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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.

Network142.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
142.0.0.0
Broadcast address
143.255.255.255
First usable
142.0.0.1
Last usable
143.255.255.254
Usable hosts
33,554,430 (33,554,432 less the network and broadcast addresses)
Subnet mask
254.0.0.0
Wildcard mask
1.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/7
Type
Public public
Old class
B (default /16)
As numbers
Hex 8E000000 · Integer 2382364672 to 2415919103
Reverse DNS zones
142.in-addr.arpa
143.in-addr.arpa
/7 is not on a 8-bit boundary, so it takes 2 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10001110.00000000.00000000.00000000142.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network10001110.00000000.00000000.00000000142.0.0.0
Broadcast10001111.11111111.11111111.11111111143.255.255.255
Split into smaller subnets/19
/8 (2)/9 (4)/10 (8)/11 (16)/12 (32)/13 (64)/14 (128)/15 (256)/16 (512)/17 (1,024)/18 (2,048)/19 (4,096)

142.0.0.0/7 makes 4,096 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1142.0.0.0/19142.0.0.1 to 142.0.31.254142.0.31.2558,190
2142.0.32.0/19142.0.32.1 to 142.0.63.254142.0.63.2558,190
3142.0.64.0/19142.0.64.1 to 142.0.95.254142.0.95.2558,190
4142.0.96.0/19142.0.96.1 to 142.0.127.254142.0.127.2558,190
5142.0.128.0/19142.0.128.1 to 142.0.159.254142.0.159.2558,190
6142.0.160.0/19142.0.160.1 to 142.0.191.254142.0.191.2558,190
7142.0.192.0/19142.0.192.1 to 142.0.223.254142.0.223.2558,190
8142.0.224.0/19142.0.224.1 to 142.0.255.254142.0.255.2558,190
9142.1.0.0/19142.1.0.1 to 142.1.31.254142.1.31.2558,190
10142.1.32.0/19142.1.32.1 to 142.1.63.254142.1.63.2558,190
11142.1.64.0/19142.1.64.1 to 142.1.95.254142.1.95.2558,190
12142.1.96.0/19142.1.96.1 to 142.1.127.254142.1.127.2558,190
13142.1.128.0/19142.1.128.1 to 142.1.159.254142.1.159.2558,190
14142.1.160.0/19142.1.160.1 to 142.1.191.254142.1.191.2558,190
15142.1.192.0/19142.1.192.1 to 142.1.223.254142.1.223.2558,190
16142.1.224.0/19142.1.224.1 to 142.1.255.254142.1.255.2558,190
17142.2.0.0/19142.2.0.1 to 142.2.31.254142.2.31.2558,190
18142.2.32.0/19142.2.32.1 to 142.2.63.254142.2.63.2558,190
19142.2.64.0/19142.2.64.1 to 142.2.95.254142.2.95.2558,190
20142.2.96.0/19142.2.96.1 to 142.2.127.254142.2.127.2558,190
21142.2.128.0/19142.2.128.1 to 142.2.159.254142.2.159.2558,190
22142.2.160.0/19142.2.160.1 to 142.2.191.254142.2.191.2558,190
23142.2.192.0/19142.2.192.1 to 142.2.223.254142.2.223.2558,190
24142.2.224.0/19142.2.224.1 to 142.2.255.254142.2.255.2558,190
25142.3.0.0/19142.3.0.1 to 142.3.31.254142.3.31.2558,190
26142.3.32.0/19142.3.32.1 to 142.3.63.254142.3.63.2558,190
27142.3.64.0/19142.3.64.1 to 142.3.95.254142.3.95.2558,190
28142.3.96.0/19142.3.96.1 to 142.3.127.254142.3.127.2558,190
29142.3.128.0/19142.3.128.1 to 142.3.159.254142.3.159.2558,190
30142.3.160.0/19142.3.160.1 to 142.3.191.254142.3.191.2558,190
