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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.

Network142.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
142.0.0.0
Broadcast address
142.255.255.255
First usable
142.0.0.1
Last usable
142.255.255.254
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
B (default /16)
As numbers
Hex 8E000000 · Integer 2382364672 to 2399141887
Reverse DNS zone
142.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10001110..00000000.00000000.00000000142.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network10001110..00000000.00000000.00000000142.0.0.0
Broadcast10001110..11111111.11111111.11111111142.255.255.255
Split into smaller subnets/20
/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)

142.0.0.0/8 makes 4,096 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1142.0.0.0/20142.0.0.1 to 142.0.15.254142.0.15.2554,094
2142.0.16.0/20142.0.16.1 to 142.0.31.254142.0.31.2554,094
3142.0.32.0/20142.0.32.1 to 142.0.47.254142.0.47.2554,094
4142.0.48.0/20142.0.48.1 to 142.0.63.254142.0.63.2554,094
5142.0.64.0/20142.0.64.1 to 142.0.79.254142.0.79.2554,094
6142.0.80.0/20142.0.80.1 to 142.0.95.254142.0.95.2554,094
7142.0.96.0/20142.0.96.1 to 142.0.111.254142.0.111.2554,094
8142.0.112.0/20142.0.112.1 to 142.0.127.254142.0.127.2554,094
9142.0.128.0/20142.0.128.1 to 142.0.143.254142.0.143.2554,094
10142.0.144.0/20142.0.144.1 to 142.0.159.254142.0.159.2554,094
11142.0.160.0/20142.0.160.1 to 142.0.175.254142.0.175.2554,094
12142.0.176.0/20142.0.176.1 to 142.0.191.254142.0.191.2554,094
13142.0.192.0/20142.0.192.1 to 142.0.207.254142.0.207.2554,094
14142.0.208.0/20142.0.208.1 to 142.0.223.254142.0.223.2554,094
15142.0.224.0/20142.0.224.1 to 142.0.239.254142.0.239.2554,094
16142.0.240.0/20142.0.240.1 to 142.0.255.254142.0.255.2554,094
17142.1.0.0/20142.1.0.1 to 142.1.15.254142.1.15.2554,094
18142.1.16.0/20142.1.16.1 to 142.1.31.254142.1.31.2554,094
19142.1.32.0/20142.1.32.1 to 142.1.47.254142.1.47.2554,094
20142.1.48.0/20142.1.48.1 to 142.1.63.254142.1.63.2554,094
21142.1.64.0/20142.1.64.1 to 142.1.79.254142.1.79.2554,094
22142.1.80.0/20142.1.80.1 to 142.1.95.254142.1.95.2554,094
23142.1.96.0/20142.1.96.1 to 142.1.111.254142.1.111.2554,094
24142.1.112.0/20142.1.112.1 to 142.1.127.254142.1.127.2554,094
25142.1.128.0/20142.1.128.1 to 142.1.143.254142.1.143.2554,094
26142.1.144.0/20142.1.144.1 to 142.1.159.254142.1.159.2554,094
27142.1.160.0/20142.1.160.1 to 142.1.175.254142.1.175.2554,094
28142.1.176.0/20142.1.176.1 to 142.1.191.254142.1.191.2554,094
29142.1.192.0/20142.1.192.1 to 142.1.207.254142.1.207.2554,094
30142.1.208.0/20142.1.208.1 to 142.1.223.254142.1.223.2554,094
31142.1.224.0/20142.1.224.1 to 142.1.239.254142.1.239.2554,094
32142.1.240.0/20142.1.240.1 to 142.1.255.254142.1.255.2554,094
33142.2.0.0/20142.2.0.1 to 142.2.15.254142.2.15.2554,094
