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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.

Network162.97.0.0/17
Usable hosts32,766
Subnet mask255.255.128.0
Addresses32,768
Network address
162.97.0.0
Broadcast address
162.97.127.255
First usable
162.97.0.1
Last usable
162.97.127.254
Usable hosts
32,766 (32,768 less the network and broadcast addresses)
Subnet mask
255.255.128.0
Wildcard mask
0.0.127.255 (Cisco ACLs, OSPF)
Prefix length
/17
Type
Public public
Old class
B (default /16)
As numbers
Hex A2610000 · Integer 2724265984 to 2724298751
Reverse DNS zones
0.97.162.in-addr.arpa
1.97.162.in-addr.arpa
2.97.162.in-addr.arpa
3.97.162.in-addr.arpa
4.97.162.in-addr.arpa
5.97.162.in-addr.arpa
6.97.162.in-addr.arpa
7.97.162.in-addr.arpa
8.97.162.in-addr.arpa
9.97.162.in-addr.arpa
10.97.162.in-addr.arpa
11.97.162.in-addr.arpa
12.97.162.in-addr.arpa
13.97.162.in-addr.arpa
14.97.162.in-addr.arpa
15.97.162.in-addr.arpa
and 112 more
/17 is not on a 8-bit boundary, so it takes 128 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10100010.01100001.00000000.00000000162.97.0.0
Subnet mask11111111.11111111.10000000.00000000255.255.128.0
Network10100010.01100001.00000000.00000000162.97.0.0
Broadcast10100010.01100001.01111111.11111111162.97.127.255
Split into smaller subnets/26
/18 (2)/19 (4)/20 (8)/21 (16)/22 (32)/23 (64)/24 (128)/25 (256)/26 (512)/27 (1,024)/28 (2,048)/29 (4,096)

