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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.

Network159.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
159.0.0.0
Broadcast address
159.255.255.255
First usable
159.0.0.1
Last usable
159.255.255.254
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 9F000000 · Integer 2667577344 to 2684354559
Reverse DNS zone
159.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10011111..00000000.00000000.00000000159.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network10011111..00000000.00000000.00000000159.0.0.0
Broadcast10011111..11111111.11111111.11111111159.255.255.255
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)

159.0.0.0/8 makes 2,048 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1159.0.0.0/19159.0.0.1 to 159.0.31.254159.0.31.2558,190
2159.0.32.0/19159.0.32.1 to 159.0.63.254159.0.63.2558,190
3159.0.64.0/19159.0.64.1 to 159.0.95.254159.0.95.2558,190
4159.0.96.0/19159.0.96.1 to 159.0.127.254159.0.127.2558,190
5159.0.128.0/19159.0.128.1 to 159.0.159.254159.0.159.2558,190
6159.0.160.0/19159.0.160.1 to 159.0.191.254159.0.191.2558,190
7159.0.192.0/19159.0.192.1 to 159.0.223.254159.0.223.2558,190
8159.0.224.0/19159.0.224.1 to 159.0.255.254159.0.255.2558,190
9159.1.0.0/19159.1.0.1 to 159.1.31.254159.1.31.2558,190
10159.1.32.0/19159.1.32.1 to 159.1.63.254159.1.63.2558,190
11159.1.64.0/19159.1.64.1 to 159.1.95.254159.1.95.2558,190
12159.1.96.0/19159.1.96.1 to 159.1.127.254159.1.127.2558,190
13159.1.128.0/19159.1.128.1 to 159.1.159.254159.1.159.2558,190
14159.1.160.0/19159.1.160.1 to 159.1.191.254159.1.191.2558,190
15159.1.192.0/19159.1.192.1 to 159.1.223.254159.1.223.2558,190
16159.1.224.0/19159.1.224.1 to 159.1.255.254159.1.255.2558,190
17159.2.0.0/19159.2.0.1 to 159.2.31.254159.2.31.2558,190
18159.2.32.0/19159.2.32.1 to 159.2.63.254159.2.63.2558,190
19159.2.64.0/19159.2.64.1 to 159.2.95.254159.2.95.2558,190
20159.2.96.0/19159.2.96.1 to 159.2.127.254159.2.127.2558,190
21159.2.128.0/19159.2.128.1 to 159.2.159.254159.2.159.2558,190
22159.2.160.0/19159.2.160.1 to 159.2.191.254159.2.191.2558,190
23159.2.192.0/19159.2.192.1 to 159.2.223.254159.2.223.2558,190
24159.2.224.0/19159.2.224.1 to 159.2.255.254159.2.255.2558,190
25159.3.0.0/19159.3.0.1 to 159.3.31.254159.3.31.2558,190
26159.3.32.0/19159.3.32.1 to 159.3.63.254159.3.63.2558,190
27159.3.64.0/19159.3.64.1 to 159.3.95.254159.3.95.2558,190
28159.3.96.0/19159.3.96.1 to 159.3.127.254159.3.127.2558,190
29159.3.128.0/19159.3.128.1 to 159.3.159.254159.3.159.2558,190
30159.3.160.0/19159.3.160.1 to 159.3.191.254159.3.191.2558,190
31159.3.192.0/19159.3.192.1 to 159.3.223.254159.3.223.2558,190
32159.3.224.0/19159.3.224.1 to 159.3.255.254159.3.255.2558,190
33159.4.0.0/19159.4.0.1 to 159.4.31.254159.4.31.2558,190
34159.4.32.0/19159.4.32.1 to 159.4.63.254159.4.63.2558,190
35159.4.64.0/19159.4.64.1 to 159.4.95.254159.4.95.2558,190