34142.2.16.0/20142.2.16.1 to 142.2.31.254142.2.31.2554,094
35142.2.32.0/20142.2.32.1 to 142.2.47.254142.2.47.2554,094
36142.2.48.0/20142.2.48.1 to 142.2.63.254142.2.63.2554,094
37142.2.64.0/20142.2.64.1 to 142.2.79.254142.2.79.2554,094
38142.2.80.0/20142.2.80.1 to 142.2.95.254142.2.95.2554,094
39142.2.96.0/20142.2.96.1 to 142.2.111.254142.2.111.2554,094
40142.2.112.0/20142.2.112.1 to 142.2.127.254142.2.127.2554,094
41142.2.128.0/20142.2.128.1 to 142.2.143.254142.2.143.2554,094
42142.2.144.0/20142.2.144.1 to 142.2.159.254142.2.159.2554,094
43142.2.160.0/20142.2.160.1 to 142.2.175.254142.2.175.2554,094
44142.2.176.0/20142.2.176.1 to 142.2.191.254142.2.191.2554,094
45142.2.192.0/20142.2.192.1 to 142.2.207.254142.2.207.2554,094
46142.2.208.0/20142.2.208.1 to 142.2.223.254142.2.223.2554,094
47142.2.224.0/20142.2.224.1 to 142.2.239.254142.2.239.2554,094
48142.2.240.0/20142.2.240.1 to 142.2.255.254142.2.255.2554,094
49142.3.0.0/20142.3.0.1 to 142.3.15.254142.3.15.2554,094
50142.3.16.0/20142.3.16.1 to 142.3.31.254142.3.31.2554,094
51142.3.32.0/20142.3.32.1 to 142.3.47.254142.3.47.2554,094
52142.3.48.0/20142.3.48.1 to 142.3.63.254142.3.63.2554,094
53142.3.64.0/20142.3.64.1 to 142.3.79.254142.3.79.2554,094
54142.3.80.0/20142.3.80.1 to 142.3.95.254142.3.95.2554,094
55142.3.96.0/20142.3.96.1 to 142.3.111.254142.3.111.2554,094
56142.3.112.0/20142.3.112.1 to 142.3.127.254142.3.127.2554,094
57142.3.128.0/20142.3.128.1 to 142.3.143.254142.3.143.2554,094
58142.3.144.0/20142.3.144.1 to 142.3.159.254142.3.159.2554,094
59142.3.160.0/20142.3.160.1 to 142.3.175.254142.3.175.2554,094
60142.3.176.0/20142.3.176.1 to 142.3.191.254142.3.191.2554,094
61142.3.192.0/20142.3.192.1 to 142.3.207.254142.3.207.2554,094
62142.3.208.0/20142.3.208.1 to 142.3.223.254142.3.223.2554,094
63142.3.224.0/20142.3.224.1 to 142.3.239.254142.3.239.2554,094
64142.3.240.0/20142.3.240.1 to 142.3.255.254142.3.255.2554,094
65142.4.0.0/20142.4.0.1 to 142.4.15.254142.4.15.2554,094
66142.4.16.0/20142.4.16.1 to 142.4.31.254142.4.31.2554,094
67142.4.32.0/20142.4.32.1 to 142.4.47.254142.4.47.2554,094
68142.4.48.0/20142.4.48.1 to 142.4.63.254142.4.63.2554,094
69142.4.64.0/20142.4.64.1 to 142.4.79.254142.4.79.2554,094
70142.4.80.0/20142.4.80.1 to 142.4.95.254142.4.95.2554,094
71142.4.96.0/20142.4.96.1 to 142.4.111.254142.4.111.2554,094
72142.4.112.0/20142.4.112.1 to 142.4.127.254142.4.127.2554,094
73142.4.128.0/20142.4.128.1 to 142.4.143.254142.4.143.2554,094
74142.4.144.0/20142.4.144.1 to 142.4.159.254142.4.159.2554,094
75142.4.160.0/20142.4.160.1 to 142.4.175.254142.4.175.2554,094
76142.4.176.0/20142.4.176.1 to 142.4.191.254142.4.191.2554,094
77142.4.192.0/20142.4.192.1 to 142.4.207.254142.4.207.2554,094
78142.4.208.0/20142.4.208.1 to 142.4.223.254142.4.223.2554,094
79142.4.224.0/20142.4.224.1 to 142.4.239.254142.4.239.2554,094
80142.4.240.0/20142.4.240.1 to 142.4.255.254142.4.255.2554,094
