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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/21
/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 4,096 subnets of /21; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1167.0.0.0/21167.0.0.1 to 167.0.7.254167.0.7.2552,046
2167.0.8.0/21167.0.8.1 to 167.0.15.254167.0.15.2552,046
3167.0.16.0/21167.0.16.1 to 167.0.23.254167.0.23.2552,046
4167.0.24.0/21167.0.24.1 to 167.0.31.254167.0.31.2552,046
5167.0.32.0/21167.0.32.1 to 167.0.39.254167.0.39.2552,046
6167.0.40.0/21167.0.40.1 to 167.0.47.254167.0.47.2552,046
7167.0.48.0/21167.0.48.1 to 167.0.55.254167.0.55.2552,046
8167.0.56.0/21167.0.56.1 to 167.0.63.254167.0.63.2552,046
9167.0.64.0/21167.0.64.1 to 167.0.71.254167.0.71.2552,046
10167.0.72.0/21167.0.72.1 to 167.0.79.254167.0.79.2552,046
11167.0.80.0/21167.0.80.1 to 167.0.87.254167.0.87.2552,046
12167.0.88.0/21167.0.88.1 to 167.0.95.254167.0.95.2552,046
13167.0.96.0/21167.0.96.1 to 167.0.103.254167.0.103.2552,046
14167.0.104.0/21167.0.104.1 to 167.0.111.254167.0.111.2552,046
15167.0.112.0/21167.0.112.1 to 167.0.119.254167.0.119.2552,046
16167.0.120.0/21167.0.120.1 to 167.0.127.254167.0.127.2552,046
17167.0.128.0/21167.0.128.1 to 167.0.135.254167.0.135.2552,046
18167.0.136.0/21167.0.136.1 to 167.0.143.254167.0.143.2552,046
19167.0.144.0/21167.0.144.1 to 167.0.151.254167.0.151.2552,046
20167.0.152.0/21167.0.152.1 to 167.0.159.254167.0.159.2552,046
21167.0.160.0/21167.0.160.1 to 167.0.167.254167.0.167.2552,046
22167.0.168.0/21167.0.168.1 to 167.0.175.254167.0.175.2552,046
23167.0.176.0/21167.0.176.1 to 167.0.183.254167.0.183.2552,046
24167.0.184.0/21167.0.184.1 to 167.0.191.254167.0.191.2552,046
25167.0.192.0/21167.0.192.1 to 167.0.199.254167.0.199.2552,046
26167.0.200.0/21167.0.200.1 to 167.0.207.254167.0.207.2552,046
27167.0.208.0/21167.0.208.1 to 167.0.215.254167.0.215.2552,046
28167.0.216.0/21167.0.216.1 to 167.0.223.254167.0.223.2552,046
29167.0.224.0/21167.0.224.1 to 167.0.231.254167.0.231.2552,046
30167.0.232.0/21167.0.232.1 to 167.0.239.254167.0.239.2552,046
31167.0.240.0/21167.0.240.1 to 167.0.247.254167.0.247.2552,046
32167.0.248.0/21167.0.248.1 to 167.0.255.254167.0.255.2552,046
33167.1.0.0/21167.1.0.1 to 167.1.7.254167.1.7.2552,046
34167.1.8.0/21167.1.8.1 to 167.1.15.254167.1.15.2552,046
35167.1.16.0/21167.1.16.1 to 167.1.23.254167.1.23.2552,046
36167.1.24.0/21167.1.24.1 to 167.1.31.254167.1.31.2552,046
37167.1.32.0/21167.1.32.1 to 167.1.39.254167.1.39.2552,046
38167.1.40.0/21167.1.40.1 to 167.1.47.254167.1.47.2552,046
39167.1.48.0/21167.1.48.1 to 167.1.55.254167.1.55.2552,046
40167.1.56.0/21167.1.56.1 to 167.1.63.254167.1.63.2552,046
41167.1.64.0/21167.1.64.1 to 167.1.71.254167.1.71.2552,046
42167.1.72.0/21167.1.72.1 to 167.1.79.254167.1.79.2552,046
43167.1.80.0/21167.1.80.1 to 167.1.87.254167.1.87.2552,046
44167.1.88.0/21167.1.88.1 to 167.1.95.254167.1.95.2552,046
45167.1.96.0/21167.1.96.1 to 167.1.103.254167.1.103.2552,046
46167.1.104.0/21167.1.104.1 to 167.1.111.254167.1.111.2552,046
47167.1.112.0/21167.1.112.1 to 167.1.119.254167.1.119.2552,046