36159.4.96.0/19159.4.96.1 to 159.4.127.254159.4.127.2558,190
37159.4.128.0/19159.4.128.1 to 159.4.159.254159.4.159.2558,190
38159.4.160.0/19159.4.160.1 to 159.4.191.254159.4.191.2558,190
39159.4.192.0/19159.4.192.1 to 159.4.223.254159.4.223.2558,190
40159.4.224.0/19159.4.224.1 to 159.4.255.254159.4.255.2558,190
41159.5.0.0/19159.5.0.1 to 159.5.31.254159.5.31.2558,190
42159.5.32.0/19159.5.32.1 to 159.5.63.254159.5.63.2558,190
43159.5.64.0/19159.5.64.1 to 159.5.95.254159.5.95.2558,190
44159.5.96.0/19159.5.96.1 to 159.5.127.254159.5.127.2558,190
45159.5.128.0/19159.5.128.1 to 159.5.159.254159.5.159.2558,190
46159.5.160.0/19159.5.160.1 to 159.5.191.254159.5.191.2558,190
47159.5.192.0/19159.5.192.1 to 159.5.223.254159.5.223.2558,190
48159.5.224.0/19159.5.224.1 to 159.5.255.254159.5.255.2558,190
49159.6.0.0/19159.6.0.1 to 159.6.31.254159.6.31.2558,190
50159.6.32.0/19159.6.32.1 to 159.6.63.254159.6.63.2558,190
51159.6.64.0/19159.6.64.1 to 159.6.95.254159.6.95.2558,190
52159.6.96.0/19159.6.96.1 to 159.6.127.254159.6.127.2558,190
53159.6.128.0/19159.6.128.1 to 159.6.159.254159.6.159.2558,190
54159.6.160.0/19159.6.160.1 to 159.6.191.254159.6.191.2558,190
55159.6.192.0/19159.6.192.1 to 159.6.223.254159.6.223.2558,190
56159.6.224.0/19159.6.224.1 to 159.6.255.254159.6.255.2558,190
57159.7.0.0/19159.7.0.1 to 159.7.31.254159.7.31.2558,190
58159.7.32.0/19159.7.32.1 to 159.7.63.254159.7.63.2558,190
59159.7.64.0/19159.7.64.1 to 159.7.95.254159.7.95.2558,190
60159.7.96.0/19159.7.96.1 to 159.7.127.254159.7.127.2558,190
61159.7.128.0/19159.7.128.1 to 159.7.159.254159.7.159.2558,190
62159.7.160.0/19159.7.160.1 to 159.7.191.254159.7.191.2558,190
63159.7.192.0/19159.7.192.1 to 159.7.223.254159.7.223.2558,190
64159.7.224.0/19159.7.224.1 to 159.7.255.254159.7.255.2558,190
65159.8.0.0/19159.8.0.1 to 159.8.31.254159.8.31.2558,190
66159.8.32.0/19159.8.32.1 to 159.8.63.254159.8.63.2558,190
67159.8.64.0/19159.8.64.1 to 159.8.95.254159.8.95.2558,190
68159.8.96.0/19159.8.96.1 to 159.8.127.254159.8.127.2558,190
69159.8.128.0/19159.8.128.1 to 159.8.159.254159.8.159.2558,190
70159.8.160.0/19159.8.160.1 to 159.8.191.254159.8.191.2558,190
71159.8.192.0/19159.8.192.1 to 159.8.223.254159.8.223.2558,190
72159.8.224.0/19159.8.224.1 to 159.8.255.254159.8.255.2558,190
73159.9.0.0/19159.9.0.1 to 159.9.31.254159.9.31.2558,190
74159.9.32.0/19159.9.32.1 to 159.9.63.254159.9.63.2558,190
75159.9.64.0/19159.9.64.1 to 159.9.95.254159.9.95.2558,190
76159.9.96.0/19159.9.96.1 to 159.9.127.254159.9.127.2558,190
77159.9.128.0/19159.9.128.1 to 159.9.159.254159.9.159.2558,190
78159.9.160.0/19159.9.160.1 to 159.9.191.254159.9.191.2558,190
79159.9.192.0/19159.9.192.1 to 159.9.223.254159.9.223.2558,190
80159.9.224.0/19159.9.224.1 to 159.9.255.254159.9.255.2558,190
81159.10.0.0/19159.10.0.1 to 159.10.31.254159.10.31.2558,190
82159.10.32.0/19159.10.32.1 to 159.10.63.254159.10.63.2558,190