31142.3.192.0/19142.3.192.1 to 142.3.223.254142.3.223.2558,190
32142.3.224.0/19142.3.224.1 to 142.3.255.254142.3.255.2558,190
33142.4.0.0/19142.4.0.1 to 142.4.31.254142.4.31.2558,190
34142.4.32.0/19142.4.32.1 to 142.4.63.254142.4.63.2558,190
35142.4.64.0/19142.4.64.1 to 142.4.95.254142.4.95.2558,190
36142.4.96.0/19142.4.96.1 to 142.4.127.254142.4.127.2558,190
37142.4.128.0/19142.4.128.1 to 142.4.159.254142.4.159.2558,190
38142.4.160.0/19142.4.160.1 to 142.4.191.254142.4.191.2558,190
39142.4.192.0/19142.4.192.1 to 142.4.223.254142.4.223.2558,190
40142.4.224.0/19142.4.224.1 to 142.4.255.254142.4.255.2558,190
41142.5.0.0/19142.5.0.1 to 142.5.31.254142.5.31.2558,190
42142.5.32.0/19142.5.32.1 to 142.5.63.254142.5.63.2558,190
43142.5.64.0/19142.5.64.1 to 142.5.95.254142.5.95.2558,190
44142.5.96.0/19142.5.96.1 to 142.5.127.254142.5.127.2558,190
45142.5.128.0/19142.5.128.1 to 142.5.159.254142.5.159.2558,190
46142.5.160.0/19142.5.160.1 to 142.5.191.254142.5.191.2558,190
47142.5.192.0/19142.5.192.1 to 142.5.223.254142.5.223.2558,190
48142.5.224.0/19142.5.224.1 to 142.5.255.254142.5.255.2558,190
49142.6.0.0/19142.6.0.1 to 142.6.31.254142.6.31.2558,190
50142.6.32.0/19142.6.32.1 to 142.6.63.254142.6.63.2558,190
51142.6.64.0/19142.6.64.1 to 142.6.95.254142.6.95.2558,190
52142.6.96.0/19142.6.96.1 to 142.6.127.254142.6.127.2558,190
53142.6.128.0/19142.6.128.1 to 142.6.159.254142.6.159.2558,190
54142.6.160.0/19142.6.160.1 to 142.6.191.254142.6.191.2558,190
55142.6.192.0/19142.6.192.1 to 142.6.223.254142.6.223.2558,190
56142.6.224.0/19142.6.224.1 to 142.6.255.254142.6.255.2558,190
57142.7.0.0/19142.7.0.1 to 142.7.31.254142.7.31.2558,190
58142.7.32.0/19142.7.32.1 to 142.7.63.254142.7.63.2558,190
59142.7.64.0/19142.7.64.1 to 142.7.95.254142.7.95.2558,190
60142.7.96.0/19142.7.96.1 to 142.7.127.254142.7.127.2558,190
61142.7.128.0/19142.7.128.1 to 142.7.159.254142.7.159.2558,190
62142.7.160.0/19142.7.160.1 to 142.7.191.254142.7.191.2558,190
63142.7.192.0/19142.7.192.1 to 142.7.223.254142.7.223.2558,190
64142.7.224.0/19142.7.224.1 to 142.7.255.254142.7.255.2558,190
65142.8.0.0/19142.8.0.1 to 142.8.31.254142.8.31.2558,190
66142.8.32.0/19142.8.32.1 to 142.8.63.254142.8.63.2558,190
67142.8.64.0/19142.8.64.1 to 142.8.95.254142.8.95.2558,190
68142.8.96.0/19142.8.96.1 to 142.8.127.254142.8.127.2558,190
69142.8.128.0/19142.8.128.1 to 142.8.159.254142.8.159.2558,190
70142.8.160.0/19142.8.160.1 to 142.8.191.254142.8.191.2558,190
71142.8.192.0/19142.8.192.1 to 142.8.223.254142.8.223.2558,190
72142.8.224.0/19142.8.224.1 to 142.8.255.254142.8.255.2558,190
73142.9.0.0/19142.9.0.1 to 142.9.31.254142.9.31.2558,190
74142.9.32.0/19142.9.32.1 to 142.9.63.254142.9.63.2558,190
75142.9.64.0/19142.9.64.1 to 142.9.95.254142.9.95.2558,190
76142.9.96.0/19142.9.96.1 to 142.9.127.254142.9.127.2558,190
77142.9.128.0/19142.9.128.1 to 142.9.159.254142.9.159.2558,190
78142.9.160.0/19142.9.160.1 to 142.9.191.254142.9.191.2558,190
