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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.

Network140.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
140.0.0.0
Broadcast address
140.255.255.255
First usable
140.0.0.1
Last usable
140.255.255.254
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 8C000000 · Integer 2348810240 to 2365587455
Reverse DNS zone
140.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10001100..00000000.00000000.00000000140.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network10001100..00000000.00000000.00000000140.0.0.0
Broadcast10001100..11111111.11111111.11111111140.255.255.255
Split into smaller subnets/19
/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)

140.0.0.0/8 makes 2,048 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1140.0.0.0/19140.0.0.1 to 140.0.31.254140.0.31.2558,190
2140.0.32.0/19140.0.32.1 to 140.0.63.254140.0.63.2558,190
3140.0.64.0/19140.0.64.1 to 140.0.95.254140.0.95.2558,190
4140.0.96.0/19140.0.96.1 to 140.0.127.254140.0.127.2558,190
5140.0.128.0/19140.0.128.1 to 140.0.159.254140.0.159.2558,190
6140.0.160.0/19140.0.160.1 to 140.0.191.254140.0.191.2558,190
7140.0.192.0/19140.0.192.1 to 140.0.223.254140.0.223.2558,190
8140.0.224.0/19140.0.224.1 to 140.0.255.254140.0.255.2558,190
9140.1.0.0/19140.1.0.1 to 140.1.31.254140.1.31.2558,190
10140.1.32.0/19140.1.32.1 to 140.1.63.254140.1.63.2558,190
11140.1.64.0/19140.1.64.1 to 140.1.95.254140.1.95.2558,190
12140.1.96.0/19140.1.96.1 to 140.1.127.254140.1.127.2558,190
13140.1.128.0/19140.1.128.1 to 140.1.159.254140.1.159.2558,190
14140.1.160.0/19140.1.160.1 to 140.1.191.254140.1.191.2558,190
15140.1.192.0/19140.1.192.1 to 140.1.223.254140.1.223.2558,190
16140.1.224.0/19140.1.224.1 to 140.1.255.254140.1.255.2558,190
17140.2.0.0/19140.2.0.1 to 140.2.31.254140.2.31.2558,190
18140.2.32.0/19140.2.32.1 to 140.2.63.254140.2.63.2558,190
19140.2.64.0/19140.2.64.1 to 140.2.95.254140.2.95.2558,190
20140.2.96.0/19140.2.96.1 to 140.2.127.254140.2.127.2558,190
21140.2.128.0/19140.2.128.1 to 140.2.159.254140.2.159.2558,190
22140.2.160.0/19140.2.160.1 to 140.2.191.254140.2.191.2558,190
23140.2.192.0/19140.2.192.1 to 140.2.223.254140.2.223.2558,190
24140.2.224.0/19140.2.224.1 to 140.2.255.254140.2.255.2558,190
25140.3.0.0/19140.3.0.1 to 140.3.31.254140.3.31.2558,190
26140.3.32.0/19140.3.32.1 to 140.3.63.254140.3.63.2558,190
27140.3.64.0/19140.3.64.1 to 140.3.95.254140.3.95.2558,190
28140.3.96.0/19140.3.96.1 to 140.3.127.254140.3.127.2558,190
29140.3.128.0/19140.3.128.1 to 140.3.159.254140.3.159.2558,190
30140.3.160.0/19140.3.160.1 to 140.3.191.254140.3.191.2558,190
31140.3.192.0/19140.3.192.1 to 140.3.223.254140.3.223.2558,190
32140.3.224.0/19140.3.224.1 to 140.3.255.254140.3.255.2558,190
33140.4.0.0/19140.4.0.1 to 140.4.31.254140.4.31.2558,190
34140.4.32.0/19140.4.32.1 to 140.4.63.254140.4.63.2558,190