83159.10.64.0/19159.10.64.1 to 159.10.95.254159.10.95.2558,190
84159.10.96.0/19159.10.96.1 to 159.10.127.254159.10.127.2558,190
85159.10.128.0/19159.10.128.1 to 159.10.159.254159.10.159.2558,190
86159.10.160.0/19159.10.160.1 to 159.10.191.254159.10.191.2558,190
87159.10.192.0/19159.10.192.1 to 159.10.223.254159.10.223.2558,190
88159.10.224.0/19159.10.224.1 to 159.10.255.254159.10.255.2558,190
89159.11.0.0/19159.11.0.1 to 159.11.31.254159.11.31.2558,190
90159.11.32.0/19159.11.32.1 to 159.11.63.254159.11.63.2558,190
91159.11.64.0/19159.11.64.1 to 159.11.95.254159.11.95.2558,190
92159.11.96.0/19159.11.96.1 to 159.11.127.254159.11.127.2558,190
93159.11.128.0/19159.11.128.1 to 159.11.159.254159.11.159.2558,190
94159.11.160.0/19159.11.160.1 to 159.11.191.254159.11.191.2558,190
95159.11.192.0/19159.11.192.1 to 159.11.223.254159.11.223.2558,190
96159.11.224.0/19159.11.224.1 to 159.11.255.254159.11.255.2558,190
97159.12.0.0/19159.12.0.1 to 159.12.31.254159.12.31.2558,190
98159.12.32.0/19159.12.32.1 to 159.12.63.254159.12.63.2558,190
99159.12.64.0/19159.12.64.1 to 159.12.95.254159.12.95.2558,190
100159.12.96.0/19159.12.96.1 to 159.12.127.254159.12.127.2558,190
101159.12.128.0/19159.12.128.1 to 159.12.159.254159.12.159.2558,190
102159.12.160.0/19159.12.160.1 to 159.12.191.254159.12.191.2558,190
103159.12.192.0/19159.12.192.1 to 159.12.223.254159.12.223.2558,190
104159.12.224.0/19159.12.224.1 to 159.12.255.254159.12.255.2558,190
105159.13.0.0/19159.13.0.1 to 159.13.31.254159.13.31.2558,190
106159.13.32.0/19159.13.32.1 to 159.13.63.254159.13.63.2558,190
107159.13.64.0/19159.13.64.1 to 159.13.95.254159.13.95.2558,190
108159.13.96.0/19159.13.96.1 to 159.13.127.254159.13.127.2558,190
109159.13.128.0/19159.13.128.1 to 159.13.159.254159.13.159.2558,190
110159.13.160.0/19159.13.160.1 to 159.13.191.254159.13.191.2558,190
111159.13.192.0/19159.13.192.1 to 159.13.223.254159.13.223.2558,190
112159.13.224.0/19159.13.224.1 to 159.13.255.254159.13.255.2558,190
113159.14.0.0/19159.14.0.1 to 159.14.31.254159.14.31.2558,190
114159.14.32.0/19159.14.32.1 to 159.14.63.254159.14.63.2558,190
115159.14.64.0/19159.14.64.1 to 159.14.95.254159.14.95.2558,190
116159.14.96.0/19159.14.96.1 to 159.14.127.254159.14.127.2558,190
117159.14.128.0/19159.14.128.1 to 159.14.159.254159.14.159.2558,190
118159.14.160.0/19159.14.160.1 to 159.14.191.254159.14.191.2558,190
119159.14.192.0/19159.14.192.1 to 159.14.223.254159.14.223.2558,190
120159.14.224.0/19159.14.224.1 to 159.14.255.254159.14.255.2558,190
121159.15.0.0/19159.15.0.1 to 159.15.31.254159.15.31.2558,190
122159.15.32.0/19159.15.32.1 to 159.15.63.254159.15.63.2558,190
123159.15.64.0/19159.15.64.1 to 159.15.95.254159.15.95.2558,190
124159.15.96.0/19159.15.96.1 to 159.15.127.254159.15.127.2558,190
125159.15.128.0/19159.15.128.1 to 159.15.159.254159.15.159.2558,190
126159.15.160.0/19159.15.160.1 to 159.15.191.254159.15.191.2558,190