81142.5.0.0/20142.5.0.1 to 142.5.15.254142.5.15.2554,094
82142.5.16.0/20142.5.16.1 to 142.5.31.254142.5.31.2554,094
83142.5.32.0/20142.5.32.1 to 142.5.47.254142.5.47.2554,094
84142.5.48.0/20142.5.48.1 to 142.5.63.254142.5.63.2554,094
85142.5.64.0/20142.5.64.1 to 142.5.79.254142.5.79.2554,094
86142.5.80.0/20142.5.80.1 to 142.5.95.254142.5.95.2554,094
87142.5.96.0/20142.5.96.1 to 142.5.111.254142.5.111.2554,094
88142.5.112.0/20142.5.112.1 to 142.5.127.254142.5.127.2554,094
89142.5.128.0/20142.5.128.1 to 142.5.143.254142.5.143.2554,094
90142.5.144.0/20142.5.144.1 to 142.5.159.254142.5.159.2554,094
91142.5.160.0/20142.5.160.1 to 142.5.175.254142.5.175.2554,094
92142.5.176.0/20142.5.176.1 to 142.5.191.254142.5.191.2554,094
93142.5.192.0/20142.5.192.1 to 142.5.207.254142.5.207.2554,094
94142.5.208.0/20142.5.208.1 to 142.5.223.254142.5.223.2554,094
95142.5.224.0/20142.5.224.1 to 142.5.239.254142.5.239.2554,094
96142.5.240.0/20142.5.240.1 to 142.5.255.254142.5.255.2554,094
97142.6.0.0/20142.6.0.1 to 142.6.15.254142.6.15.2554,094
98142.6.16.0/20142.6.16.1 to 142.6.31.254142.6.31.2554,094
99142.6.32.0/20142.6.32.1 to 142.6.47.254142.6.47.2554,094
100142.6.48.0/20142.6.48.1 to 142.6.63.254142.6.63.2554,094
101142.6.64.0/20142.6.64.1 to 142.6.79.254142.6.79.2554,094
102142.6.80.0/20142.6.80.1 to 142.6.95.254142.6.95.2554,094
103142.6.96.0/20142.6.96.1 to 142.6.111.254142.6.111.2554,094
104142.6.112.0/20142.6.112.1 to 142.6.127.254142.6.127.2554,094
105142.6.128.0/20142.6.128.1 to 142.6.143.254142.6.143.2554,094
106142.6.144.0/20142.6.144.1 to 142.6.159.254142.6.159.2554,094
107142.6.160.0/20142.6.160.1 to 142.6.175.254142.6.175.2554,094
108142.6.176.0/20142.6.176.1 to 142.6.191.254142.6.191.2554,094
109142.6.192.0/20142.6.192.1 to 142.6.207.254142.6.207.2554,094
110142.6.208.0/20142.6.208.1 to 142.6.223.254142.6.223.2554,094
111142.6.224.0/20142.6.224.1 to 142.6.239.254142.6.239.2554,094
112142.6.240.0/20142.6.240.1 to 142.6.255.254142.6.255.2554,094
113142.7.0.0/20142.7.0.1 to 142.7.15.254142.7.15.2554,094
114142.7.16.0/20142.7.16.1 to 142.7.31.254142.7.31.2554,094
115142.7.32.0/20142.7.32.1 to 142.7.47.254142.7.47.2554,094
116142.7.48.0/20142.7.48.1 to 142.7.63.254142.7.63.2554,094
117142.7.64.0/20142.7.64.1 to 142.7.79.254142.7.79.2554,094
118142.7.80.0/20142.7.80.1 to 142.7.95.254142.7.95.2554,094
119142.7.96.0/20142.7.96.1 to 142.7.111.254142.7.111.2554,094
120142.7.112.0/20142.7.112.1 to 142.7.127.254142.7.127.2554,094
121142.7.128.0/20142.7.128.1 to 142.7.143.254142.7.143.2554,094
122142.7.144.0/20142.7.144.1 to 142.7.159.254142.7.159.2554,094
123142.7.160.0/20142.7.160.1 to 142.7.175.254142.7.175.2554,094
124142.7.176.0/20142.7.176.1 to 142.7.191.254142.7.191.2554,094
125142.7.192.0/20142.7.192.1 to 142.7.207.254142.7.207.2554,094
126142.7.208.0/20142.7.208.1 to 142.7.223.254142.7.223.2554,094
