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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.

Network137.136.0.0/14
Usable hosts262,142
Subnet mask255.252.0.0
Addresses262,144
Network address
137.136.0.0
Broadcast address
137.139.255.255
First usable
137.136.0.1
Last usable
137.139.255.254
Usable hosts
262,142 (262,144 less the network and broadcast addresses)
Subnet mask
255.252.0.0
Wildcard mask
0.3.255.255 (Cisco ACLs, OSPF)
Prefix length
/14
Type
Public public
Old class
B (default /16)
As numbers
Hex 89880000 · Integer 2307391488 to 2307653631
Reverse DNS zones
136.137.in-addr.arpa
137.137.in-addr.arpa
138.137.in-addr.arpa
139.137.in-addr.arpa
/14 is not on a 8-bit boundary, so it takes 4 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10001001.10001000.00000000.00000000137.136.0.0
Subnet mask11111111.11111100.00000000.00000000255.252.0.0
Network10001001.10001000.00000000.00000000137.136.0.0
Broadcast10001001.10001011.11111111.11111111137.139.255.255
Split into smaller subnets/26
/15 (2)/16 (4)/17 (8)/18 (16)/19 (32)/20 (64)/21 (128)/22 (256)/23 (512)/24 (1,024)/25 (2,048)/26 (4,096)

137.136.0.0/14 makes 4,096 subnets of /26; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1137.136.0.0/26137.136.0.1 to 137.136.0.62137.136.0.6362
2137.136.0.64/26137.136.0.65 to 137.136.0.126137.136.0.12762
3137.136.0.128/26137.136.0.129 to 137.136.0.190137.136.0.19162
4137.136.0.192/26137.136.0.193 to 137.136.0.254137.136.0.25562
5137.136.1.0/26137.136.1.1 to 137.136.1.62137.136.1.6362
6137.136.1.64/26137.136.1.65 to 137.136.1.126137.136.1.12762
7137.136.1.128/26137.136.1.129 to 137.136.1.190137.136.1.19162
8137.136.1.192/26137.136.1.193 to 137.136.1.254137.136.1.25562
9137.136.2.0/26137.136.2.1 to 137.136.2.62137.136.2.6362
10137.136.2.64/26137.136.2.65 to 137.136.2.126137.136.2.12762
11137.136.2.128/26137.136.2.129 to 137.136.2.190137.136.2.19162
12137.136.2.192/26137.136.2.193 to 137.136.2.254137.136.2.25562
13137.136.3.0/26137.136.3.1 to 137.136.3.62137.136.3.6362
14137.136.3.64/26137.136.3.65 to 137.136.3.126137.136.3.12762
15137.136.3.128/26137.136.3.129 to 137.136.3.190137.136.3.19162
16137.136.3.192/26137.136.3.193 to 137.136.3.254137.136.3.25562
17137.136.4.0/26137.136.4.1 to 137.136.4.62137.136.4.6362
18137.136.4.64/26137.136.4.65 to 137.136.4.126137.136.4.12762
19137.136.4.128/26137.136.4.129 to 137.136.4.190137.136.4.19162
20137.136.4.192/26137.136.4.193 to 137.136.4.254137.136.4.25562
21137.136.5.0/26137.136.5.1 to 137.136.5.62137.136.5.6362
22137.136.5.64/26137.136.5.65 to 137.136.5.126137.136.5.12762
23137.136.5.128/26137.136.5.129 to 137.136.5.190137.136.5.19162
24137.136.5.192/26137.136.5.193 to 137.136.5.254137.136.5.25562
25137.136.6.0/26137.136.6.1 to 137.136.6.62137.136.6.6362
26137.136.6.64/26137.136.6.65 to 137.136.6.126137.136.6.12762
27137.136.6.128/26137.136.6.129 to 137.136.6.190137.136.6.19162
28137.136.6.192/26137.136.6.193 to 137.136.6.254137.136.6.25562
29137.136.7.0/26137.136.7.1 to 137.136.7.62137.136.7.6362