162.97.0.0/17 makes 512 subnets of /26; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1162.97.0.0/26162.97.0.1 to 162.97.0.62162.97.0.6362
2162.97.0.64/26162.97.0.65 to 162.97.0.126162.97.0.12762
3162.97.0.128/26162.97.0.129 to 162.97.0.190162.97.0.19162
4162.97.0.192/26162.97.0.193 to 162.97.0.254162.97.0.25562
5162.97.1.0/26162.97.1.1 to 162.97.1.62162.97.1.6362
6162.97.1.64/26162.97.1.65 to 162.97.1.126162.97.1.12762
7162.97.1.128/26162.97.1.129 to 162.97.1.190162.97.1.19162
8162.97.1.192/26162.97.1.193 to 162.97.1.254162.97.1.25562
9162.97.2.0/26162.97.2.1 to 162.97.2.62162.97.2.6362
10162.97.2.64/26162.97.2.65 to 162.97.2.126162.97.2.12762
11162.97.2.128/26162.97.2.129 to 162.97.2.190162.97.2.19162
12162.97.2.192/26162.97.2.193 to 162.97.2.254162.97.2.25562
13162.97.3.0/26162.97.3.1 to 162.97.3.62162.97.3.6362
14162.97.3.64/26162.97.3.65 to 162.97.3.126162.97.3.12762
15162.97.3.128/26162.97.3.129 to 162.97.3.190162.97.3.19162
16162.97.3.192/26162.97.3.193 to 162.97.3.254162.97.3.25562
17162.97.4.0/26162.97.4.1 to 162.97.4.62162.97.4.6362
18162.97.4.64/26162.97.4.65 to 162.97.4.126162.97.4.12762
19162.97.4.128/26162.97.4.129 to 162.97.4.190162.97.4.19162
20162.97.4.192/26162.97.4.193 to 162.97.4.254162.97.4.25562
21162.97.5.0/26162.97.5.1 to 162.97.5.62162.97.5.6362
22162.97.5.64/26162.97.5.65 to 162.97.5.126162.97.5.12762
23162.97.5.128/26162.97.5.129 to 162.97.5.190162.97.5.19162
24162.97.5.192/26162.97.5.193 to 162.97.5.254162.97.5.25562
25162.97.6.0/26162.97.6.1 to 162.97.6.62162.97.6.6362
26162.97.6.64/26162.97.6.65 to 162.97.6.126162.97.6.12762
27162.97.6.128/26162.97.6.129 to 162.97.6.190162.97.6.19162
28162.97.6.192/26162.97.6.193 to 162.97.6.254162.97.6.25562
29162.97.7.0/26162.97.7.1 to 162.97.7.62162.97.7.6362
30162.97.7.64/26162.97.7.65 to 162.97.7.126162.97.7.12762
31162.97.7.128/26162.97.7.129 to 162.97.7.190162.97.7.19162
32162.97.7.192/26162.97.7.193 to 162.97.7.254162.97.7.25562
33162.97.8.0/26162.97.8.1 to 162.97.8.62162.97.8.6362
34162.97.8.64/26162.97.8.65 to 162.97.8.126162.97.8.12762
35162.97.8.128/26162.97.8.129 to 162.97.8.190162.97.8.19162
36162.97.8.192/26162.97.8.193 to 162.97.8.254162.97.8.25562
37162.97.9.0/26162.97.9.1 to 162.97.9.62162.97.9.6362
38162.97.9.64/26162.97.9.65 to 162.97.9.126162.97.9.12762
39162.97.9.128/26162.97.9.129 to 162.97.9.190162.97.9.19162
40162.97.9.192/26162.97.9.193 to 162.97.9.254162.97.9.25562
41162.97.10.0/26162.97.10.1 to 162.97.10.62162.97.10.6362
42162.97.10.64/26162.97.10.65 to 162.97.10.126162.97.10.12762
43162.97.10.128/26162.97.10.129 to 162.97.10.190162.97.10.19162
44162.97.10.192/26162.97.10.193 to 162.97.10.254162.97.10.25562
45162.97.11.0/26162.97.11.1 to 162.97.11.62162.97.11.6362
46162.97.11.64/26162.97.11.65 to 162.97.11.126162.97.11.12762
47162.97.11.128/26162.97.11.129 to 162.97.11.190162.97.11.19162
48162.97.11.192/26162.97.11.193 to 162.97.11.254162.97.11.25562
49162.97.12.0/26162.97.12.1 to 162.97.12.62162.97.12.6362
50162.97.12.64/26162.97.12.65 to 162.97.12.126162.97.12.12762
51162.97.12.128/26162.97.12.129 to 162.97.12.190162.97.12.19162
52162.97.12.192/26162.97.12.193 to 162.97.12.254162.97.12.25562
53162.97.13.0/26162.97.13.1 to 162.97.13.62162.97.13.6362
54162.97.13.64/26162.97.13.65 to 162.97.13.126162.97.13.12762
55162.97.13.128/26162.97.13.129 to 162.97.13.190162.97.13.19162
56162.97.13.192/26162.97.13.193 to 162.97.13.254162.97.13.25562
57162.97.14.0/26162.97.14.1 to 162.97.14.62162.97.14.6362
58162.97.14.64/26162.97.14.65 to 162.97.14.126162.97.14.12762
59162.97.14.128/26162.97.14.129 to 162.97.14.190162.97.14.19162
60162.97.14.192/26162.97.14.193 to 162.97.14.254162.97.14.25562
61162.97.15.0/26162.97.15.1 to 162.97.15.62162.97.15.6362
62162.97.15.64/26162.97.15.65 to 162.97.15.126162.97.15.12762
63162.97.15.128/26162.97.15.129 to 162.97.15.190162.97.15.19162
64162.97.15.192/26162.97.15.193 to 162.97.15.254162.97.15.25562
65162.97.16.0/26162.97.16.1 to 162.97.16.62162.97.16.6362
66162.97.16.64/26162.97.16.65 to 162.97.16.126162.97.16.12762