127142.7.224.0/20142.7.224.1 to 142.7.239.254142.7.239.2554,094
128142.7.240.0/20142.7.240.1 to 142.7.255.254142.7.255.2554,094
129142.8.0.0/20142.8.0.1 to 142.8.15.254142.8.15.2554,094
130142.8.16.0/20142.8.16.1 to 142.8.31.254142.8.31.2554,094
131142.8.32.0/20142.8.32.1 to 142.8.47.254142.8.47.2554,094
132142.8.48.0/20142.8.48.1 to 142.8.63.254142.8.63.2554,094
133142.8.64.0/20142.8.64.1 to 142.8.79.254142.8.79.2554,094
134142.8.80.0/20142.8.80.1 to 142.8.95.254142.8.95.2554,094
135142.8.96.0/20142.8.96.1 to 142.8.111.254142.8.111.2554,094
136142.8.112.0/20142.8.112.1 to 142.8.127.254142.8.127.2554,094
137142.8.128.0/20142.8.128.1 to 142.8.143.254142.8.143.2554,094
138142.8.144.0/20142.8.144.1 to 142.8.159.254142.8.159.2554,094
139142.8.160.0/20142.8.160.1 to 142.8.175.254142.8.175.2554,094
140142.8.176.0/20142.8.176.1 to 142.8.191.254142.8.191.2554,094
141142.8.192.0/20142.8.192.1 to 142.8.207.254142.8.207.2554,094
142142.8.208.0/20142.8.208.1 to 142.8.223.254142.8.223.2554,094
143142.8.224.0/20142.8.224.1 to 142.8.239.254142.8.239.2554,094
144142.8.240.0/20142.8.240.1 to 142.8.255.254142.8.255.2554,094
145142.9.0.0/20142.9.0.1 to 142.9.15.254142.9.15.2554,094
146142.9.16.0/20142.9.16.1 to 142.9.31.254142.9.31.2554,094
147142.9.32.0/20142.9.32.1 to 142.9.47.254142.9.47.2554,094
148142.9.48.0/20142.9.48.1 to 142.9.63.254142.9.63.2554,094
149142.9.64.0/20142.9.64.1 to 142.9.79.254142.9.79.2554,094
150142.9.80.0/20142.9.80.1 to 142.9.95.254142.9.95.2554,094
151142.9.96.0/20142.9.96.1 to 142.9.111.254142.9.111.2554,094
152142.9.112.0/20142.9.112.1 to 142.9.127.254142.9.127.2554,094
153142.9.128.0/20142.9.128.1 to 142.9.143.254142.9.143.2554,094
154142.9.144.0/20142.9.144.1 to 142.9.159.254142.9.159.2554,094
155142.9.160.0/20142.9.160.1 to 142.9.175.254142.9.175.2554,094
156142.9.176.0/20142.9.176.1 to 142.9.191.254142.9.191.2554,094
157142.9.192.0/20142.9.192.1 to 142.9.207.254142.9.207.2554,094
158142.9.208.0/20142.9.208.1 to 142.9.223.254142.9.223.2554,094
159142.9.224.0/20142.9.224.1 to 142.9.239.254142.9.239.2554,094
160142.9.240.0/20142.9.240.1 to 142.9.255.254142.9.255.2554,094
161142.10.0.0/20142.10.0.1 to 142.10.15.254142.10.15.2554,094
162142.10.16.0/20142.10.16.1 to 142.10.31.254142.10.31.2554,094
163142.10.32.0/20142.10.32.1 to 142.10.47.254142.10.47.2554,094
164142.10.48.0/20142.10.48.1 to 142.10.63.254142.10.63.2554,094
165142.10.64.0/20142.10.64.1 to 142.10.79.254142.10.79.2554,094
166142.10.80.0/20142.10.80.1 to 142.10.95.254142.10.95.2554,094
167142.10.96.0/20142.10.96.1 to 142.10.111.254142.10.111.2554,094
168142.10.112.0/20142.10.112.1 to 142.10.127.254142.10.127.2554,094
169142.10.128.0/20142.10.128.1 to 142.10.143.254142.10.143.2554,094
170142.10.144.0/20142.10.144.1 to 142.10.159.254142.10.159.2554,094
171142.10.160.0/20142.10.160.1 to 142.10.175.254142.10.175.2554,094