35140.4.64.0/19140.4.64.1 to 140.4.95.254140.4.95.2558,190
36140.4.96.0/19140.4.96.1 to 140.4.127.254140.4.127.2558,190
37140.4.128.0/19140.4.128.1 to 140.4.159.254140.4.159.2558,190
38140.4.160.0/19140.4.160.1 to 140.4.191.254140.4.191.2558,190
39140.4.192.0/19140.4.192.1 to 140.4.223.254140.4.223.2558,190
40140.4.224.0/19140.4.224.1 to 140.4.255.254140.4.255.2558,190
41140.5.0.0/19140.5.0.1 to 140.5.31.254140.5.31.2558,190
42140.5.32.0/19140.5.32.1 to 140.5.63.254140.5.63.2558,190
43140.5.64.0/19140.5.64.1 to 140.5.95.254140.5.95.2558,190
44140.5.96.0/19140.5.96.1 to 140.5.127.254140.5.127.2558,190
45140.5.128.0/19140.5.128.1 to 140.5.159.254140.5.159.2558,190
46140.5.160.0/19140.5.160.1 to 140.5.191.254140.5.191.2558,190
47140.5.192.0/19140.5.192.1 to 140.5.223.254140.5.223.2558,190
48140.5.224.0/19140.5.224.1 to 140.5.255.254140.5.255.2558,190
49140.6.0.0/19140.6.0.1 to 140.6.31.254140.6.31.2558,190
50140.6.32.0/19140.6.32.1 to 140.6.63.254140.6.63.2558,190
51140.6.64.0/19140.6.64.1 to 140.6.95.254140.6.95.2558,190
52140.6.96.0/19140.6.96.1 to 140.6.127.254140.6.127.2558,190
53140.6.128.0/19140.6.128.1 to 140.6.159.254140.6.159.2558,190
54140.6.160.0/19140.6.160.1 to 140.6.191.254140.6.191.2558,190
55140.6.192.0/19140.6.192.1 to 140.6.223.254140.6.223.2558,190
56140.6.224.0/19140.6.224.1 to 140.6.255.254140.6.255.2558,190
57140.7.0.0/19140.7.0.1 to 140.7.31.254140.7.31.2558,190
58140.7.32.0/19140.7.32.1 to 140.7.63.254140.7.63.2558,190
59140.7.64.0/19140.7.64.1 to 140.7.95.254140.7.95.2558,190
60140.7.96.0/19140.7.96.1 to 140.7.127.254140.7.127.2558,190
61140.7.128.0/19140.7.128.1 to 140.7.159.254140.7.159.2558,190
62140.7.160.0/19140.7.160.1 to 140.7.191.254140.7.191.2558,190
63140.7.192.0/19140.7.192.1 to 140.7.223.254140.7.223.2558,190
64140.7.224.0/19140.7.224.1 to 140.7.255.254140.7.255.2558,190
65140.8.0.0/19140.8.0.1 to 140.8.31.254140.8.31.2558,190
66140.8.32.0/19140.8.32.1 to 140.8.63.254140.8.63.2558,190
67140.8.64.0/19140.8.64.1 to 140.8.95.254140.8.95.2558,190
68140.8.96.0/19140.8.96.1 to 140.8.127.254140.8.127.2558,190
69140.8.128.0/19140.8.128.1 to 140.8.159.254140.8.159.2558,190
70140.8.160.0/19140.8.160.1 to 140.8.191.254140.8.191.2558,190
71140.8.192.0/19140.8.192.1 to 140.8.223.254140.8.223.2558,190
72140.8.224.0/19140.8.224.1 to 140.8.255.254140.8.255.2558,190
73140.9.0.0/19140.9.0.1 to 140.9.31.254140.9.31.2558,190
74140.9.32.0/19140.9.32.1 to 140.9.63.254140.9.63.2558,190
75140.9.64.0/19140.9.64.1 to 140.9.95.254140.9.95.2558,190
76140.9.96.0/19140.9.96.1 to 140.9.127.254140.9.127.2558,190
77140.9.128.0/19140.9.128.1 to 140.9.159.254140.9.159.2558,190
78140.9.160.0/19140.9.160.1 to 140.9.191.254140.9.191.2558,190
79140.9.192.0/19140.9.192.1 to 140.9.223.254140.9.223.2558,190
80140.9.224.0/19140.9.224.1 to 140.9.255.254140.9.255.2558,190
81140.10.0.0/19140.10.0.1 to 140.10.31.254140.10.31.2558,190
82140.10.32.0/19140.10.32.1 to 140.10.63.254140.10.63.2558,190