30137.136.7.64/26137.136.7.65 to 137.136.7.126137.136.7.12762
31137.136.7.128/26137.136.7.129 to 137.136.7.190137.136.7.19162
32137.136.7.192/26137.136.7.193 to 137.136.7.254137.136.7.25562
33137.136.8.0/26137.136.8.1 to 137.136.8.62137.136.8.6362
34137.136.8.64/26137.136.8.65 to 137.136.8.126137.136.8.12762
35137.136.8.128/26137.136.8.129 to 137.136.8.190137.136.8.19162
36137.136.8.192/26137.136.8.193 to 137.136.8.254137.136.8.25562
37137.136.9.0/26137.136.9.1 to 137.136.9.62137.136.9.6362
38137.136.9.64/26137.136.9.65 to 137.136.9.126137.136.9.12762
39137.136.9.128/26137.136.9.129 to 137.136.9.190137.136.9.19162
40137.136.9.192/26137.136.9.193 to 137.136.9.254137.136.9.25562
41137.136.10.0/26137.136.10.1 to 137.136.10.62137.136.10.6362
42137.136.10.64/26137.136.10.65 to 137.136.10.126137.136.10.12762
43137.136.10.128/26137.136.10.129 to 137.136.10.190137.136.10.19162
44137.136.10.192/26137.136.10.193 to 137.136.10.254137.136.10.25562
45137.136.11.0/26137.136.11.1 to 137.136.11.62137.136.11.6362
46137.136.11.64/26137.136.11.65 to 137.136.11.126137.136.11.12762
47137.136.11.128/26137.136.11.129 to 137.136.11.190137.136.11.19162
48137.136.11.192/26137.136.11.193 to 137.136.11.254137.136.11.25562
49137.136.12.0/26137.136.12.1 to 137.136.12.62137.136.12.6362
50137.136.12.64/26137.136.12.65 to 137.136.12.126137.136.12.12762
51137.136.12.128/26137.136.12.129 to 137.136.12.190137.136.12.19162
52137.136.12.192/26137.136.12.193 to 137.136.12.254137.136.12.25562
53137.136.13.0/26137.136.13.1 to 137.136.13.62137.136.13.6362
54137.136.13.64/26137.136.13.65 to 137.136.13.126137.136.13.12762
55137.136.13.128/26137.136.13.129 to 137.136.13.190137.136.13.19162
56137.136.13.192/26137.136.13.193 to 137.136.13.254137.136.13.25562
57137.136.14.0/26137.136.14.1 to 137.136.14.62137.136.14.6362
58137.136.14.64/26137.136.14.65 to 137.136.14.126137.136.14.12762
59137.136.14.128/26137.136.14.129 to 137.136.14.190137.136.14.19162
60137.136.14.192/26137.136.14.193 to 137.136.14.254137.136.14.25562
61137.136.15.0/26137.136.15.1 to 137.136.15.62137.136.15.6362
62137.136.15.64/26137.136.15.65 to 137.136.15.126137.136.15.12762
63137.136.15.128/26137.136.15.129 to 137.136.15.190137.136.15.19162
64137.136.15.192/26137.136.15.193 to 137.136.15.254137.136.15.25562
65137.136.16.0/26137.136.16.1 to 137.136.16.62137.136.16.6362
66137.136.16.64/26137.136.16.65 to 137.136.16.126137.136.16.12762
67137.136.16.128/26137.136.16.129 to 137.136.16.190137.136.16.19162
68137.136.16.192/26137.136.16.193 to 137.136.16.254137.136.16.25562
69137.136.17.0/26137.136.17.1 to 137.136.17.62137.136.17.6362
70137.136.17.64/26137.136.17.65 to 137.136.17.126137.136.17.12762
71137.136.17.128/26137.136.17.129 to 137.136.17.190137.136.17.19162
72137.136.17.192/26137.136.17.193 to 137.136.17.254137.136.17.25562
73137.136.18.0/26137.136.18.1 to 137.136.18.62137.136.18.6362
74137.136.18.64/26137.136.18.65 to 137.136.18.126137.136.18.12762
75137.136.18.128/26137.136.18.129 to 137.136.18.190137.136.18.19162
76137.136.18.192/26137.136.18.193 to 137.136.18.254137.136.18.25562
