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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.

Network167.0.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
167.0.0.0
Broadcast address
167.127.255.255
First usable
167.0.0.1
Last usable
167.127.255.254
Usable hosts
8,388,606 (8,388,608 less the network and broadcast addresses)
Subnet mask
255.128.0.0
Wildcard mask
0.127.255.255 (Cisco ACLs, OSPF)
Prefix length
/9
Type
Public public
Old class
B (default /16)
As numbers
Hex A7000000 · Integer 2801795072 to 2810183679
Reverse DNS zones
0.167.in-addr.arpa
1.167.in-addr.arpa
2.167.in-addr.arpa
3.167.in-addr.arpa
4.167.in-addr.arpa
5.167.in-addr.arpa
6.167.in-addr.arpa
7.167.in-addr.arpa
8.167.in-addr.arpa
9.167.in-addr.arpa
10.167.in-addr.arpa
11.167.in-addr.arpa
12.167.in-addr.arpa
13.167.in-addr.arpa
14.167.in-addr.arpa
15.167.in-addr.arpa
and 112 more
/9 is not on a 8-bit boundary, so it takes 128 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10100111.00000000.00000000.00000000167.0.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network10100111.00000000.00000000.00000000167.0.0.0
Broadcast10100111.01111111.11111111.11111111167.127.255.255
Split into smaller subnets/18
/10 (2)/11 (4)/12 (8)/13 (16)/14 (32)/15 (64)/16 (128)/17 (256)/18 (512)/19 (1,024)/20 (2,048)/21 (4,096)

167.0.0.0/9 makes 512 subnets of /18; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1167.0.0.0/18167.0.0.1 to 167.0.63.254167.0.63.25516,382
2167.0.64.0/18167.0.64.1 to 167.0.127.254167.0.127.25516,382
3167.0.128.0/18167.0.128.1 to 167.0.191.254167.0.191.25516,382
4167.0.192.0/18167.0.192.1 to 167.0.255.254167.0.255.25516,382
5167.1.0.0/18167.1.0.1 to 167.1.63.254167.1.63.25516,382
6167.1.64.0/18167.1.64.1 to 167.1.127.254167.1.127.25516,382
7167.1.128.0/18167.1.128.1 to 167.1.191.254167.1.191.25516,382
8167.1.192.0/18167.1.192.1 to 167.1.255.254167.1.255.25516,382
9167.2.0.0/18167.2.0.1 to 167.2.63.254167.2.63.25516,382
10167.2.64.0/18167.2.64.1 to 167.2.127.254167.2.127.25516,382
11167.2.128.0/18167.2.128.1 to 167.2.191.254167.2.191.25516,382
12167.2.192.0/18167.2.192.1 to 167.2.255.254167.2.255.25516,382
13167.3.0.0/18167.3.0.1 to 167.3.63.254167.3.63.25516,382
14167.3.64.0/18167.3.64.1 to 167.3.127.254167.3.127.25516,382
15167.3.128.0/18167.3.128.1 to 167.3.191.254167.3.191.25516,382
16167.3.192.0/18167.3.192.1 to 167.3.255.254167.3.255.25516,382
17167.4.0.0/18167.4.0.1 to 167.4.63.254167.4.63.25516,382
18167.4.64.0/18167.4.64.1 to 167.4.127.254167.4.127.25516,382
19167.4.128.0/18167.4.128.1 to 167.4.191.254167.4.191.25516,382
20167.4.192.0/18167.4.192.1 to 167.4.255.254167.4.255.25516,382
21167.5.0.0/18167.5.0.1 to 167.5.63.254167.5.63.25516,382
22167.5.64.0/18167.5.64.1 to 167.5.127.254167.5.127.25516,382
23167.5.128.0/18167.5.128.1 to 167.5.191.254167.5.191.25516,382
24167.5.192.0/18167.5.192.1 to 167.5.255.254167.5.255.25516,382
25167.6.0.0/18167.6.0.1 to 167.6.63.254167.6.63.25516,382
26167.6.64.0/18167.6.64.1 to 167.6.127.254167.6.127.25516,382
27167.6.128.0/18167.6.128.1 to 167.6.191.254167.6.191.25516,382