67162.97.16.128/26162.97.16.129 to 162.97.16.190162.97.16.19162
68162.97.16.192/26162.97.16.193 to 162.97.16.254162.97.16.25562
69162.97.17.0/26162.97.17.1 to 162.97.17.62162.97.17.6362
70162.97.17.64/26162.97.17.65 to 162.97.17.126162.97.17.12762
71162.97.17.128/26162.97.17.129 to 162.97.17.190162.97.17.19162
72162.97.17.192/26162.97.17.193 to 162.97.17.254162.97.17.25562
73162.97.18.0/26162.97.18.1 to 162.97.18.62162.97.18.6362
74162.97.18.64/26162.97.18.65 to 162.97.18.126162.97.18.12762
75162.97.18.128/26162.97.18.129 to 162.97.18.190162.97.18.19162
76162.97.18.192/26162.97.18.193 to 162.97.18.254162.97.18.25562
77162.97.19.0/26162.97.19.1 to 162.97.19.62162.97.19.6362
78162.97.19.64/26162.97.19.65 to 162.97.19.126162.97.19.12762
79162.97.19.128/26162.97.19.129 to 162.97.19.190162.97.19.19162
80162.97.19.192/26162.97.19.193 to 162.97.19.254162.97.19.25562
81162.97.20.0/26162.97.20.1 to 162.97.20.62162.97.20.6362
82162.97.20.64/26162.97.20.65 to 162.97.20.126162.97.20.12762
83162.97.20.128/26162.97.20.129 to 162.97.20.190162.97.20.19162
84162.97.20.192/26162.97.20.193 to 162.97.20.254162.97.20.25562
85162.97.21.0/26162.97.21.1 to 162.97.21.62162.97.21.6362
86162.97.21.64/26162.97.21.65 to 162.97.21.126162.97.21.12762
87162.97.21.128/26162.97.21.129 to 162.97.21.190162.97.21.19162
88162.97.21.192/26162.97.21.193 to 162.97.21.254162.97.21.25562
89162.97.22.0/26162.97.22.1 to 162.97.22.62162.97.22.6362
90162.97.22.64/26162.97.22.65 to 162.97.22.126162.97.22.12762
91162.97.22.128/26162.97.22.129 to 162.97.22.190162.97.22.19162
92162.97.22.192/26162.97.22.193 to 162.97.22.254162.97.22.25562
93162.97.23.0/26162.97.23.1 to 162.97.23.62162.97.23.6362
94162.97.23.64/26162.97.23.65 to 162.97.23.126162.97.23.12762
95162.97.23.128/26162.97.23.129 to 162.97.23.190162.97.23.19162
96162.97.23.192/26162.97.23.193 to 162.97.23.254162.97.23.25562
97162.97.24.0/26162.97.24.1 to 162.97.24.62162.97.24.6362
98162.97.24.64/26162.97.24.65 to 162.97.24.126162.97.24.12762
99162.97.24.128/26162.97.24.129 to 162.97.24.190162.97.24.19162
100162.97.24.192/26162.97.24.193 to 162.97.24.254162.97.24.25562
101162.97.25.0/26162.97.25.1 to 162.97.25.62162.97.25.6362
102162.97.25.64/26162.97.25.65 to 162.97.25.126162.97.25.12762
103162.97.25.128/26162.97.25.129 to 162.97.25.190162.97.25.19162
104162.97.25.192/26162.97.25.193 to 162.97.25.254162.97.25.25562
105162.97.26.0/26162.97.26.1 to 162.97.26.62162.97.26.6362
106162.97.26.64/26162.97.26.65 to 162.97.26.126162.97.26.12762
107162.97.26.128/26162.97.26.129 to 162.97.26.190162.97.26.19162
108162.97.26.192/26162.97.26.193 to 162.97.26.254162.97.26.25562
109162.97.27.0/26162.97.27.1 to 162.97.27.62162.97.27.6362
110162.97.27.64/26162.97.27.65 to 162.97.27.126162.97.27.12762
111162.97.27.128/26162.97.27.129 to 162.97.27.190162.97.27.19162
112162.97.27.192/26162.97.27.193 to 162.97.27.254162.97.27.25562
113162.97.28.0/26162.97.28.1 to 162.97.28.62162.97.28.6362
114162.97.28.64/26162.97.28.65 to 162.97.28.126162.97.28.12762
115162.97.28.128/26162.97.28.129 to 162.97.28.190162.97.28.19162
116162.97.28.192/26162.97.28.193 to 162.97.28.254162.97.28.25562
117162.97.29.0/26162.97.29.1 to 162.97.29.62162.97.29.6362
118162.97.29.64/26162.97.29.65 to 162.97.29.126162.97.29.12762
119162.97.29.128/26162.97.29.129 to 162.97.29.190162.97.29.19162
120162.97.29.192/26162.97.29.193 to 162.97.29.254162.97.29.25562
121162.97.30.0/26162.97.30.1 to 162.97.30.62162.97.30.6362
122162.97.30.64/26162.97.30.65 to 162.97.30.126162.97.30.12762
123162.97.30.128/26162.97.30.129 to 162.97.30.190162.97.30.19162
124162.97.30.192/26162.97.30.193 to 162.97.30.254162.97.30.25562
125162.97.31.0/26162.97.31.1 to 162.97.31.62162.97.31.6362
126162.97.31.64/26162.97.31.65 to 162.97.31.126162.97.31.12762
127162.97.31.128/26162.97.31.129 to 162.97.31.190162.97.31.19162
128162.97.31.192/26162.97.31.193 to 162.97.31.254162.97.31.25562
129162.97.32.0/26162.97.32.1 to 162.97.32.62162.97.32.6362