77137.136.19.0/26137.136.19.1 to 137.136.19.62137.136.19.6362
78137.136.19.64/26137.136.19.65 to 137.136.19.126137.136.19.12762
79137.136.19.128/26137.136.19.129 to 137.136.19.190137.136.19.19162
80137.136.19.192/26137.136.19.193 to 137.136.19.254137.136.19.25562
81137.136.20.0/26137.136.20.1 to 137.136.20.62137.136.20.6362
82137.136.20.64/26137.136.20.65 to 137.136.20.126137.136.20.12762
83137.136.20.128/26137.136.20.129 to 137.136.20.190137.136.20.19162
84137.136.20.192/26137.136.20.193 to 137.136.20.254137.136.20.25562
85137.136.21.0/26137.136.21.1 to 137.136.21.62137.136.21.6362
86137.136.21.64/26137.136.21.65 to 137.136.21.126137.136.21.12762
87137.136.21.128/26137.136.21.129 to 137.136.21.190137.136.21.19162
88137.136.21.192/26137.136.21.193 to 137.136.21.254137.136.21.25562
89137.136.22.0/26137.136.22.1 to 137.136.22.62137.136.22.6362
90137.136.22.64/26137.136.22.65 to 137.136.22.126137.136.22.12762
91137.136.22.128/26137.136.22.129 to 137.136.22.190137.136.22.19162
92137.136.22.192/26137.136.22.193 to 137.136.22.254137.136.22.25562
93137.136.23.0/26137.136.23.1 to 137.136.23.62137.136.23.6362
94137.136.23.64/26137.136.23.65 to 137.136.23.126137.136.23.12762
95137.136.23.128/26137.136.23.129 to 137.136.23.190137.136.23.19162
96137.136.23.192/26137.136.23.193 to 137.136.23.254137.136.23.25562
97137.136.24.0/26137.136.24.1 to 137.136.24.62137.136.24.6362
98137.136.24.64/26137.136.24.65 to 137.136.24.126137.136.24.12762
99137.136.24.128/26137.136.24.129 to 137.136.24.190137.136.24.19162
100137.136.24.192/26137.136.24.193 to 137.136.24.254137.136.24.25562
101137.136.25.0/26137.136.25.1 to 137.136.25.62137.136.25.6362
102137.136.25.64/26137.136.25.65 to 137.136.25.126137.136.25.12762
103137.136.25.128/26137.136.25.129 to 137.136.25.190137.136.25.19162
104137.136.25.192/26137.136.25.193 to 137.136.25.254137.136.25.25562
105137.136.26.0/26137.136.26.1 to 137.136.26.62137.136.26.6362
106137.136.26.64/26137.136.26.65 to 137.136.26.126137.136.26.12762
107137.136.26.128/26137.136.26.129 to 137.136.26.190137.136.26.19162
108137.136.26.192/26137.136.26.193 to 137.136.26.254137.136.26.25562
109137.136.27.0/26137.136.27.1 to 137.136.27.62137.136.27.6362
110137.136.27.64/26137.136.27.65 to 137.136.27.126137.136.27.12762
111137.136.27.128/26137.136.27.129 to 137.136.27.190137.136.27.19162
112137.136.27.192/26137.136.27.193 to 137.136.27.254137.136.27.25562
113137.136.28.0/26137.136.28.1 to 137.136.28.62137.136.28.6362
114137.136.28.64/26137.136.28.65 to 137.136.28.126137.136.28.12762
115137.136.28.128/26137.136.28.129 to 137.136.28.190137.136.28.19162
116137.136.28.192/26137.136.28.193 to 137.136.28.254137.136.28.25562
117137.136.29.0/26137.136.29.1 to 137.136.29.62137.136.29.6362
118137.136.29.64/26137.136.29.65 to 137.136.29.126137.136.29.12762
119137.136.29.128/26137.136.29.129 to 137.136.29.190137.136.29.19162
120137.136.29.192/26137.136.29.193 to 137.136.29.254137.136.29.25562
121137.136.30.0/26137.136.30.1 to 137.136.30.62137.136.30.6362