28167.6.192.0/18167.6.192.1 to 167.6.255.254167.6.255.25516,382
29167.7.0.0/18167.7.0.1 to 167.7.63.254167.7.63.25516,382
30167.7.64.0/18167.7.64.1 to 167.7.127.254167.7.127.25516,382
31167.7.128.0/18167.7.128.1 to 167.7.191.254167.7.191.25516,382
32167.7.192.0/18167.7.192.1 to 167.7.255.254167.7.255.25516,382
33167.8.0.0/18167.8.0.1 to 167.8.63.254167.8.63.25516,382
34167.8.64.0/18167.8.64.1 to 167.8.127.254167.8.127.25516,382
35167.8.128.0/18167.8.128.1 to 167.8.191.254167.8.191.25516,382
36167.8.192.0/18167.8.192.1 to 167.8.255.254167.8.255.25516,382
37167.9.0.0/18167.9.0.1 to 167.9.63.254167.9.63.25516,382
38167.9.64.0/18167.9.64.1 to 167.9.127.254167.9.127.25516,382
39167.9.128.0/18167.9.128.1 to 167.9.191.254167.9.191.25516,382
40167.9.192.0/18167.9.192.1 to 167.9.255.254167.9.255.25516,382
41167.10.0.0/18167.10.0.1 to 167.10.63.254167.10.63.25516,382
42167.10.64.0/18167.10.64.1 to 167.10.127.254167.10.127.25516,382
43167.10.128.0/18167.10.128.1 to 167.10.191.254167.10.191.25516,382
44167.10.192.0/18167.10.192.1 to 167.10.255.254167.10.255.25516,382
45167.11.0.0/18167.11.0.1 to 167.11.63.254167.11.63.25516,382
46167.11.64.0/18167.11.64.1 to 167.11.127.254167.11.127.25516,382
47167.11.128.0/18167.11.128.1 to 167.11.191.254167.11.191.25516,382
48167.11.192.0/18167.11.192.1 to 167.11.255.254167.11.255.25516,382
49167.12.0.0/18167.12.0.1 to 167.12.63.254167.12.63.25516,382
50167.12.64.0/18167.12.64.1 to 167.12.127.254167.12.127.25516,382
51167.12.128.0/18167.12.128.1 to 167.12.191.254167.12.191.25516,382
52167.12.192.0/18167.12.192.1 to 167.12.255.254167.12.255.25516,382
53167.13.0.0/18167.13.0.1 to 167.13.63.254167.13.63.25516,382
54167.13.64.0/18167.13.64.1 to 167.13.127.254167.13.127.25516,382
55167.13.128.0/18167.13.128.1 to 167.13.191.254167.13.191.25516,382
56167.13.192.0/18167.13.192.1 to 167.13.255.254167.13.255.25516,382
57167.14.0.0/18167.14.0.1 to 167.14.63.254167.14.63.25516,382
58167.14.64.0/18167.14.64.1 to 167.14.127.254167.14.127.25516,382
59167.14.128.0/18167.14.128.1 to 167.14.191.254167.14.191.25516,382
60167.14.192.0/18167.14.192.1 to 167.14.255.254167.14.255.25516,382
61167.15.0.0/18167.15.0.1 to 167.15.63.254167.15.63.25516,382
62167.15.64.0/18167.15.64.1 to 167.15.127.254167.15.127.25516,382
63167.15.128.0/18167.15.128.1 to 167.15.191.254167.15.191.25516,382
64167.15.192.0/18167.15.192.1 to 167.15.255.254167.15.255.25516,382
65167.16.0.0/18167.16.0.1 to 167.16.63.254167.16.63.25516,382
66167.16.64.0/18167.16.64.1 to 167.16.127.254167.16.127.25516,382
67167.16.128.0/18167.16.128.1 to 167.16.191.254167.16.191.25516,382
68167.16.192.0/18167.16.192.1 to 167.16.255.254167.16.255.25516,382
69167.17.0.0/18167.17.0.1 to 167.17.63.254167.17.63.25516,382
70167.17.64.0/18167.17.64.1 to 167.17.127.254167.17.127.25516,382
71167.17.128.0/18167.17.128.1 to 167.17.191.254167.17.191.25516,382
72167.17.192.0/18167.17.192.1 to 167.17.255.254167.17.255.25516,382
73167.18.0.0/18167.18.0.1 to 167.18.63.254167.18.63.25516,382
74167.18.64.0/18167.18.64.1 to 167.18.127.254167.18.127.25516,382