79142.9.192.0/19142.9.192.1 to 142.9.223.254142.9.223.2558,190
80142.9.224.0/19142.9.224.1 to 142.9.255.254142.9.255.2558,190
81142.10.0.0/19142.10.0.1 to 142.10.31.254142.10.31.2558,190
82142.10.32.0/19142.10.32.1 to 142.10.63.254142.10.63.2558,190
83142.10.64.0/19142.10.64.1 to 142.10.95.254142.10.95.2558,190
84142.10.96.0/19142.10.96.1 to 142.10.127.254142.10.127.2558,190
85142.10.128.0/19142.10.128.1 to 142.10.159.254142.10.159.2558,190
86142.10.160.0/19142.10.160.1 to 142.10.191.254142.10.191.2558,190
87142.10.192.0/19142.10.192.1 to 142.10.223.254142.10.223.2558,190
88142.10.224.0/19142.10.224.1 to 142.10.255.254142.10.255.2558,190
89142.11.0.0/19142.11.0.1 to 142.11.31.254142.11.31.2558,190
90142.11.32.0/19142.11.32.1 to 142.11.63.254142.11.63.2558,190
91142.11.64.0/19142.11.64.1 to 142.11.95.254142.11.95.2558,190
92142.11.96.0/19142.11.96.1 to 142.11.127.254142.11.127.2558,190
93142.11.128.0/19142.11.128.1 to 142.11.159.254142.11.159.2558,190
94142.11.160.0/19142.11.160.1 to 142.11.191.254142.11.191.2558,190
95142.11.192.0/19142.11.192.1 to 142.11.223.254142.11.223.2558,190
96142.11.224.0/19142.11.224.1 to 142.11.255.254142.11.255.2558,190
97142.12.0.0/19142.12.0.1 to 142.12.31.254142.12.31.2558,190
98142.12.32.0/19142.12.32.1 to 142.12.63.254142.12.63.2558,190
99142.12.64.0/19142.12.64.1 to 142.12.95.254142.12.95.2558,190
100142.12.96.0/19142.12.96.1 to 142.12.127.254142.12.127.2558,190
101142.12.128.0/19142.12.128.1 to 142.12.159.254142.12.159.2558,190
102142.12.160.0/19142.12.160.1 to 142.12.191.254142.12.191.2558,190
103142.12.192.0/19142.12.192.1 to 142.12.223.254142.12.223.2558,190
104142.12.224.0/19142.12.224.1 to 142.12.255.254142.12.255.2558,190
105142.13.0.0/19142.13.0.1 to 142.13.31.254142.13.31.2558,190
106142.13.32.0/19142.13.32.1 to 142.13.63.254142.13.63.2558,190
107142.13.64.0/19142.13.64.1 to 142.13.95.254142.13.95.2558,190
108142.13.96.0/19142.13.96.1 to 142.13.127.254142.13.127.2558,190
109142.13.128.0/19142.13.128.1 to 142.13.159.254142.13.159.2558,190
110142.13.160.0/19142.13.160.1 to 142.13.191.254142.13.191.2558,190
111142.13.192.0/19142.13.192.1 to 142.13.223.254142.13.223.2558,190
112142.13.224.0/19142.13.224.1 to 142.13.255.254142.13.255.2558,190
113142.14.0.0/19142.14.0.1 to 142.14.31.254142.14.31.2558,190
114142.14.32.0/19142.14.32.1 to 142.14.63.254142.14.63.2558,190
115142.14.64.0/19142.14.64.1 to 142.14.95.254142.14.95.2558,190
116142.14.96.0/19142.14.96.1 to 142.14.127.254142.14.127.2558,190
117142.14.128.0/19142.14.128.1 to 142.14.159.254142.14.159.2558,190
118142.14.160.0/19142.14.160.1 to 142.14.191.254142.14.191.2558,190
119142.14.192.0/19142.14.192.1 to 142.14.223.254142.14.223.2558,190
120142.14.224.0/19142.14.224.1 to 142.14.255.254142.14.255.2558,190
121142.15.0.0/19142.15.0.1 to 142.15.31.254142.15.31.2558,190
122142.15.32.0/19142.15.32.1 to 142.15.63.254142.15.63.2558,190
123142.15.64.0/19142.15.64.1 to 142.15.95.254142.15.95.2558,190