130162.97.32.64/26162.97.32.65 to 162.97.32.126162.97.32.12762
131162.97.32.128/26162.97.32.129 to 162.97.32.190162.97.32.19162
132162.97.32.192/26162.97.32.193 to 162.97.32.254162.97.32.25562
133162.97.33.0/26162.97.33.1 to 162.97.33.62162.97.33.6362
134162.97.33.64/26162.97.33.65 to 162.97.33.126162.97.33.12762
135162.97.33.128/26162.97.33.129 to 162.97.33.190162.97.33.19162
136162.97.33.192/26162.97.33.193 to 162.97.33.254162.97.33.25562
137162.97.34.0/26162.97.34.1 to 162.97.34.62162.97.34.6362
138162.97.34.64/26162.97.34.65 to 162.97.34.126162.97.34.12762
139162.97.34.128/26162.97.34.129 to 162.97.34.190162.97.34.19162
140162.97.34.192/26162.97.34.193 to 162.97.34.254162.97.34.25562
141162.97.35.0/26162.97.35.1 to 162.97.35.62162.97.35.6362
142162.97.35.64/26162.97.35.65 to 162.97.35.126162.97.35.12762
143162.97.35.128/26162.97.35.129 to 162.97.35.190162.97.35.19162
144162.97.35.192/26162.97.35.193 to 162.97.35.254162.97.35.25562
145162.97.36.0/26162.97.36.1 to 162.97.36.62162.97.36.6362
146162.97.36.64/26162.97.36.65 to 162.97.36.126162.97.36.12762
147162.97.36.128/26162.97.36.129 to 162.97.36.190162.97.36.19162
148162.97.36.192/26162.97.36.193 to 162.97.36.254162.97.36.25562
149162.97.37.0/26162.97.37.1 to 162.97.37.62162.97.37.6362
150162.97.37.64/26162.97.37.65 to 162.97.37.126162.97.37.12762
151162.97.37.128/26162.97.37.129 to 162.97.37.190162.97.37.19162
152162.97.37.192/26162.97.37.193 to 162.97.37.254162.97.37.25562
153162.97.38.0/26162.97.38.1 to 162.97.38.62162.97.38.6362
154162.97.38.64/26162.97.38.65 to 162.97.38.126162.97.38.12762
155162.97.38.128/26162.97.38.129 to 162.97.38.190162.97.38.19162
156162.97.38.192/26162.97.38.193 to 162.97.38.254162.97.38.25562
157162.97.39.0/26162.97.39.1 to 162.97.39.62162.97.39.6362
158162.97.39.64/26162.97.39.65 to 162.97.39.126162.97.39.12762
159162.97.39.128/26162.97.39.129 to 162.97.39.190162.97.39.19162
160162.97.39.192/26162.97.39.193 to 162.97.39.254162.97.39.25562
161162.97.40.0/26162.97.40.1 to 162.97.40.62162.97.40.6362
162162.97.40.64/26162.97.40.65 to 162.97.40.126162.97.40.12762
163162.97.40.128/26162.97.40.129 to 162.97.40.190162.97.40.19162
164162.97.40.192/26162.97.40.193 to 162.97.40.254162.97.40.25562
165162.97.41.0/26162.97.41.1 to 162.97.41.62162.97.41.6362
166162.97.41.64/26162.97.41.65 to 162.97.41.126162.97.41.12762
167162.97.41.128/26162.97.41.129 to 162.97.41.190162.97.41.19162
168162.97.41.192/26162.97.41.193 to 162.97.41.254162.97.41.25562
169162.97.42.0/26162.97.42.1 to 162.97.42.62162.97.42.6362
170162.97.42.64/26162.97.42.65 to 162.97.42.126162.97.42.12762
171162.97.42.128/26162.97.42.129 to 162.97.42.190162.97.42.19162
172162.97.42.192/26162.97.42.193 to 162.97.42.254162.97.42.25562
173162.97.43.0/26162.97.43.1 to 162.97.43.62162.97.43.6362
174162.97.43.64/26162.97.43.65 to 162.97.43.126162.97.43.12762
175162.97.43.128/26162.97.43.129 to 162.97.43.190162.97.43.19162
176162.97.43.192/26162.97.43.193 to 162.97.43.254162.97.43.25562
177162.97.44.0/26162.97.44.1 to 162.97.44.62162.97.44.6362
178162.97.44.64/26162.97.44.65 to 162.97.44.126162.97.44.12762
179162.97.44.128/26162.97.44.129 to 162.97.44.190162.97.44.19162
180162.97.44.192/26162.97.44.193 to 162.97.44.254162.97.44.25562
181162.97.45.0/26162.97.45.1 to 162.97.45.62162.97.45.6362
182162.97.45.64/26162.97.45.65 to 162.97.45.126162.97.45.12762
183162.97.45.128/26162.97.45.129 to 162.97.45.190162.97.45.19162
184162.97.45.192/26162.97.45.193 to 162.97.45.254162.97.45.25562
185162.97.46.0/26162.97.46.1 to 162.97.46.62162.97.46.6362
186162.97.46.64/26162.97.46.65 to 162.97.46.126162.97.46.12762
187162.97.46.128/26162.97.46.129 to 162.97.46.190162.97.46.19162
188162.97.46.192/26162.97.46.193 to 162.97.46.254162.97.46.25562
189162.97.47.0/26162.97.47.1 to 162.97.47.62162.97.47.6362
190162.97.47.64/26162.97.47.65 to 162.97.47.126162.97.47.12762
191162.97.47.128/26162.97.47.129 to 162.97.47.190162.97.47.19162
192162.97.47.192/26162.97.47.193 to 162.97.47.254162.97.47.25562
193162.97.48.0/26162.97.48.1 to 162.97.48.62162.97.48.6362