172142.10.176.0/20142.10.176.1 to 142.10.191.254142.10.191.2554,094
173142.10.192.0/20142.10.192.1 to 142.10.207.254142.10.207.2554,094
174142.10.208.0/20142.10.208.1 to 142.10.223.254142.10.223.2554,094
175142.10.224.0/20142.10.224.1 to 142.10.239.254142.10.239.2554,094
176142.10.240.0/20142.10.240.1 to 142.10.255.254142.10.255.2554,094
177142.11.0.0/20142.11.0.1 to 142.11.15.254142.11.15.2554,094
178142.11.16.0/20142.11.16.1 to 142.11.31.254142.11.31.2554,094
179142.11.32.0/20142.11.32.1 to 142.11.47.254142.11.47.2554,094
180142.11.48.0/20142.11.48.1 to 142.11.63.254142.11.63.2554,094
181142.11.64.0/20142.11.64.1 to 142.11.79.254142.11.79.2554,094
182142.11.80.0/20142.11.80.1 to 142.11.95.254142.11.95.2554,094
183142.11.96.0/20142.11.96.1 to 142.11.111.254142.11.111.2554,094
184142.11.112.0/20142.11.112.1 to 142.11.127.254142.11.127.2554,094
185142.11.128.0/20142.11.128.1 to 142.11.143.254142.11.143.2554,094
186142.11.144.0/20142.11.144.1 to 142.11.159.254142.11.159.2554,094
187142.11.160.0/20142.11.160.1 to 142.11.175.254142.11.175.2554,094
188142.11.176.0/20142.11.176.1 to 142.11.191.254142.11.191.2554,094
189142.11.192.0/20142.11.192.1 to 142.11.207.254142.11.207.2554,094
190142.11.208.0/20142.11.208.1 to 142.11.223.254142.11.223.2554,094
191142.11.224.0/20142.11.224.1 to 142.11.239.254142.11.239.2554,094
192142.11.240.0/20142.11.240.1 to 142.11.255.254142.11.255.2554,094
193142.12.0.0/20142.12.0.1 to 142.12.15.254142.12.15.2554,094
194142.12.16.0/20142.12.16.1 to 142.12.31.254142.12.31.2554,094
195142.12.32.0/20142.12.32.1 to 142.12.47.254142.12.47.2554,094
196142.12.48.0/20142.12.48.1 to 142.12.63.254142.12.63.2554,094
197142.12.64.0/20142.12.64.1 to 142.12.79.254142.12.79.2554,094
198142.12.80.0/20142.12.80.1 to 142.12.95.254142.12.95.2554,094
199142.12.96.0/20142.12.96.1 to 142.12.111.254142.12.111.2554,094
200142.12.112.0/20142.12.112.1 to 142.12.127.254142.12.127.2554,094
201142.12.128.0/20142.12.128.1 to 142.12.143.254142.12.143.2554,094
202142.12.144.0/20142.12.144.1 to 142.12.159.254142.12.159.2554,094
203142.12.160.0/20142.12.160.1 to 142.12.175.254142.12.175.2554,094
204142.12.176.0/20142.12.176.1 to 142.12.191.254142.12.191.2554,094
205142.12.192.0/20142.12.192.1 to 142.12.207.254142.12.207.2554,094
206142.12.208.0/20142.12.208.1 to 142.12.223.254142.12.223.2554,094
207142.12.224.0/20142.12.224.1 to 142.12.239.254142.12.239.2554,094
208142.12.240.0/20142.12.240.1 to 142.12.255.254142.12.255.2554,094
209142.13.0.0/20142.13.0.1 to 142.13.15.254142.13.15.2554,094
210142.13.16.0/20142.13.16.1 to 142.13.31.254142.13.31.2554,094
211142.13.32.0/20142.13.32.1 to 142.13.47.254142.13.47.2554,094
212142.13.48.0/20142.13.48.1 to 142.13.63.254142.13.63.2554,094
213142.13.64.0/20142.13.64.1 to 142.13.79.254142.13.79.2554,094
214142.13.80.0/20142.13.80.1 to 142.13.95.254142.13.95.2554,094