83140.10.64.0/19140.10.64.1 to 140.10.95.254140.10.95.2558,190
84140.10.96.0/19140.10.96.1 to 140.10.127.254140.10.127.2558,190
85140.10.128.0/19140.10.128.1 to 140.10.159.254140.10.159.2558,190
86140.10.160.0/19140.10.160.1 to 140.10.191.254140.10.191.2558,190
87140.10.192.0/19140.10.192.1 to 140.10.223.254140.10.223.2558,190
88140.10.224.0/19140.10.224.1 to 140.10.255.254140.10.255.2558,190
89140.11.0.0/19140.11.0.1 to 140.11.31.254140.11.31.2558,190
90140.11.32.0/19140.11.32.1 to 140.11.63.254140.11.63.2558,190
91140.11.64.0/19140.11.64.1 to 140.11.95.254140.11.95.2558,190
92140.11.96.0/19140.11.96.1 to 140.11.127.254140.11.127.2558,190
93140.11.128.0/19140.11.128.1 to 140.11.159.254140.11.159.2558,190
94140.11.160.0/19140.11.160.1 to 140.11.191.254140.11.191.2558,190
95140.11.192.0/19140.11.192.1 to 140.11.223.254140.11.223.2558,190
96140.11.224.0/19140.11.224.1 to 140.11.255.254140.11.255.2558,190
97140.12.0.0/19140.12.0.1 to 140.12.31.254140.12.31.2558,190
98140.12.32.0/19140.12.32.1 to 140.12.63.254140.12.63.2558,190
99140.12.64.0/19140.12.64.1 to 140.12.95.254140.12.95.2558,190
100140.12.96.0/19140.12.96.1 to 140.12.127.254140.12.127.2558,190
101140.12.128.0/19140.12.128.1 to 140.12.159.254140.12.159.2558,190
102140.12.160.0/19140.12.160.1 to 140.12.191.254140.12.191.2558,190
103140.12.192.0/19140.12.192.1 to 140.12.223.254140.12.223.2558,190
104140.12.224.0/19140.12.224.1 to 140.12.255.254140.12.255.2558,190
105140.13.0.0/19140.13.0.1 to 140.13.31.254140.13.31.2558,190
106140.13.32.0/19140.13.32.1 to 140.13.63.254140.13.63.2558,190
107140.13.64.0/19140.13.64.1 to 140.13.95.254140.13.95.2558,190
108140.13.96.0/19140.13.96.1 to 140.13.127.254140.13.127.2558,190
109140.13.128.0/19140.13.128.1 to 140.13.159.254140.13.159.2558,190
110140.13.160.0/19140.13.160.1 to 140.13.191.254140.13.191.2558,190
111140.13.192.0/19140.13.192.1 to 140.13.223.254140.13.223.2558,190
112140.13.224.0/19140.13.224.1 to 140.13.255.254140.13.255.2558,190
113140.14.0.0/19140.14.0.1 to 140.14.31.254140.14.31.2558,190
114140.14.32.0/19140.14.32.1 to 140.14.63.254140.14.63.2558,190
115140.14.64.0/19140.14.64.1 to 140.14.95.254140.14.95.2558,190
116140.14.96.0/19140.14.96.1 to 140.14.127.254140.14.127.2558,190
117140.14.128.0/19140.14.128.1 to 140.14.159.254140.14.159.2558,190
118140.14.160.0/19140.14.160.1 to 140.14.191.254140.14.191.2558,190
119140.14.192.0/19140.14.192.1 to 140.14.223.254140.14.223.2558,190
120140.14.224.0/19140.14.224.1 to 140.14.255.254140.14.255.2558,190
121140.15.0.0/19140.15.0.1 to 140.15.31.254140.15.31.2558,190
122140.15.32.0/19140.15.32.1 to 140.15.63.254140.15.63.2558,190
123140.15.64.0/19140.15.64.1 to 140.15.95.254140.15.95.2558,190
124140.15.96.0/19140.15.96.1 to 140.15.127.254140.15.127.2558,190
125140.15.128.0/19140.15.128.1 to 140.15.159.254140.15.159.2558,190
126140.15.160.0/19140.15.160.1 to 140.15.191.254140.15.191.2558,190