194162.97.48.64/26162.97.48.65 to 162.97.48.126162.97.48.12762
195162.97.48.128/26162.97.48.129 to 162.97.48.190162.97.48.19162
196162.97.48.192/26162.97.48.193 to 162.97.48.254162.97.48.25562
197162.97.49.0/26162.97.49.1 to 162.97.49.62162.97.49.6362
198162.97.49.64/26162.97.49.65 to 162.97.49.126162.97.49.12762
199162.97.49.128/26162.97.49.129 to 162.97.49.190162.97.49.19162
200162.97.49.192/26162.97.49.193 to 162.97.49.254162.97.49.25562
201162.97.50.0/26162.97.50.1 to 162.97.50.62162.97.50.6362
202162.97.50.64/26162.97.50.65 to 162.97.50.126162.97.50.12762
203162.97.50.128/26162.97.50.129 to 162.97.50.190162.97.50.19162
204162.97.50.192/26162.97.50.193 to 162.97.50.254162.97.50.25562
205162.97.51.0/26162.97.51.1 to 162.97.51.62162.97.51.6362
206162.97.51.64/26162.97.51.65 to 162.97.51.126162.97.51.12762
207162.97.51.128/26162.97.51.129 to 162.97.51.190162.97.51.19162
208162.97.51.192/26162.97.51.193 to 162.97.51.254162.97.51.25562
209162.97.52.0/26162.97.52.1 to 162.97.52.62162.97.52.6362
210162.97.52.64/26162.97.52.65 to 162.97.52.126162.97.52.12762
211162.97.52.128/26162.97.52.129 to 162.97.52.190162.97.52.19162
212162.97.52.192/26162.97.52.193 to 162.97.52.254162.97.52.25562
213162.97.53.0/26162.97.53.1 to 162.97.53.62162.97.53.6362
214162.97.53.64/26162.97.53.65 to 162.97.53.126162.97.53.12762
215162.97.53.128/26162.97.53.129 to 162.97.53.190162.97.53.19162
216162.97.53.192/26162.97.53.193 to 162.97.53.254162.97.53.25562
217162.97.54.0/26162.97.54.1 to 162.97.54.62162.97.54.6362
218162.97.54.64/26162.97.54.65 to 162.97.54.126162.97.54.12762
219162.97.54.128/26162.97.54.129 to 162.97.54.190162.97.54.19162
220162.97.54.192/26162.97.54.193 to 162.97.54.254162.97.54.25562
221162.97.55.0/26162.97.55.1 to 162.97.55.62162.97.55.6362
222162.97.55.64/26162.97.55.65 to 162.97.55.126162.97.55.12762
223162.97.55.128/26162.97.55.129 to 162.97.55.190162.97.55.19162
224162.97.55.192/26162.97.55.193 to 162.97.55.254162.97.55.25562
225162.97.56.0/26162.97.56.1 to 162.97.56.62162.97.56.6362
226162.97.56.64/26162.97.56.65 to 162.97.56.126162.97.56.12762
227162.97.56.128/26162.97.56.129 to 162.97.56.190162.97.56.19162
228162.97.56.192/26162.97.56.193 to 162.97.56.254162.97.56.25562
229162.97.57.0/26162.97.57.1 to 162.97.57.62162.97.57.6362
230162.97.57.64/26162.97.57.65 to 162.97.57.126162.97.57.12762
231162.97.57.128/26162.97.57.129 to 162.97.57.190162.97.57.19162
232162.97.57.192/26162.97.57.193 to 162.97.57.254162.97.57.25562
233162.97.58.0/26162.97.58.1 to 162.97.58.62162.97.58.6362
234162.97.58.64/26162.97.58.65 to 162.97.58.126162.97.58.12762
235162.97.58.128/26162.97.58.129 to 162.97.58.190162.97.58.19162
236162.97.58.192/26162.97.58.193 to 162.97.58.254162.97.58.25562
237162.97.59.0/26162.97.59.1 to 162.97.59.62162.97.59.6362
238162.97.59.64/26162.97.59.65 to 162.97.59.126162.97.59.12762
239162.97.59.128/26162.97.59.129 to 162.97.59.190162.97.59.19162
240162.97.59.192/26162.97.59.193 to 162.97.59.254162.97.59.25562
241162.97.60.0/26162.97.60.1 to 162.97.60.62162.97.60.6362
242162.97.60.64/26162.97.60.65 to 162.97.60.126162.97.60.12762
243162.97.60.128/26162.97.60.129 to 162.97.60.190162.97.60.19162
244162.97.60.192/26162.97.60.193 to 162.97.60.254162.97.60.25562
245162.97.61.0/26162.97.61.1 to 162.97.61.62162.97.61.6362
246162.97.61.64/26162.97.61.65 to 162.97.61.126162.97.61.12762
247162.97.61.128/26162.97.61.129 to 162.97.61.190162.97.61.19162
248162.97.61.192/26162.97.61.193 to 162.97.61.254162.97.61.25562
249162.97.62.0/26162.97.62.1 to 162.97.62.62162.97.62.6362
250162.97.62.64/26162.97.62.65 to 162.97.62.126162.97.62.12762
251162.97.62.128/26162.97.62.129 to 162.97.62.190162.97.62.19162
252162.97.62.192/26162.97.62.193 to 162.97.62.254162.97.62.25562
253162.97.63.0/26162.97.63.1 to 162.97.63.62162.97.63.6362
254162.97.63.64/26162.97.63.65 to 162.97.63.126162.97.63.12762
255162.97.63.128/26162.97.63.129 to 162.97.63.190162.97.63.19162
256162.97.63.192/26162.97.63.193 to 162.97.63.254162.97.63.25562