124142.15.96.0/19142.15.96.1 to 142.15.127.254142.15.127.2558,190
125142.15.128.0/19142.15.128.1 to 142.15.159.254142.15.159.2558,190
126142.15.160.0/19142.15.160.1 to 142.15.191.254142.15.191.2558,190
127142.15.192.0/19142.15.192.1 to 142.15.223.254142.15.223.2558,190
128142.15.224.0/19142.15.224.1 to 142.15.255.254142.15.255.2558,190
129142.16.0.0/19142.16.0.1 to 142.16.31.254142.16.31.2558,190
130142.16.32.0/19142.16.32.1 to 142.16.63.254142.16.63.2558,190
131142.16.64.0/19142.16.64.1 to 142.16.95.254142.16.95.2558,190
132142.16.96.0/19142.16.96.1 to 142.16.127.254142.16.127.2558,190
133142.16.128.0/19142.16.128.1 to 142.16.159.254142.16.159.2558,190
134142.16.160.0/19142.16.160.1 to 142.16.191.254142.16.191.2558,190
135142.16.192.0/19142.16.192.1 to 142.16.223.254142.16.223.2558,190
136142.16.224.0/19142.16.224.1 to 142.16.255.254142.16.255.2558,190
137142.17.0.0/19142.17.0.1 to 142.17.31.254142.17.31.2558,190
138142.17.32.0/19142.17.32.1 to 142.17.63.254142.17.63.2558,190
139142.17.64.0/19142.17.64.1 to 142.17.95.254142.17.95.2558,190
140142.17.96.0/19142.17.96.1 to 142.17.127.254142.17.127.2558,190
141142.17.128.0/19142.17.128.1 to 142.17.159.254142.17.159.2558,190
142142.17.160.0/19142.17.160.1 to 142.17.191.254142.17.191.2558,190
143142.17.192.0/19142.17.192.1 to 142.17.223.254142.17.223.2558,190
144142.17.224.0/19142.17.224.1 to 142.17.255.254142.17.255.2558,190
145142.18.0.0/19142.18.0.1 to 142.18.31.254142.18.31.2558,190
146142.18.32.0/19142.18.32.1 to 142.18.63.254142.18.63.2558,190
147142.18.64.0/19142.18.64.1 to 142.18.95.254142.18.95.2558,190
148142.18.96.0/19142.18.96.1 to 142.18.127.254142.18.127.2558,190
149142.18.128.0/19142.18.128.1 to 142.18.159.254142.18.159.2558,190
150142.18.160.0/19142.18.160.1 to 142.18.191.254142.18.191.2558,190
151142.18.192.0/19142.18.192.1 to 142.18.223.254142.18.223.2558,190
152142.18.224.0/19142.18.224.1 to 142.18.255.254142.18.255.2558,190
153142.19.0.0/19142.19.0.1 to 142.19.31.254142.19.31.2558,190
154142.19.32.0/19142.19.32.1 to 142.19.63.254142.19.63.2558,190
155142.19.64.0/19142.19.64.1 to 142.19.95.254142.19.95.2558,190
156142.19.96.0/19142.19.96.1 to 142.19.127.254142.19.127.2558,190
157142.19.128.0/19142.19.128.1 to 142.19.159.254142.19.159.2558,190
158142.19.160.0/19142.19.160.1 to 142.19.191.254142.19.191.2558,190
159142.19.192.0/19142.19.192.1 to 142.19.223.254142.19.223.2558,190
160142.19.224.0/19142.19.224.1 to 142.19.255.254142.19.255.2558,190
161142.20.0.0/19142.20.0.1 to 142.20.31.254142.20.31.2558,190
162142.20.32.0/19142.20.32.1 to 142.20.63.254142.20.63.2558,190
163142.20.64.0/19142.20.64.1 to 142.20.95.254142.20.95.2558,190
164142.20.96.0/19142.20.96.1 to 142.20.127.254142.20.127.2558,190
165142.20.128.0/19142.20.128.1 to 142.20.159.254142.20.159.2558,190
166142.20.160.0/19142.20.160.1 to 142.20.191.254142.20.191.2558,190
167142.20.192.0/19142.20.192.1 to 142.20.223.254142.20.223.2558,190
168142.20.224.0/19142.20.224.1 to 142.20.255.254142.20.255.2558,190