127140.15.192.0/19140.15.192.1 to 140.15.223.254140.15.223.2558,190
128140.15.224.0/19140.15.224.1 to 140.15.255.254140.15.255.2558,190
129140.16.0.0/19140.16.0.1 to 140.16.31.254140.16.31.2558,190
130140.16.32.0/19140.16.32.1 to 140.16.63.254140.16.63.2558,190
131140.16.64.0/19140.16.64.1 to 140.16.95.254140.16.95.2558,190
132140.16.96.0/19140.16.96.1 to 140.16.127.254140.16.127.2558,190
133140.16.128.0/19140.16.128.1 to 140.16.159.254140.16.159.2558,190
134140.16.160.0/19140.16.160.1 to 140.16.191.254140.16.191.2558,190
135140.16.192.0/19140.16.192.1 to 140.16.223.254140.16.223.2558,190
136140.16.224.0/19140.16.224.1 to 140.16.255.254140.16.255.2558,190
137140.17.0.0/19140.17.0.1 to 140.17.31.254140.17.31.2558,190
138140.17.32.0/19140.17.32.1 to 140.17.63.254140.17.63.2558,190
139140.17.64.0/19140.17.64.1 to 140.17.95.254140.17.95.2558,190
140140.17.96.0/19140.17.96.1 to 140.17.127.254140.17.127.2558,190
141140.17.128.0/19140.17.128.1 to 140.17.159.254140.17.159.2558,190
142140.17.160.0/19140.17.160.1 to 140.17.191.254140.17.191.2558,190
143140.17.192.0/19140.17.192.1 to 140.17.223.254140.17.223.2558,190
144140.17.224.0/19140.17.224.1 to 140.17.255.254140.17.255.2558,190
145140.18.0.0/19140.18.0.1 to 140.18.31.254140.18.31.2558,190
146140.18.32.0/19140.18.32.1 to 140.18.63.254140.18.63.2558,190
147140.18.64.0/19140.18.64.1 to 140.18.95.254140.18.95.2558,190
148140.18.96.0/19140.18.96.1 to 140.18.127.254140.18.127.2558,190
149140.18.128.0/19140.18.128.1 to 140.18.159.254140.18.159.2558,190
150140.18.160.0/19140.18.160.1 to 140.18.191.254140.18.191.2558,190
151140.18.192.0/19140.18.192.1 to 140.18.223.254140.18.223.2558,190
152140.18.224.0/19140.18.224.1 to 140.18.255.254140.18.255.2558,190
153140.19.0.0/19140.19.0.1 to 140.19.31.254140.19.31.2558,190
154140.19.32.0/19140.19.32.1 to 140.19.63.254140.19.63.2558,190
155140.19.64.0/19140.19.64.1 to 140.19.95.254140.19.95.2558,190
156140.19.96.0/19140.19.96.1 to 140.19.127.254140.19.127.2558,190
157140.19.128.0/19140.19.128.1 to 140.19.159.254140.19.159.2558,190
158140.19.160.0/19140.19.160.1 to 140.19.191.254140.19.191.2558,190
159140.19.192.0/19140.19.192.1 to 140.19.223.254140.19.223.2558,190
160140.19.224.0/19140.19.224.1 to 140.19.255.254140.19.255.2558,190
161140.20.0.0/19140.20.0.1 to 140.20.31.254140.20.31.2558,190
162140.20.32.0/19140.20.32.1 to 140.20.63.254140.20.63.2558,190
163140.20.64.0/19140.20.64.1 to 140.20.95.254140.20.95.2558,190
164140.20.96.0/19140.20.96.1 to 140.20.127.254140.20.127.2558,190
165140.20.128.0/19140.20.128.1 to 140.20.159.254140.20.159.2558,190
166140.20.160.0/19140.20.160.1 to 140.20.191.254140.20.191.2558,190
167140.20.192.0/19140.20.192.1 to 140.20.223.254140.20.223.2558,190
168140.20.224.0/19140.20.224.1 to 140.20.255.254140.20.255.2558,190
169140.21.0.0/19140.21.0.1 to 140.21.31.254140.21.31.2558,190