122137.136.30.64/26137.136.30.65 to 137.136.30.126137.136.30.12762
123137.136.30.128/26137.136.30.129 to 137.136.30.190137.136.30.19162
124137.136.30.192/26137.136.30.193 to 137.136.30.254137.136.30.25562
125137.136.31.0/26137.136.31.1 to 137.136.31.62137.136.31.6362
126137.136.31.64/26137.136.31.65 to 137.136.31.126137.136.31.12762
127137.136.31.128/26137.136.31.129 to 137.136.31.190137.136.31.19162
128137.136.31.192/26137.136.31.193 to 137.136.31.254137.136.31.25562
129137.136.32.0/26137.136.32.1 to 137.136.32.62137.136.32.6362
130137.136.32.64/26137.136.32.65 to 137.136.32.126137.136.32.12762
131137.136.32.128/26137.136.32.129 to 137.136.32.190137.136.32.19162
132137.136.32.192/26137.136.32.193 to 137.136.32.254137.136.32.25562
133137.136.33.0/26137.136.33.1 to 137.136.33.62137.136.33.6362
134137.136.33.64/26137.136.33.65 to 137.136.33.126137.136.33.12762
135137.136.33.128/26137.136.33.129 to 137.136.33.190137.136.33.19162
136137.136.33.192/26137.136.33.193 to 137.136.33.254137.136.33.25562
137137.136.34.0/26137.136.34.1 to 137.136.34.62137.136.34.6362
138137.136.34.64/26137.136.34.65 to 137.136.34.126137.136.34.12762
139137.136.34.128/26137.136.34.129 to 137.136.34.190137.136.34.19162
140137.136.34.192/26137.136.34.193 to 137.136.34.254137.136.34.25562
141137.136.35.0/26137.136.35.1 to 137.136.35.62137.136.35.6362
142137.136.35.64/26137.136.35.65 to 137.136.35.126137.136.35.12762
143137.136.35.128/26137.136.35.129 to 137.136.35.190137.136.35.19162
144137.136.35.192/26137.136.35.193 to 137.136.35.254137.136.35.25562
145137.136.36.0/26137.136.36.1 to 137.136.36.62137.136.36.6362
146137.136.36.64/26137.136.36.65 to 137.136.36.126137.136.36.12762
147137.136.36.128/26137.136.36.129 to 137.136.36.190137.136.36.19162
148137.136.36.192/26137.136.36.193 to 137.136.36.254137.136.36.25562
149137.136.37.0/26137.136.37.1 to 137.136.37.62137.136.37.6362
150137.136.37.64/26137.136.37.65 to 137.136.37.126137.136.37.12762
151137.136.37.128/26137.136.37.129 to 137.136.37.190137.136.37.19162
152137.136.37.192/26137.136.37.193 to 137.136.37.254137.136.37.25562
153137.136.38.0/26137.136.38.1 to 137.136.38.62137.136.38.6362
154137.136.38.64/26137.136.38.65 to 137.136.38.126137.136.38.12762
155137.136.38.128/26137.136.38.129 to 137.136.38.190137.136.38.19162
156137.136.38.192/26137.136.38.193 to 137.136.38.254137.136.38.25562
157137.136.39.0/26137.136.39.1 to 137.136.39.62137.136.39.6362
158137.136.39.64/26137.136.39.65 to 137.136.39.126137.136.39.12762
159137.136.39.128/26137.136.39.129 to 137.136.39.190137.136.39.19162
160137.136.39.192/26137.136.39.193 to 137.136.39.254137.136.39.25562
161137.136.40.0/26137.136.40.1 to 137.136.40.62137.136.40.6362
162137.136.40.64/26137.136.40.65 to 137.136.40.126137.136.40.12762
163137.136.40.128/26137.136.40.129 to 137.136.40.190137.136.40.19162
164137.136.40.192/26137.136.40.193 to 137.136.40.254137.136.40.25562
165137.136.41.0/26137.136.41.1 to 137.136.41.62137.136.41.6362
166137.136.41.64/26137.136.41.65 to 137.136.41.126137.136.41.12762
167137.136.41.128/26137.136.41.129 to 137.136.41.190137.136.41.19162