169142.21.0.0/19142.21.0.1 to 142.21.31.254142.21.31.2558,190
170142.21.32.0/19142.21.32.1 to 142.21.63.254142.21.63.2558,190
171142.21.64.0/19142.21.64.1 to 142.21.95.254142.21.95.2558,190
172142.21.96.0/19142.21.96.1 to 142.21.127.254142.21.127.2558,190
173142.21.128.0/19142.21.128.1 to 142.21.159.254142.21.159.2558,190
174142.21.160.0/19142.21.160.1 to 142.21.191.254142.21.191.2558,190
175142.21.192.0/19142.21.192.1 to 142.21.223.254142.21.223.2558,190
176142.21.224.0/19142.21.224.1 to 142.21.255.254142.21.255.2558,190
177142.22.0.0/19142.22.0.1 to 142.22.31.254142.22.31.2558,190
178142.22.32.0/19142.22.32.1 to 142.22.63.254142.22.63.2558,190
179142.22.64.0/19142.22.64.1 to 142.22.95.254142.22.95.2558,190
180142.22.96.0/19142.22.96.1 to 142.22.127.254142.22.127.2558,190
181142.22.128.0/19142.22.128.1 to 142.22.159.254142.22.159.2558,190
182142.22.160.0/19142.22.160.1 to 142.22.191.254142.22.191.2558,190
183142.22.192.0/19142.22.192.1 to 142.22.223.254142.22.223.2558,190
184142.22.224.0/19142.22.224.1 to 142.22.255.254142.22.255.2558,190
185142.23.0.0/19142.23.0.1 to 142.23.31.254142.23.31.2558,190
186142.23.32.0/19142.23.32.1 to 142.23.63.254142.23.63.2558,190
187142.23.64.0/19142.23.64.1 to 142.23.95.254142.23.95.2558,190
188142.23.96.0/19142.23.96.1 to 142.23.127.254142.23.127.2558,190
189142.23.128.0/19142.23.128.1 to 142.23.159.254142.23.159.2558,190
190142.23.160.0/19142.23.160.1 to 142.23.191.254142.23.191.2558,190
191142.23.192.0/19142.23.192.1 to 142.23.223.254142.23.223.2558,190
192142.23.224.0/19142.23.224.1 to 142.23.255.254142.23.255.2558,190
193142.24.0.0/19142.24.0.1 to 142.24.31.254142.24.31.2558,190
194142.24.32.0/19142.24.32.1 to 142.24.63.254142.24.63.2558,190
195142.24.64.0/19142.24.64.1 to 142.24.95.254142.24.95.2558,190
196142.24.96.0/19142.24.96.1 to 142.24.127.254142.24.127.2558,190
197142.24.128.0/19142.24.128.1 to 142.24.159.254142.24.159.2558,190
198142.24.160.0/19142.24.160.1 to 142.24.191.254142.24.191.2558,190
199142.24.192.0/19142.24.192.1 to 142.24.223.254142.24.223.2558,190
200142.24.224.0/19142.24.224.1 to 142.24.255.254142.24.255.2558,190
201142.25.0.0/19142.25.0.1 to 142.25.31.254142.25.31.2558,190
202142.25.32.0/19142.25.32.1 to 142.25.63.254142.25.63.2558,190
203142.25.64.0/19142.25.64.1 to 142.25.95.254142.25.95.2558,190
204142.25.96.0/19142.25.96.1 to 142.25.127.254142.25.127.2558,190
205142.25.128.0/19142.25.128.1 to 142.25.159.254142.25.159.2558,190
206142.25.160.0/19142.25.160.1 to 142.25.191.254142.25.191.2558,190
207142.25.192.0/19142.25.192.1 to 142.25.223.254142.25.223.2558,190
208142.25.224.0/19142.25.224.1 to 142.25.255.254142.25.255.2558,190
209142.26.0.0/19142.26.0.1 to 142.26.31.254142.26.31.2558,190
210142.26.32.0/19142.26.32.1 to 142.26.63.254142.26.63.2558,190
211142.26.64.0/19142.26.64.1 to 142.26.95.254142.26.95.2558,190
212142.26.96.0/19142.26.96.1 to 142.26.127.254142.26.127.2558,190