170140.21.32.0/19140.21.32.1 to 140.21.63.254140.21.63.2558,190
171140.21.64.0/19140.21.64.1 to 140.21.95.254140.21.95.2558,190
172140.21.96.0/19140.21.96.1 to 140.21.127.254140.21.127.2558,190
173140.21.128.0/19140.21.128.1 to 140.21.159.254140.21.159.2558,190
174140.21.160.0/19140.21.160.1 to 140.21.191.254140.21.191.2558,190
175140.21.192.0/19140.21.192.1 to 140.21.223.254140.21.223.2558,190
176140.21.224.0/19140.21.224.1 to 140.21.255.254140.21.255.2558,190
177140.22.0.0/19140.22.0.1 to 140.22.31.254140.22.31.2558,190
178140.22.32.0/19140.22.32.1 to 140.22.63.254140.22.63.2558,190
179140.22.64.0/19140.22.64.1 to 140.22.95.254140.22.95.2558,190
180140.22.96.0/19140.22.96.1 to 140.22.127.254140.22.127.2558,190
181140.22.128.0/19140.22.128.1 to 140.22.159.254140.22.159.2558,190
182140.22.160.0/19140.22.160.1 to 140.22.191.254140.22.191.2558,190
183140.22.192.0/19140.22.192.1 to 140.22.223.254140.22.223.2558,190
184140.22.224.0/19140.22.224.1 to 140.22.255.254140.22.255.2558,190
185140.23.0.0/19140.23.0.1 to 140.23.31.254140.23.31.2558,190
186140.23.32.0/19140.23.32.1 to 140.23.63.254140.23.63.2558,190
187140.23.64.0/19140.23.64.1 to 140.23.95.254140.23.95.2558,190
188140.23.96.0/19140.23.96.1 to 140.23.127.254140.23.127.2558,190
189140.23.128.0/19140.23.128.1 to 140.23.159.254140.23.159.2558,190
190140.23.160.0/19140.23.160.1 to 140.23.191.254140.23.191.2558,190
191140.23.192.0/19140.23.192.1 to 140.23.223.254140.23.223.2558,190
192140.23.224.0/19140.23.224.1 to 140.23.255.254140.23.255.2558,190
193140.24.0.0/19140.24.0.1 to 140.24.31.254140.24.31.2558,190
194140.24.32.0/19140.24.32.1 to 140.24.63.254140.24.63.2558,190
195140.24.64.0/19140.24.64.1 to 140.24.95.254140.24.95.2558,190
196140.24.96.0/19140.24.96.1 to 140.24.127.254140.24.127.2558,190
197140.24.128.0/19140.24.128.1 to 140.24.159.254140.24.159.2558,190
198140.24.160.0/19140.24.160.1 to 140.24.191.254140.24.191.2558,190
199140.24.192.0/19140.24.192.1 to 140.24.223.254140.24.223.2558,190
200140.24.224.0/19140.24.224.1 to 140.24.255.254140.24.255.2558,190
201140.25.0.0/19140.25.0.1 to 140.25.31.254140.25.31.2558,190
202140.25.32.0/19140.25.32.1 to 140.25.63.254140.25.63.2558,190
203140.25.64.0/19140.25.64.1 to 140.25.95.254140.25.95.2558,190
204140.25.96.0/19140.25.96.1 to 140.25.127.254140.25.127.2558,190
205140.25.128.0/19140.25.128.1 to 140.25.159.254140.25.159.2558,190
206140.25.160.0/19140.25.160.1 to 140.25.191.254140.25.191.2558,190
207140.25.192.0/19140.25.192.1 to 140.25.223.254140.25.223.2558,190
208140.25.224.0/19140.25.224.1 to 140.25.255.254140.25.255.2558,190
209140.26.0.0/19140.26.0.1 to 140.26.31.254140.26.31.2558,190
210140.26.32.0/19140.26.32.1 to 140.26.63.254140.26.63.2558,190
211140.26.64.0/19140.26.64.1 to 140.26.95.254140.26.95.2558,190
212140.26.96.0/19140.26.96.1 to 140.26.127.254140.26.127.2558,190
213140.26.128.0/19140.26.128.1 to 140.26.159.254140.26.159.2558,190