127159.15.192.0/19159.15.192.1 to 159.15.223.254159.15.223.2558,190
128159.15.224.0/19159.15.224.1 to 159.15.255.254159.15.255.2558,190
129159.16.0.0/19159.16.0.1 to 159.16.31.254159.16.31.2558,190
130159.16.32.0/19159.16.32.1 to 159.16.63.254159.16.63.2558,190
131159.16.64.0/19159.16.64.1 to 159.16.95.254159.16.95.2558,190
132159.16.96.0/19159.16.96.1 to 159.16.127.254159.16.127.2558,190
133159.16.128.0/19159.16.128.1 to 159.16.159.254159.16.159.2558,190
134159.16.160.0/19159.16.160.1 to 159.16.191.254159.16.191.2558,190
135159.16.192.0/19159.16.192.1 to 159.16.223.254159.16.223.2558,190
136159.16.224.0/19159.16.224.1 to 159.16.255.254159.16.255.2558,190
137159.17.0.0/19159.17.0.1 to 159.17.31.254159.17.31.2558,190
138159.17.32.0/19159.17.32.1 to 159.17.63.254159.17.63.2558,190
139159.17.64.0/19159.17.64.1 to 159.17.95.254159.17.95.2558,190
140159.17.96.0/19159.17.96.1 to 159.17.127.254159.17.127.2558,190
141159.17.128.0/19159.17.128.1 to 159.17.159.254159.17.159.2558,190
142159.17.160.0/19159.17.160.1 to 159.17.191.254159.17.191.2558,190
143159.17.192.0/19159.17.192.1 to 159.17.223.254159.17.223.2558,190
144159.17.224.0/19159.17.224.1 to 159.17.255.254159.17.255.2558,190
145159.18.0.0/19159.18.0.1 to 159.18.31.254159.18.31.2558,190
146159.18.32.0/19159.18.32.1 to 159.18.63.254159.18.63.2558,190
147159.18.64.0/19159.18.64.1 to 159.18.95.254159.18.95.2558,190
148159.18.96.0/19159.18.96.1 to 159.18.127.254159.18.127.2558,190
149159.18.128.0/19159.18.128.1 to 159.18.159.254159.18.159.2558,190
150159.18.160.0/19159.18.160.1 to 159.18.191.254159.18.191.2558,190
151159.18.192.0/19159.18.192.1 to 159.18.223.254159.18.223.2558,190
152159.18.224.0/19159.18.224.1 to 159.18.255.254159.18.255.2558,190
153159.19.0.0/19159.19.0.1 to 159.19.31.254159.19.31.2558,190
154159.19.32.0/19159.19.32.1 to 159.19.63.254159.19.63.2558,190
155159.19.64.0/19159.19.64.1 to 159.19.95.254159.19.95.2558,190
156159.19.96.0/19159.19.96.1 to 159.19.127.254159.19.127.2558,190
157159.19.128.0/19159.19.128.1 to 159.19.159.254159.19.159.2558,190
158159.19.160.0/19159.19.160.1 to 159.19.191.254159.19.191.2558,190
159159.19.192.0/19159.19.192.1 to 159.19.223.254159.19.223.2558,190
160159.19.224.0/19159.19.224.1 to 159.19.255.254159.19.255.2558,190
161159.20.0.0/19159.20.0.1 to 159.20.31.254159.20.31.2558,190
162159.20.32.0/19159.20.32.1 to 159.20.63.254159.20.63.2558,190
163159.20.64.0/19159.20.64.1 to 159.20.95.254159.20.95.2558,190
164159.20.96.0/19159.20.96.1 to 159.20.127.254159.20.127.2558,190
165159.20.128.0/19159.20.128.1 to 159.20.159.254159.20.159.2558,190
166159.20.160.0/19159.20.160.1 to 159.20.191.254159.20.191.2558,190
167159.20.192.0/19159.20.192.1 to 159.20.223.254159.20.223.2558,190
168159.20.224.0/19159.20.224.1 to 159.20.255.254159.20.255.2558,190
169159.21.0.0/19159.21.0.1 to 159.21.31.254159.21.31.2558,190
170159.21.32.0/19159.21.32.1 to 159.21.63.254159.21.63.2558,190