168137.136.41.192/26137.136.41.193 to 137.136.41.254137.136.41.25562
169137.136.42.0/26137.136.42.1 to 137.136.42.62137.136.42.6362
170137.136.42.64/26137.136.42.65 to 137.136.42.126137.136.42.12762
171137.136.42.128/26137.136.42.129 to 137.136.42.190137.136.42.19162
172137.136.42.192/26137.136.42.193 to 137.136.42.254137.136.42.25562
173137.136.43.0/26137.136.43.1 to 137.136.43.62137.136.43.6362
174137.136.43.64/26137.136.43.65 to 137.136.43.126137.136.43.12762
175137.136.43.128/26137.136.43.129 to 137.136.43.190137.136.43.19162
176137.136.43.192/26137.136.43.193 to 137.136.43.254137.136.43.25562
177137.136.44.0/26137.136.44.1 to 137.136.44.62137.136.44.6362
178137.136.44.64/26137.136.44.65 to 137.136.44.126137.136.44.12762
179137.136.44.128/26137.136.44.129 to 137.136.44.190137.136.44.19162
180137.136.44.192/26137.136.44.193 to 137.136.44.254137.136.44.25562
181137.136.45.0/26137.136.45.1 to 137.136.45.62137.136.45.6362
182137.136.45.64/26137.136.45.65 to 137.136.45.126137.136.45.12762
183137.136.45.128/26137.136.45.129 to 137.136.45.190137.136.45.19162
184137.136.45.192/26137.136.45.193 to 137.136.45.254137.136.45.25562
185137.136.46.0/26137.136.46.1 to 137.136.46.62137.136.46.6362
186137.136.46.64/26137.136.46.65 to 137.136.46.126137.136.46.12762
187137.136.46.128/26137.136.46.129 to 137.136.46.190137.136.46.19162
188137.136.46.192/26137.136.46.193 to 137.136.46.254137.136.46.25562
189137.136.47.0/26137.136.47.1 to 137.136.47.62137.136.47.6362
190137.136.47.64/26137.136.47.65 to 137.136.47.126137.136.47.12762
191137.136.47.128/26137.136.47.129 to 137.136.47.190137.136.47.19162
192137.136.47.192/26137.136.47.193 to 137.136.47.254137.136.47.25562
193137.136.48.0/26137.136.48.1 to 137.136.48.62137.136.48.6362
194137.136.48.64/26137.136.48.65 to 137.136.48.126137.136.48.12762
195137.136.48.128/26137.136.48.129 to 137.136.48.190137.136.48.19162
196137.136.48.192/26137.136.48.193 to 137.136.48.254137.136.48.25562
197137.136.49.0/26137.136.49.1 to 137.136.49.62137.136.49.6362
198137.136.49.64/26137.136.49.65 to 137.136.49.126137.136.49.12762
199137.136.49.128/26137.136.49.129 to 137.136.49.190137.136.49.19162
200137.136.49.192/26137.136.49.193 to 137.136.49.254137.136.49.25562
201137.136.50.0/26137.136.50.1 to 137.136.50.62137.136.50.6362
202137.136.50.64/26137.136.50.65 to 137.136.50.126137.136.50.12762
203137.136.50.128/26137.136.50.129 to 137.136.50.190137.136.50.19162
204137.136.50.192/26137.136.50.193 to 137.136.50.254137.136.50.25562
205137.136.51.0/26137.136.51.1 to 137.136.51.62137.136.51.6362
206137.136.51.64/26137.136.51.65 to 137.136.51.126137.136.51.12762
207137.136.51.128/26137.136.51.129 to 137.136.51.190137.136.51.19162
208137.136.51.192/26137.136.51.193 to 137.136.51.254137.136.51.25562
209137.136.52.0/26137.136.52.1 to 137.136.52.62137.136.52.6362
210137.136.52.64/26137.136.52.65 to 137.136.52.126137.136.52.12762
211137.136.52.128/26137.136.52.129 to 137.136.52.190137.136.52.19162
212137.136.52.192/26137.136.52.193 to 137.136.52.254137.136.52.25562