214140.26.160.0/19140.26.160.1 to 140.26.191.254140.26.191.2558,190
215140.26.192.0/19140.26.192.1 to 140.26.223.254140.26.223.2558,190
216140.26.224.0/19140.26.224.1 to 140.26.255.254140.26.255.2558,190
217140.27.0.0/19140.27.0.1 to 140.27.31.254140.27.31.2558,190
218140.27.32.0/19140.27.32.1 to 140.27.63.254140.27.63.2558,190
219140.27.64.0/19140.27.64.1 to 140.27.95.254140.27.95.2558,190
220140.27.96.0/19140.27.96.1 to 140.27.127.254140.27.127.2558,190
221140.27.128.0/19140.27.128.1 to 140.27.159.254140.27.159.2558,190
222140.27.160.0/19140.27.160.1 to 140.27.191.254140.27.191.2558,190
223140.27.192.0/19140.27.192.1 to 140.27.223.254140.27.223.2558,190
224140.27.224.0/19140.27.224.1 to 140.27.255.254140.27.255.2558,190
225140.28.0.0/19140.28.0.1 to 140.28.31.254140.28.31.2558,190
226140.28.32.0/19140.28.32.1 to 140.28.63.254140.28.63.2558,190
227140.28.64.0/19140.28.64.1 to 140.28.95.254140.28.95.2558,190
228140.28.96.0/19140.28.96.1 to 140.28.127.254140.28.127.2558,190
229140.28.128.0/19140.28.128.1 to 140.28.159.254140.28.159.2558,190
230140.28.160.0/19140.28.160.1 to 140.28.191.254140.28.191.2558,190
231140.28.192.0/19140.28.192.1 to 140.28.223.254140.28.223.2558,190
232140.28.224.0/19140.28.224.1 to 140.28.255.254140.28.255.2558,190
233140.29.0.0/19140.29.0.1 to 140.29.31.254140.29.31.2558,190
234140.29.32.0/19140.29.32.1 to 140.29.63.254140.29.63.2558,190
235140.29.64.0/19140.29.64.1 to 140.29.95.254140.29.95.2558,190
236140.29.96.0/19140.29.96.1 to 140.29.127.254140.29.127.2558,190
237140.29.128.0/19140.29.128.1 to 140.29.159.254140.29.159.2558,190
238140.29.160.0/19140.29.160.1 to 140.29.191.254140.29.191.2558,190
239140.29.192.0/19140.29.192.1 to 140.29.223.254140.29.223.2558,190
240140.29.224.0/19140.29.224.1 to 140.29.255.254140.29.255.2558,190
241140.30.0.0/19140.30.0.1 to 140.30.31.254140.30.31.2558,190
242140.30.32.0/19140.30.32.1 to 140.30.63.254140.30.63.2558,190
243140.30.64.0/19140.30.64.1 to 140.30.95.254140.30.95.2558,190
244140.30.96.0/19140.30.96.1 to 140.30.127.254140.30.127.2558,190
245140.30.128.0/19140.30.128.1 to 140.30.159.254140.30.159.2558,190
246140.30.160.0/19140.30.160.1 to 140.30.191.254140.30.191.2558,190
247140.30.192.0/19140.30.192.1 to 140.30.223.254140.30.223.2558,190
248140.30.224.0/19140.30.224.1 to 140.30.255.254140.30.255.2558,190
249140.31.0.0/19140.31.0.1 to 140.31.31.254140.31.31.2558,190
250140.31.32.0/19140.31.32.1 to 140.31.63.254140.31.63.2558,190
251140.31.64.0/19140.31.64.1 to 140.31.95.254140.31.95.2558,190
252140.31.96.0/19140.31.96.1 to 140.31.127.254140.31.127.2558,190
253140.31.128.0/19140.31.128.1 to 140.31.159.254140.31.159.2558,190
254140.31.160.0/19140.31.160.1 to 140.31.191.254140.31.191.2558,190
255140.31.192.0/19140.31.192.1 to 140.31.223.254140.31.223.2558,190
256140.31.224.0/19140.31.224.1 to 140.31.255.254140.31.255.2558,190

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.