.166.60.192/26153.166.60.193 to 153.166.60.254153.166.60.25562
245153.166.61.0/26153.166.61.1 to 153.166.61.62153.166.61.6362
246153.166.61.64/26153.166.61.65 to 153.166.61.126153.166.61.12762
247153.166.61.128/26153.166.61.129 to 153.166.61.190153.166.61.19162
248153.166.61.192/26153.166.61.193 to 153.166.61.254153.166.61.25562
249153.166.62.0/26153.166.62.1 to 153.166.62.62153.166.62.6362
250153.166.62.64/26153.166.62.65 to 153.166.62.126153.166.62.12762
251153.166.62.128/26153.166.62.129 to 153.166.62.190153.166.62.19162
252153.166.62.192/26153.166.62.193 to 153.166.62.254153.166.62.25562
253153.166.63.0/26153.166.63.1 to 153.166.63.62153.166.63.6362
254153.166.63.64/26153.166.63.65 to 153.166.63.126153.166.63.12762
255153.166.63.128/26153.166.63.129 to 153.166.63.190153.166.63.19162
256153.166.63.192/26153.166.63.193 to 153.166.63.254153.166.63.25562

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.