IPv4 CIDR reference (/0 to /32)

IPv4 prefix lengths
PrefixSubnet maskWildcardAddressesUsable hostsSizeTypical use
/00.0.0.0255.255.255.2554,294,967,2964,294,967,29416,777,216 × /24
/1128.0.0.0127.255.255.2552,147,483,6482,147,483,6468,388,608 × /24
/2192.0.0.063.255.255.2551,073,741,8241,073,741,8224,194,304 × /24
/3224.0.0.031.255.255.255536,870,912536,870,9102,097,152 × /24
/4240.0.0.015.255.255.255268,435,456268,435,4541,048,576 × /24
/5248.0.0.07.255.255.255134,217,728134,217,726524,288 × /24
/6252.0.0.03.255.255.25567,108,86467,108,862262,144 × /24
/7254.0.0.01.255.255.25533,554,43233,554,430131,072 × /24
/8255.0.0.00.255.255.25516,777,21616,777,21465,536 × /24Old class A; 10.0.0.0/8
/9255.128.0.00.127.255.2558,388,6088,388,60632,768 × /24
/10255.192.0.00.63.255.2554,194,3044,194,30216,384 × /24
/11255.224.0.00.31.255.2552,097,1522,097,1508,192 × /24
/12255.240.0.00.15.255.2551,048,5761,048,5744,096 × /24172.16.0.0/12
/13255.248.0.00.7.255.255524,288524,2862,048 × /24
/14255.252.0.00.3.255.255262,144262,1421,024 × /24
/15255.254.0.00.1.255.255131,072131,070512 × /24
/16255.255.0.00.0.255.25565,53665,534256 × /24Old class B; 192.168.0.0/16
/17255.255.128.00.0.127.25532,76832,766128 × /24
/18255.255.192.00.0.63.25516,38416,38264 × /24
/19255.255.224.00.0.31.2558,1928,19032 × /24
/20255.255.240.00.0.15.2554,0964,09416 × /24
/21255.255.248.00.0.7.2552,0482,0468 × /24
/22255.255.252.00.0.3.2551,0241,0224 × /24Large office or guest Wi-Fi (1,022 hosts)
/23255.255.254.00.0.1.2555125102 × /24Larger office LAN (510 hosts)
/24255.255.255.00.0.0.2552562541 × /24Typical office LAN (old class C)
/25255.255.255.1280.0.0.1271281261/2 of a /24Smaller LAN or VLAN
/26255.255.255.1920.0.0.6364621/4 of a /24Smaller LAN or VLAN
/27255.255.255.2240.0.0.3132301/8 of a /24Small VLAN, phones, cameras
/28255.255.255.2400.0.0.1516141/16 of a /24Small VLAN, phones, cameras
/29255.255.255.2480.0.0.7861/32 of a /24Small fixed public block (5 usable)
/30255.255.255.2520.0.0.3421/64 of a /24Point-to-point (old style)
/31255.255.255.2540.0.0.1221/128 of a /24Point-to-point link (RFC 3021)
/32255.255.255.2550.0.0.0111/256 of a /24One host