213142.26.128.0/19142.26.128.1 to 142.26.159.254142.26.159.2558,190
214142.26.160.0/19142.26.160.1 to 142.26.191.254142.26.191.2558,190
215142.26.192.0/19142.26.192.1 to 142.26.223.254142.26.223.2558,190
216142.26.224.0/19142.26.224.1 to 142.26.255.254142.26.255.2558,190
217142.27.0.0/19142.27.0.1 to 142.27.31.254142.27.31.2558,190
218142.27.32.0/19142.27.32.1 to 142.27.63.254142.27.63.2558,190
219142.27.64.0/19142.27.64.1 to 142.27.95.254142.27.95.2558,190
220142.27.96.0/19142.27.96.1 to 142.27.127.254142.27.127.2558,190
221142.27.128.0/19142.27.128.1 to 142.27.159.254142.27.159.2558,190
222142.27.160.0/19142.27.160.1 to 142.27.191.254142.27.191.2558,190
223142.27.192.0/19142.27.192.1 to 142.27.223.254142.27.223.2558,190
224142.27.224.0/19142.27.224.1 to 142.27.255.254142.27.255.2558,190
225142.28.0.0/19142.28.0.1 to 142.28.31.254142.28.31.2558,190
226142.28.32.0/19142.28.32.1 to 142.28.63.254142.28.63.2558,190
227142.28.64.0/19142.28.64.1 to 142.28.95.254142.28.95.2558,190
228142.28.96.0/19142.28.96.1 to 142.28.127.254142.28.127.2558,190
229142.28.128.0/19142.28.128.1 to 142.28.159.254142.28.159.2558,190
230142.28.160.0/19142.28.160.1 to 142.28.191.254142.28.191.2558,190
231142.28.192.0/19142.28.192.1 to 142.28.223.254142.28.223.2558,190
232142.28.224.0/19142.28.224.1 to 142.28.255.254142.28.255.2558,190
233142.29.0.0/19142.29.0.1 to 142.29.31.254142.29.31.2558,190
234142.29.32.0/19142.29.32.1 to 142.29.63.254142.29.63.2558,190
235142.29.64.0/19142.29.64.1 to 142.29.95.254142.29.95.2558,190
236142.29.96.0/19142.29.96.1 to 142.29.127.254142.29.127.2558,190
237142.29.128.0/19142.29.128.1 to 142.29.159.254142.29.159.2558,190
238142.29.160.0/19142.29.160.1 to 142.29.191.254142.29.191.2558,190
239142.29.192.0/19142.29.192.1 to 142.29.223.254142.29.223.2558,190
240142.29.224.0/19142.29.224.1 to 142.29.255.254142.29.255.2558,190
241142.30.0.0/19142.30.0.1 to 142.30.31.254142.30.31.2558,190
242142.30.32.0/19142.30.32.1 to 142.30.63.254142.30.63.2558,190
243142.30.64.0/19142.30.64.1 to 142.30.95.254142.30.95.2558,190
244142.30.96.0/19142.30.96.1 to 142.30.127.254142.30.127.2558,190
245142.30.128.0/19142.30.128.1 to 142.30.159.254142.30.159.2558,190
246142.30.160.0/19142.30.160.1 to 142.30.191.254142.30.191.2558,190
247142.30.192.0/19142.30.192.1 to 142.30.223.254142.30.223.2558,190
248142.30.224.0/19142.30.224.1 to 142.30.255.254142.30.255.2558,190
249142.31.0.0/19142.31.0.1 to 142.31.31.254142.31.31.2558,190
250142.31.32.0/19142.31.32.1 to 142.31.63.254142.31.63.2558,190
251142.31.64.0/19142.31.64.1 to 142.31.95.254142.31.95.2558,190
252142.31.96.0/19142.31.96.1 to 142.31.127.254142.31.127.2558,190
253142.31.128.0/19142.31.128.1 to 142.31.159.254142.31.159.2558,190
254142.31.160.0/19142.31.160.1 to 142.31.191.254142.31.191.2558,190
255142.31.192.0/19142.31.192.1 to 142.31.223.254142.31.223.2558,190
256142.31.224.0/19142.31.224.1 to 142.31.255.254142.31.255.2558,190

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.