213137.136.53.0/26137.136.53.1 to 137.136.53.62137.136.53.6362
214137.136.53.64/26137.136.53.65 to 137.136.53.126137.136.53.12762
215137.136.53.128/26137.136.53.129 to 137.136.53.190137.136.53.19162
216137.136.53.192/26137.136.53.193 to 137.136.53.254137.136.53.25562
217137.136.54.0/26137.136.54.1 to 137.136.54.62137.136.54.6362
218137.136.54.64/26137.136.54.65 to 137.136.54.126137.136.54.12762
219137.136.54.128/26137.136.54.129 to 137.136.54.190137.136.54.19162
220137.136.54.192/26137.136.54.193 to 137.136.54.254137.136.54.25562
221137.136.55.0/26137.136.55.1 to 137.136.55.62137.136.55.6362
222137.136.55.64/26137.136.55.65 to 137.136.55.126137.136.55.12762
223137.136.55.128/26137.136.55.129 to 137.136.55.190137.136.55.19162
224137.136.55.192/26137.136.55.193 to 137.136.55.254137.136.55.25562
225137.136.56.0/26137.136.56.1 to 137.136.56.62137.136.56.6362
226137.136.56.64/26137.136.56.65 to 137.136.56.126137.136.56.12762
227137.136.56.128/26137.136.56.129 to 137.136.56.190137.136.56.19162
228137.136.56.192/26137.136.56.193 to 137.136.56.254137.136.56.25562
229137.136.57.0/26137.136.57.1 to 137.136.57.62137.136.57.6362
230137.136.57.64/26137.136.57.65 to 137.136.57.126137.136.57.12762
231137.136.57.128/26137.136.57.129 to 137.136.57.190137.136.57.19162
232137.136.57.192/26137.136.57.193 to 137.136.57.254137.136.57.25562
233137.136.58.0/26137.136.58.1 to 137.136.58.62137.136.58.6362
234137.136.58.64/26137.136.58.65 to 137.136.58.126137.136.58.12762
235137.136.58.128/26137.136.58.129 to 137.136.58.190137.136.58.19162
236137.136.58.192/26137.136.58.193 to 137.136.58.254137.136.58.25562
237137.136.59.0/26137.136.59.1 to 137.136.59.62137.136.59.6362
238137.136.59.64/26137.136.59.65 to 137.136.59.126137.136.59.12762
239137.136.59.128/26137.136.59.129 to 137.136.59.190137.136.59.19162
240137.136.59.192/26137.136.59.193 to 137.136.59.254137.136.59.25562
241137.136.60.0/26137.136.60.1 to 137.136.60.62137.136.60.6362
242137.136.60.64/26137.136.60.65 to 137.136.60.126137.136.60.12762
243137.136.60.128/26137.136.60.129 to 137.136.60.190137.136.60.19162
244137.136.60.192/26137.136.60.193 to 137.136.60.254137.136.60.25562
245137.136.61.0/26137.136.61.1 to 137.136.61.62137.136.61.6362
246137.136.61.64/26137.136.61.65 to 137.136.61.126137.136.61.12762
247137.136.61.128/26137.136.61.129 to 137.136.61.190137.136.61.19162
248137.136.61.192/26137.136.61.193 to 137.136.61.254137.136.61.25562
249137.136.62.0/26137.136.62.1 to 137.136.62.62137.136.62.6362
250137.136.62.64/26137.136.62.65 to 137.136.62.126137.136.62.12762
251137.136.62.128/26137.136.62.129 to 137.136.62.190137.136.62.19162
252137.136.62.192/26137.136.62.193 to 137.136.62.254137.136.62.25562
253137.136.63.0/26137.136.63.1 to 137.136.63.62137.136.63.6362
254137.136.63.64/26137.136.63.65 to 137.136.63.126137.136.63.12762
255137.136.63.128/26137.136.63.129 to 137.136.63.190137.136.63.19162
256137.136.63.192/26137.136.63.193 to 137.136.63.254137.136.63.25562

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.