IPv6 prefix reference

IPv6 prefix lengths
PrefixAddresses/64 LANs/48 sitesNibbleTypical use
/342,535,295,865,117,307,932,921,825,928,971,026,432 (2^125)2,305,843,009,213,693,95235,184,372,088,832NoAll global unicast (2000::/3)
/165,192,296,858,534,827,628,530,496,329,220,096 (2^112)281,474,976,710,6564,294,967,296Yes
/20324,518,553,658,426,726,783,156,020,576,256 (2^108)17,592,186,044,416268,435,456YesLarge provider allocation (RIPE minimum for some)
/29633,825,300,114,114,700,748,351,602,688 (2^99)34,359,738,368524,288NoRIPE allocation to a provider (often)
/3279,228,162,514,264,337,593,543,950,336 (2^96)4,294,967,29665,536YesProvider allocation (RIPE default)
/364,951,760,157,141,521,099,596,496,896 (2^92)268,435,4564,096Yes
/40309,485,009,821,345,068,724,781,056 (2^88)16,777,216256Yes
/4419,342,813,113,834,066,795,298,816 (2^84)1,048,57616Yes
/481,208,925,819,614,629,174,706,176 (2^80)65,5361YesOne site or organisation (RIPE PI / assignment)
/5275,557,863,725,914,323,419,136 (2^76)4,096Yes
/564,722,366,482,869,645,213,696 (2^72)256YesSmall site or home (common provider assignment)
/60295,147,905,179,352,825,856 (2^68)16YesSome home broadband (16 LANs)
/6418,446,744,073,709,551,616 (2^64)1YesOne LAN or VLAN (needed for SLAAC)
/7272,057,594,037,927,936 (2^56)1/256 of a /64Yes
/80281,474,976,710,656 (2^48)1/65,536 of a /64Yes
/964,294,967,2961/4,294,967,296 of a /64YesEmbeds an IPv4 address (NAT64)
/11265,5361/281,474,976,710,656 of a /64Yes
/1202561/72,057,594,037,927,936 of a /64Yes
/124161/1,152,921,504,606,846,976 of a /64Yes
/12641/4,611,686,018,427,387,904 of a /64No
/12721/9,223,372,036,854,775,808 of a /64NoPoint-to-point link (RFC 6164)
/12811/18,446,744,073,709,551,616 of a /64YesOne host or loopback