171159.21.64.0/19159.21.64.1 to 159.21.95.254159.21.95.2558,190
172159.21.96.0/19159.21.96.1 to 159.21.127.254159.21.127.2558,190
173159.21.128.0/19159.21.128.1 to 159.21.159.254159.21.159.2558,190
174159.21.160.0/19159.21.160.1 to 159.21.191.254159.21.191.2558,190
175159.21.192.0/19159.21.192.1 to 159.21.223.254159.21.223.2558,190
176159.21.224.0/19159.21.224.1 to 159.21.255.254159.21.255.2558,190
177159.22.0.0/19159.22.0.1 to 159.22.31.254159.22.31.2558,190
178159.22.32.0/19159.22.32.1 to 159.22.63.254159.22.63.2558,190
179159.22.64.0/19159.22.64.1 to 159.22.95.254159.22.95.2558,190
180159.22.96.0/19159.22.96.1 to 159.22.127.254159.22.127.2558,190
181159.22.128.0/19159.22.128.1 to 159.22.159.254159.22.159.2558,190
182159.22.160.0/19159.22.160.1 to 159.22.191.254159.22.191.2558,190
183159.22.192.0/19159.22.192.1 to 159.22.223.254159.22.223.2558,190
184159.22.224.0/19159.22.224.1 to 159.22.255.254159.22.255.2558,190
185159.23.0.0/19159.23.0.1 to 159.23.31.254159.23.31.2558,190
186159.23.32.0/19159.23.32.1 to 159.23.63.254159.23.63.2558,190
187159.23.64.0/19159.23.64.1 to 159.23.95.254159.23.95.2558,190
188159.23.96.0/19159.23.96.1 to 159.23.127.254159.23.127.2558,190
189159.23.128.0/19159.23.128.1 to 159.23.159.254159.23.159.2558,190
190159.23.160.0/19159.23.160.1 to 159.23.191.254159.23.191.2558,190
191159.23.192.0/19159.23.192.1 to 159.23.223.254159.23.223.2558,190
192159.23.224.0/19159.23.224.1 to 159.23.255.254159.23.255.2558,190
193159.24.0.0/19159.24.0.1 to 159.24.31.254159.24.31.2558,190
194159.24.32.0/19159.24.32.1 to 159.24.63.254159.24.63.2558,190
195159.24.64.0/19159.24.64.1 to 159.24.95.254159.24.95.2558,190
196159.24.96.0/19159.24.96.1 to 159.24.127.254159.24.127.2558,190
197159.24.128.0/19159.24.128.1 to 159.24.159.254159.24.159.2558,190
198159.24.160.0/19159.24.160.1 to 159.24.191.254159.24.191.2558,190
199159.24.192.0/19159.24.192.1 to 159.24.223.254159.24.223.2558,190
200159.24.224.0/19159.24.224.1 to 159.24.255.254159.24.255.2558,190
201159.25.0.0/19159.25.0.1 to 159.25.31.254159.25.31.2558,190
202159.25.32.0/19159.25.32.1 to 159.25.63.254159.25.63.2558,190
203159.25.64.0/19159.25.64.1 to 159.25.95.254159.25.95.2558,190
204159.25.96.0/19159.25.96.1 to 159.25.127.254159.25.127.2558,190
205159.25.128.0/19159.25.128.1 to 159.25.159.254159.25.159.2558,190
206159.25.160.0/19159.25.160.1 to 159.25.191.254159.25.191.2558,190
207159.25.192.0/19159.25.192.1 to 159.25.223.254159.25.223.2558,190
208159.25.224.0/19159.25.224.1 to 159.25.255.254159.25.255.2558,190
209159.26.0.0/19159.26.0.1 to 159.26.31.254159.26.31.2558,190
210159.26.32.0/19159.26.32.1 to 159.26.63.254159.26.63.2558,190
211159.26.64.0/19159.26.64.1 to 159.26.95.254159.26.95.2558,190
212159.26.96.0/19159.26.96.1 to 159.26.127.254159.26.127.2558,190
213159.26.128.0/19159.26.128.1 to 159.26.159.254159.26.159.2558,190