75167.18.128.0/18167.18.128.1 to 167.18.191.254167.18.191.25516,382
76167.18.192.0/18167.18.192.1 to 167.18.255.254167.18.255.25516,382
77167.19.0.0/18167.19.0.1 to 167.19.63.254167.19.63.25516,382
78167.19.64.0/18167.19.64.1 to 167.19.127.254167.19.127.25516,382
79167.19.128.0/18167.19.128.1 to 167.19.191.254167.19.191.25516,382
80167.19.192.0/18167.19.192.1 to 167.19.255.254167.19.255.25516,382
81167.20.0.0/18167.20.0.1 to 167.20.63.254167.20.63.25516,382
82167.20.64.0/18167.20.64.1 to 167.20.127.254167.20.127.25516,382
83167.20.128.0/18167.20.128.1 to 167.20.191.254167.20.191.25516,382
84167.20.192.0/18167.20.192.1 to 167.20.255.254167.20.255.25516,382
85167.21.0.0/18167.21.0.1 to 167.21.63.254167.21.63.25516,382
86167.21.64.0/18167.21.64.1 to 167.21.127.254167.21.127.25516,382
87167.21.128.0/18167.21.128.1 to 167.21.191.254167.21.191.25516,382
88167.21.192.0/18167.21.192.1 to 167.21.255.254167.21.255.25516,382
89167.22.0.0/18167.22.0.1 to 167.22.63.254167.22.63.25516,382
90167.22.64.0/18167.22.64.1 to 167.22.127.254167.22.127.25516,382
91167.22.128.0/18167.22.128.1 to 167.22.191.254167.22.191.25516,382
92167.22.192.0/18167.22.192.1 to 167.22.255.254167.22.255.25516,382
93167.23.0.0/18167.23.0.1 to 167.23.63.254167.23.63.25516,382
94167.23.64.0/18167.23.64.1 to 167.23.127.254167.23.127.25516,382
95167.23.128.0/18167.23.128.1 to 167.23.191.254167.23.191.25516,382
96167.23.192.0/18167.23.192.1 to 167.23.255.254167.23.255.25516,382
97167.24.0.0/18167.24.0.1 to 167.24.63.254167.24.63.25516,382
98167.24.64.0/18167.24.64.1 to 167.24.127.254167.24.127.25516,382
99167.24.128.0/18167.24.128.1 to 167.24.191.254167.24.191.25516,382
100167.24.192.0/18167.24.192.1 to 167.24.255.254167.24.255.25516,382
101167.25.0.0/18167.25.0.1 to 167.25.63.254167.25.63.25516,382
102167.25.64.0/18167.25.64.1 to 167.25.127.254167.25.127.25516,382
103167.25.128.0/18167.25.128.1 to 167.25.191.254167.25.191.25516,382
104167.25.192.0/18167.25.192.1 to 167.25.255.254167.25.255.25516,382
105167.26.0.0/18167.26.0.1 to 167.26.63.254167.26.63.25516,382
106167.26.64.0/18167.26.64.1 to 167.26.127.254167.26.127.25516,382
107167.26.128.0/18167.26.128.1 to 167.26.191.254167.26.191.25516,382
108167.26.192.0/18167.26.192.1 to 167.26.255.254167.26.255.25516,382
109167.27.0.0/18167.27.0.1 to 167.27.63.254167.27.63.25516,382
110167.27.64.0/18167.27.64.1 to 167.27.127.254167.27.127.25516,382
111167.27.128.0/18167.27.128.1 to 167.27.191.254167.27.191.25516,382
112167.27.192.0/18167.27.192.1 to 167.27.255.254167.27.255.25516,382
113167.28.0.0/18167.28.0.1 to 167.28.63.254167.28.63.25516,382
114167.28.64.0/18167.28.64.1 to 167.28.127.254167.28.127.25516,382
115167.28.128.0/18167.28.128.1 to 167.28.191.254167.28.191.25516,382
116167.28.192.0/18167.28.192.1 to 167.28.255.254167.28.255.25516,382
117167.29.0.0/18167.29.0.1 to 167.29.63.254167.29.63.25516,382
118167.29.64.0/18167.29.64.1 to 167.29.127.254167.29.127.25516,382
119167.29.128.0/18167.29.128.1 to 167.29.191.254167.29.191.25516,382
120167.29.192.0/18167.29.192.1 to 167.29.255.254167.29.255.25516,382