Private and special ranges

IPv4

Special-purpose ranges
RangeNameWhat it is
255.255.255.255/32Limited broadcastEvery host on the local network
0.0.0.0/8This networkNot routed; 0.0.0.0 means "any address" in settings
10.0.0.0/8Private (RFC 1918)Office and home networks; not routed on the internet
100.64.0.0/10Shared address space (CGNAT)Used by providers behind carrier-grade NAT (RFC 6598)
127.0.0.0/8LoopbackThis computer
169.254.0.0/16Link-local (APIPA)Self-assigned when no DHCP server answers
172.16.0.0/12Private (RFC 1918)Office and home networks; not routed on the internet
192.0.0.0/24IETF protocol assignmentsSpecial uses such as DS-Lite
192.0.2.0/24Documentation (TEST-NET-1)For examples; never used on a network
192.88.99.0/246to4 relay (deprecated)Formerly anycast for 6to4
192.168.0.0/16Private (RFC 1918)Office and home networks; not routed on the internet
198.18.0.0/15BenchmarkingNetwork equipment testing (RFC 2544)
198.51.100.0/24Documentation (TEST-NET-2)For examples; never used on a network
203.0.113.0/24Documentation (TEST-NET-3)For examples; never used on a network
224.0.0.0/4MulticastOne-to-many traffic, such as IPTV and routing protocols
240.0.0.0/4ReservedFuture use; not usable on most systems

IPv6

Special-purpose ranges
RangeNameWhat it is
::/128UnspecifiedNo address; :: means "any address" in settings
::1/128LoopbackThis computer
::ffff:0:0/96IPv4-mappedAn IPv4 address written as IPv6
64:ff9b::/96NAT64IPv4 addresses reached through a NAT64 gateway
100::/64Discard onlyTraffic sent here is dropped (RFC 6666)
2001:db8::/32DocumentationFor examples; never used on a network
2001::/32TeredoIPv6 tunnelled over IPv4 UDP
2002::/166to4IPv6 tunnelled over IPv4 (largely retired)
3fff::/20DocumentationFor examples (RFC 9637)
fc00::/7Unique local (ULA)Private IPv6, like RFC 1918; usually fd00::/8
fe80::/10Link-localEvery IPv6 interface has one; not routed
ff00::/8MulticastOne-to-many traffic; replaces broadcast
2000::/3Global unicastPublic internet addresses

About this tool

A network is written as an address and a prefix length, such as 192.168.1.0/24: the first 24 bits name the network and the rest number the devices on it. The calculator works out where the network starts and ends, how many devices it holds, its subnet and wildcard masks, and the reverse DNS zone to ask your provider for.

It also splits a network into equal smaller ones (one per VLAN or site), turns a range of addresses into the fewest CIDR blocks for a firewall rule, and lists every IPv4 prefix length and the common IPv6 ones in reference tables.

Common questions

Why are two addresses lost in every IPv4 subnet?

The first address names the network and the last is the broadcast address, so a /24 has 256 addresses but 254 for devices. A /31 (a link between two routers) and a /32 (one host) are the exceptions.

What size of IPv6 network should a LAN use?

Always /64. Devices pick their own address within it (SLAAC), which needs the full 64 bits. A site usually gets a /48 or /56 from its provider, which holds 65,536 or 256 LANs.

What is a wildcard mask?

The subnet mask turned inside out: 255.255.255.0 becomes 0.0.0.255. Cisco access lists and OSPF use it to say which bits must match.

Which ranges can I use inside an office?

IPv4: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. IPv6: unique local addresses from fd00::/8, though most networks use the public prefix from their provider.