215142.13.96.0/20142.13.96.1 to 142.13.111.254142.13.111.2554,094
216142.13.112.0/20142.13.112.1 to 142.13.127.254142.13.127.2554,094
217142.13.128.0/20142.13.128.1 to 142.13.143.254142.13.143.2554,094
218142.13.144.0/20142.13.144.1 to 142.13.159.254142.13.159.2554,094
219142.13.160.0/20142.13.160.1 to 142.13.175.254142.13.175.2554,094
220142.13.176.0/20142.13.176.1 to 142.13.191.254142.13.191.2554,094
221142.13.192.0/20142.13.192.1 to 142.13.207.254142.13.207.2554,094
222142.13.208.0/20142.13.208.1 to 142.13.223.254142.13.223.2554,094
223142.13.224.0/20142.13.224.1 to 142.13.239.254142.13.239.2554,094
224142.13.240.0/20142.13.240.1 to 142.13.255.254142.13.255.2554,094
225142.14.0.0/20142.14.0.1 to 142.14.15.254142.14.15.2554,094
226142.14.16.0/20142.14.16.1 to 142.14.31.254142.14.31.2554,094
227142.14.32.0/20142.14.32.1 to 142.14.47.254142.14.47.2554,094
228142.14.48.0/20142.14.48.1 to 142.14.63.254142.14.63.2554,094
229142.14.64.0/20142.14.64.1 to 142.14.79.254142.14.79.2554,094
230142.14.80.0/20142.14.80.1 to 142.14.95.254142.14.95.2554,094
231142.14.96.0/20142.14.96.1 to 142.14.111.254142.14.111.2554,094
232142.14.112.0/20142.14.112.1 to 142.14.127.254142.14.127.2554,094
233142.14.128.0/20142.14.128.1 to 142.14.143.254142.14.143.2554,094
234142.14.144.0/20142.14.144.1 to 142.14.159.254142.14.159.2554,094
235142.14.160.0/20142.14.160.1 to 142.14.175.254142.14.175.2554,094
236142.14.176.0/20142.14.176.1 to 142.14.191.254142.14.191.2554,094
237142.14.192.0/20142.14.192.1 to 142.14.207.254142.14.207.2554,094
238142.14.208.0/20142.14.208.1 to 142.14.223.254142.14.223.2554,094
239142.14.224.0/20142.14.224.1 to 142.14.239.254142.14.239.2554,094
240142.14.240.0/20142.14.240.1 to 142.14.255.254142.14.255.2554,094
241142.15.0.0/20142.15.0.1 to 142.15.15.254142.15.15.2554,094
242142.15.16.0/20142.15.16.1 to 142.15.31.254142.15.31.2554,094
243142.15.32.0/20142.15.32.1 to 142.15.47.254142.15.47.2554,094
244142.15.48.0/20142.15.48.1 to 142.15.63.254142.15.63.2554,094
245142.15.64.0/20142.15.64.1 to 142.15.79.254142.15.79.2554,094
246142.15.80.0/20142.15.80.1 to 142.15.95.254142.15.95.2554,094
247142.15.96.0/20142.15.96.1 to 142.15.111.254142.15.111.2554,094
248142.15.112.0/20142.15.112.1 to 142.15.127.254142.15.127.2554,094
249142.15.128.0/20142.15.128.1 to 142.15.143.254142.15.143.2554,094
250142.15.144.0/20142.15.144.1 to 142.15.159.254142.15.159.2554,094
251142.15.160.0/20142.15.160.1 to 142.15.175.254142.15.175.2554,094
252142.15.176.0/20142.15.176.1 to 142.15.191.254142.15.191.2554,094
253142.15.192.0/20142.15.192.1 to 142.15.207.254142.15.207.2554,094
254142.15.208.0/20142.15.208.1 to 142.15.223.254142.15.223.2554,094
255142.15.224.0/20142.15.224.1 to 142.15.239.254142.15.239.2554,094
256142.15.240.0/20142.15.240.1 to 142.15.255.254142.15.255.2554,094

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.