121167.30.0.0/18167.30.0.1 to 167.30.63.254167.30.63.25516,382
122167.30.64.0/18167.30.64.1 to 167.30.127.254167.30.127.25516,382
123167.30.128.0/18167.30.128.1 to 167.30.191.254167.30.191.25516,382
124167.30.192.0/18167.30.192.1 to 167.30.255.254167.30.255.25516,382
125167.31.0.0/18167.31.0.1 to 167.31.63.254167.31.63.25516,382
126167.31.64.0/18167.31.64.1 to 167.31.127.254167.31.127.25516,382
127167.31.128.0/18167.31.128.1 to 167.31.191.254167.31.191.25516,382
128167.31.192.0/18167.31.192.1 to 167.31.255.254167.31.255.25516,382
129167.32.0.0/18167.32.0.1 to 167.32.63.254167.32.63.25516,382
130167.32.64.0/18167.32.64.1 to 167.32.127.254167.32.127.25516,382
131167.32.128.0/18167.32.128.1 to 167.32.191.254167.32.191.25516,382
132167.32.192.0/18167.32.192.1 to 167.32.255.254167.32.255.25516,382
133167.33.0.0/18167.33.0.1 to 167.33.63.254167.33.63.25516,382
134167.33.64.0/18167.33.64.1 to 167.33.127.254167.33.127.25516,382
135167.33.128.0/18167.33.128.1 to 167.33.191.254167.33.191.25516,382
136167.33.192.0/18167.33.192.1 to 167.33.255.254167.33.255.25516,382
137167.34.0.0/18167.34.0.1 to 167.34.63.254167.34.63.25516,382
138167.34.64.0/18167.34.64.1 to 167.34.127.254167.34.127.25516,382
139167.34.128.0/18167.34.128.1 to 167.34.191.254167.34.191.25516,382
140167.34.192.0/18167.34.192.1 to 167.34.255.254167.34.255.25516,382
141167.35.0.0/18167.35.0.1 to 167.35.63.254167.35.63.25516,382
142167.35.64.0/18167.35.64.1 to 167.35.127.254167.35.127.25516,382
143167.35.128.0/18167.35.128.1 to 167.35.191.254167.35.191.25516,382
144167.35.192.0/18167.35.192.1 to 167.35.255.254167.35.255.25516,382
145167.36.0.0/18167.36.0.1 to 167.36.63.254167.36.63.25516,382
146167.36.64.0/18167.36.64.1 to 167.36.127.254167.36.127.25516,382
147167.36.128.0/18167.36.128.1 to 167.36.191.254167.36.191.25516,382
148167.36.192.0/18167.36.192.1 to 167.36.255.254167.36.255.25516,382
149167.37.0.0/18167.37.0.1 to 167.37.63.254167.37.63.25516,382
150167.37.64.0/18167.37.64.1 to 167.37.127.254167.37.127.25516,382
151167.37.128.0/18167.37.128.1 to 167.37.191.254167.37.191.25516,382
152167.37.192.0/18167.37.192.1 to 167.37.255.254167.37.255.25516,382
153167.38.0.0/18167.38.0.1 to 167.38.63.254167.38.63.25516,382
154167.38.64.0/18167.38.64.1 to 167.38.127.254167.38.127.25516,382
155167.38.128.0/18167.38.128.1 to 167.38.191.254167.38.191.25516,382
156167.38.192.0/18167.38.192.1 to 167.38.255.254167.38.255.25516,382
157167.39.0.0/18167.39.0.1 to 167.39.63.254167.39.63.25516,382
158167.39.64.0/18167.39.64.1 to 167.39.127.254167.39.127.25516,382
159167.39.128.0/18167.39.128.1 to 167.39.191.254167.39.191.25516,382
160167.39.192.0/18167.39.192.1 to 167.39.255.254167.39.255.25516,382
161167.40.0.0/18167.40.0.1 to 167.40.63.254167.40.63.25516,382
162167.40.64.0/18167.40.64.1 to 167.40.127.254167.40.127.25516,382
163167.40.128.0/18167.40.128.1 to 167.40.191.254167.40.191.25516,382
164167.40.192.0/18167.40.192.1 to 167.40.255.254167.40.255.25516,382
165167.41.0.0/18167.41.0.1 to 167.41.63.254167.41.63.25516,382
166167.41.64.0/18167.41.64.1 to 167.41.127.254167.41.127.25516,382