214159.26.160.0/19159.26.160.1 to 159.26.191.254159.26.191.2558,190
215159.26.192.0/19159.26.192.1 to 159.26.223.254159.26.223.2558,190
216159.26.224.0/19159.26.224.1 to 159.26.255.254159.26.255.2558,190
217159.27.0.0/19159.27.0.1 to 159.27.31.254159.27.31.2558,190
218159.27.32.0/19159.27.32.1 to 159.27.63.254159.27.63.2558,190
219159.27.64.0/19159.27.64.1 to 159.27.95.254159.27.95.2558,190
220159.27.96.0/19159.27.96.1 to 159.27.127.254159.27.127.2558,190
221159.27.128.0/19159.27.128.1 to 159.27.159.254159.27.159.2558,190
222159.27.160.0/19159.27.160.1 to 159.27.191.254159.27.191.2558,190
223159.27.192.0/19159.27.192.1 to 159.27.223.254159.27.223.2558,190
224159.27.224.0/19159.27.224.1 to 159.27.255.254159.27.255.2558,190
225159.28.0.0/19159.28.0.1 to 159.28.31.254159.28.31.2558,190
226159.28.32.0/19159.28.32.1 to 159.28.63.254159.28.63.2558,190
227159.28.64.0/19159.28.64.1 to 159.28.95.254159.28.95.2558,190
228159.28.96.0/19159.28.96.1 to 159.28.127.254159.28.127.2558,190
229159.28.128.0/19159.28.128.1 to 159.28.159.254159.28.159.2558,190
230159.28.160.0/19159.28.160.1 to 159.28.191.254159.28.191.2558,190
231159.28.192.0/19159.28.192.1 to 159.28.223.254159.28.223.2558,190
232159.28.224.0/19159.28.224.1 to 159.28.255.254159.28.255.2558,190
233159.29.0.0/19159.29.0.1 to 159.29.31.254159.29.31.2558,190
234159.29.32.0/19159.29.32.1 to 159.29.63.254159.29.63.2558,190
235159.29.64.0/19159.29.64.1 to 159.29.95.254159.29.95.2558,190
236159.29.96.0/19159.29.96.1 to 159.29.127.254159.29.127.2558,190
237159.29.128.0/19159.29.128.1 to 159.29.159.254159.29.159.2558,190
238159.29.160.0/19159.29.160.1 to 159.29.191.254159.29.191.2558,190
239159.29.192.0/19159.29.192.1 to 159.29.223.254159.29.223.2558,190
240159.29.224.0/19159.29.224.1 to 159.29.255.254159.29.255.2558,190
241159.30.0.0/19159.30.0.1 to 159.30.31.254159.30.31.2558,190
242159.30.32.0/19159.30.32.1 to 159.30.63.254159.30.63.2558,190
243159.30.64.0/19159.30.64.1 to 159.30.95.254159.30.95.2558,190
244159.30.96.0/19159.30.96.1 to 159.30.127.254159.30.127.2558,190
245159.30.128.0/19159.30.128.1 to 159.30.159.254159.30.159.2558,190
246159.30.160.0/19159.30.160.1 to 159.30.191.254159.30.191.2558,190
247159.30.192.0/19159.30.192.1 to 159.30.223.254159.30.223.2558,190
248159.30.224.0/19159.30.224.1 to 159.30.255.254159.30.255.2558,190
249159.31.0.0/19159.31.0.1 to 159.31.31.254159.31.31.2558,190
250159.31.32.0/19159.31.32.1 to 159.31.63.254159.31.63.2558,190
251159.31.64.0/19159.31.64.1 to 159.31.95.254159.31.95.2558,190
252159.31.96.0/19159.31.96.1 to 159.31.127.254159.31.127.2558,190
253159.31.128.0/19159.31.128.1 to 159.31.159.254159.31.159.2558,190
254159.31.160.0/19159.31.160.1 to 159.31.191.254159.31.191.2558,190
255159.31.192.0/19159.31.192.1 to 159.31.223.254159.31.223.2558,190
256159.31.224.0/19159.31.224.1 to 159.31.255.254159.31.255.2558,190

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.