167167.41.128.0/18167.41.128.1 to 167.41.191.254167.41.191.25516,382
168167.41.192.0/18167.41.192.1 to 167.41.255.254167.41.255.25516,382
169167.42.0.0/18167.42.0.1 to 167.42.63.254167.42.63.25516,382
170167.42.64.0/18167.42.64.1 to 167.42.127.254167.42.127.25516,382
171167.42.128.0/18167.42.128.1 to 167.42.191.254167.42.191.25516,382
172167.42.192.0/18167.42.192.1 to 167.42.255.254167.42.255.25516,382
173167.43.0.0/18167.43.0.1 to 167.43.63.254167.43.63.25516,382
174167.43.64.0/18167.43.64.1 to 167.43.127.254167.43.127.25516,382
175167.43.128.0/18167.43.128.1 to 167.43.191.254167.43.191.25516,382
176167.43.192.0/18167.43.192.1 to 167.43.255.254167.43.255.25516,382
177167.44.0.0/18167.44.0.1 to 167.44.63.254167.44.63.25516,382
178167.44.64.0/18167.44.64.1 to 167.44.127.254167.44.127.25516,382
179167.44.128.0/18167.44.128.1 to 167.44.191.254167.44.191.25516,382
180167.44.192.0/18167.44.192.1 to 167.44.255.254167.44.255.25516,382
181167.45.0.0/18167.45.0.1 to 167.45.63.254167.45.63.25516,382
182167.45.64.0/18167.45.64.1 to 167.45.127.254167.45.127.25516,382
183167.45.128.0/18167.45.128.1 to 167.45.191.254167.45.191.25516,382
184167.45.192.0/18167.45.192.1 to 167.45.255.254167.45.255.25516,382
185167.46.0.0/18167.46.0.1 to 167.46.63.254167.46.63.25516,382
186167.46.64.0/18167.46.64.1 to 167.46.127.254167.46.127.25516,382
187167.46.128.0/18167.46.128.1 to 167.46.191.254167.46.191.25516,382
188167.46.192.0/18167.46.192.1 to 167.46.255.254167.46.255.25516,382
189167.47.0.0/18167.47.0.1 to 167.47.63.254167.47.63.25516,382
190167.47.64.0/18167.47.64.1 to 167.47.127.254167.47.127.25516,382
191167.47.128.0/18167.47.128.1 to 167.47.191.254167.47.191.25516,382
192167.47.192.0/18167.47.192.1 to 167.47.255.254167.47.255.25516,382
193167.48.0.0/18167.48.0.1 to 167.48.63.254167.48.63.25516,382
194167.48.64.0/18167.48.64.1 to 167.48.127.254167.48.127.25516,382
195167.48.128.0/18167.48.128.1 to 167.48.191.254167.48.191.25516,382
196167.48.192.0/18167.48.192.1 to 167.48.255.254167.48.255.25516,382
197167.49.0.0/18167.49.0.1 to 167.49.63.254167.49.63.25516,382
198167.49.64.0/18167.49.64.1 to 167.49.127.254167.49.127.25516,382
199167.49.128.0/18167.49.128.1 to 167.49.191.254167.49.191.25516,382
200167.49.192.0/18167.49.192.1 to 167.49.255.254167.49.255.25516,382
201167.50.0.0/18167.50.0.1 to 167.50.63.254167.50.63.25516,382
202167.50.64.0/18167.50.64.1 to 167.50.127.254167.50.127.25516,382
203167.50.128.0/18167.50.128.1 to 167.50.191.254167.50.191.25516,382
204167.50.192.0/18167.50.192.1 to 167.50.255.254167.50.255.25516,382
205167.51.0.0/18167.51.0.1 to 167.51.63.254167.51.63.25516,382
206167.51.64.0/18167.51.64.1 to 167.51.127.254167.51.127.25516,382
207167.51.128.0/18167.51.128.1 to 167.51.191.254167.51.191.25516,382
208167.51.192.0/18167.51.192.1 to 167.51.255.254167.51.255.25516,382
209167.52.0.0/18167.52.0.1 to 167.52.63.254167.52.63.25516,382
210167.52.64.0/18167.52.64.1 to 167.52.127.254167.52.127.25516,382
211167.52.128.0/18167.52.128.1 to 167.52.191.254167.52.191.25516,382
212167.52.192.0/18167.52.192.1 to 167.52.255.254167.52.255.25516,382
213167.53.0.0/18167.53.0.1 to 167.53.63.254167.53.63.25516,382
214167.53.64.0/18167.53.64.1 to 167.53.127.254167.53.127.25516,382
215167.53.128.0/18167.53.128.1 to 167.53.191.254167.53.191.25516,382
216167.53.192.0/18167.53.192.1 to 167.53.255.254167.53.255.25516,382
217167.54.0.0/18167.54.0.1 to 167.54.63.254167.54.63.25516,382
218167.54.64.0/18167.54.64.1 to 167.54.127.254167.54.127.25516,382
219167.54.128.0/18167.54.128.1 to 167.54.191.254167.54.191.25516,382
220167.54.192.0/18167.54.192.1 to 167.54.255.254167.54.255.25516,382
221167.55.0.0/18167.55.0.1 to 167.55.63.254167.55.63.25516,382
222167.55.64.0/18167.55.64.1 to 167.55.127.254167.55.127.25516,382
223167.55.128.0/18167.55.128.1 to 167.55.191.254167.55.191.25516,382
224167.55.192.0/18167.55.192.1 to 167.55.255.254167.55.255.25516,382
225167.56.0.0/18167.56.0.1 to 167.56.63.254167.56.63.25516,382
226167.56.64.0/18167.56.64.1 to 167.56.127.254167.56.127.25516,382
227167.56.128.0/18167.56.128.1 to 167.56.191.254167.56.191.25516,382
228167.56.192.0/18167.56.192.1 to 167.56.255.254167.56.255.25516,382
229167.57.0.0/18167.57.0.1 to 167.57.63.254167.57.63.25516,382
230167.57.64.0/18167.57.64.1 to 167.57.127.254167.57.127.25516,382
231167.57.128.0/18167.57.128.1 to 167.57.191.254167.57.191.25516,382
232167.57.192.0/18167.57.192.1 to 167.57.255.254167.57.255.25516,382
233167.58.0.0/18167.58.0.1 to 167.58.63.254167.58.63.25516,382
234167.58.64.0/18167.58.64.1 to 167.58.127.254167.58.127.25516,382
235167.58.128.0/18167.58.128.1 to 167.58.191.254167.58.191.25516,382
236167.58.192.0/18167.58.192.1 to 167.58.255.254167.58.255.25516,382
237167.59.0.0/18167.59.0.1 to 167.59.63.254167.59.63.25516,382
238167.59.64.0/18167.59.64.1 to 167.59.127.254167.59.127.25516,382
239167.59.128.0/18167.59.128.1 to 167.59.191.254167.59.191.25516,382
240167.59.192.0/18167.59.192.1 to 167.59.255.254167.59.255.25516,382
241167.60.0.0/18167.60.0.1 to 167.60.63.254167.60.63.25516,382
242167.60.64.0/18167.60.64.1 to 167.60.127.254167.60.127.25516,382
243167.60.128.0/18167.60.128.1 to 167.60.191.254167.60.191.25516,382
244167.60.192.0/18167.60.192.1 to 167.60.255.254167.60.255.25516,382
245167.61.0.0/18167.61.0.1 to 167.61.63.254167.61.63.25516,382
246167.61.64.0/18167.61.64.1 to 167.61.127.254167.61.127.25516,382
247167.61.128.0/18167.61.128.1 to 167.61.191.254167.61.191.25516,382
248167.61.192.0/18167.61.192.1 to 167.61.255.254167.61.255.25516,382
249167.62.0.0/18167.62.0.1 to 167.62.63.254167.62.63.25516,382
250167.62.64.0/18167.62.64.1 to 167.62.127.254167.62.127.25516,382
251167.62.128.0/18167.62.128.1 to 167.62.191.254167.62.191.25516,382
252167.62.192.0/18167.62.192.1 to 167.62.255.254167.62.255.25516,382
253167.63.0.0/18167.63.0.1 to 167.63.63.254167.63.63.25516,382
254167.63.64.0/18167.63.64.1 to 167.63.127.254167.63.127.25516,382
255167.63.128.0/18167.63.128.1 to 167.63.191.254167.63.191.25516,382
256167.63.192.0/18167.63.192.1 to 167.63.255.254167.63.255.25516,382

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.