48167.1.120.0/21167.1.120.1 to 167.1.127.254167.1.127.2552,046
49167.1.128.0/21167.1.128.1 to 167.1.135.254167.1.135.2552,046
50167.1.136.0/21167.1.136.1 to 167.1.143.254167.1.143.2552,046
51167.1.144.0/21167.1.144.1 to 167.1.151.254167.1.151.2552,046
52167.1.152.0/21167.1.152.1 to 167.1.159.254167.1.159.2552,046
53167.1.160.0/21167.1.160.1 to 167.1.167.254167.1.167.2552,046
54167.1.168.0/21167.1.168.1 to 167.1.175.254167.1.175.2552,046
55167.1.176.0/21167.1.176.1 to 167.1.183.254167.1.183.2552,046
56167.1.184.0/21167.1.184.1 to 167.1.191.254167.1.191.2552,046
57167.1.192.0/21167.1.192.1 to 167.1.199.254167.1.199.2552,046
58167.1.200.0/21167.1.200.1 to 167.1.207.254167.1.207.2552,046
59167.1.208.0/21167.1.208.1 to 167.1.215.254167.1.215.2552,046
60167.1.216.0/21167.1.216.1 to 167.1.223.254167.1.223.2552,046
61167.1.224.0/21167.1.224.1 to 167.1.231.254167.1.231.2552,046
62167.1.232.0/21167.1.232.1 to 167.1.239.254167.1.239.2552,046
63167.1.240.0/21167.1.240.1 to 167.1.247.254167.1.247.2552,046
64167.1.248.0/21167.1.248.1 to 167.1.255.254167.1.255.2552,046
65167.2.0.0/21167.2.0.1 to 167.2.7.254167.2.7.2552,046
66167.2.8.0/21167.2.8.1 to 167.2.15.254167.2.15.2552,046
67167.2.16.0/21167.2.16.1 to 167.2.23.254167.2.23.2552,046
68167.2.24.0/21167.2.24.1 to 167.2.31.254167.2.31.2552,046
69167.2.32.0/21167.2.32.1 to 167.2.39.254167.2.39.2552,046
70167.2.40.0/21167.2.40.1 to 167.2.47.254167.2.47.2552,046
71167.2.48.0/21167.2.48.1 to 167.2.55.254167.2.55.2552,046
72167.2.56.0/21167.2.56.1 to 167.2.63.254167.2.63.2552,046
73167.2.64.0/21167.2.64.1 to 167.2.71.254167.2.71.2552,046
74167.2.72.0/21167.2.72.1 to 167.2.79.254167.2.79.2552,046
75167.2.80.0/21167.2.80.1 to 167.2.87.254167.2.87.2552,046
76167.2.88.0/21167.2.88.1 to 167.2.95.254167.2.95.2552,046
77167.2.96.0/21167.2.96.1 to 167.2.103.254167.2.103.2552,046
78167.2.104.0/21167.2.104.1 to 167.2.111.254167.2.111.2552,046
79167.2.112.0/21167.2.112.1 to 167.2.119.254167.2.119.2552,046
80167.2.120.0/21167.2.120.1 to 167.2.127.254167.2.127.2552,046
81167.2.128.0/21167.2.128.1 to 167.2.135.254167.2.135.2552,046
82167.2.136.0/21167.2.136.1 to 167.2.143.254167.2.143.2552,046
83167.2.144.0/21167.2.144.1 to 167.2.151.254167.2.151.2552,046
84167.2.152.0/21167.2.152.1 to 167.2.159.254167.2.159.2552,046
85167.2.160.0/21167.2.160.1 to 167.2.167.254167.2.167.2552,046
86167.2.168.0/21167.2.168.1 to 167.2.175.254167.2.175.2552,046
87167.2.176.0/21167.2.176.1 to 167.2.183.254167.2.183.2552,046
88167.2.184.0/21167.2.184.1 to 167.2.191.254167.2.191.2552,046
89167.2.192.0/21167.2.192.1 to 167.2.199.254167.2.199.2552,046
90167.2.200.0/21167.2.200.1 to 167.2.207.254167.2.207.2552,046
91167.2.208.0/21167.2.208.1 to 167.2.215.254167.2.215.2552,046
92167.2.216.0/21167.2.216.1 to 167.2.223.254167.2.223.2552,046
93167.2.224.0/21167.2.224.1 to 167.2.231.254167.2.231.2552,046
94167.2.232.0/21167.2.232.1 to 167.2.239.254167.2.239.2552,046
95167.2.240.0/21167.2.240.1 to 167.2.247.254167.2.247.2552,046
96167.2.248.0/21167.2.248.1 to 167.2.255.254167.2.255.2552,046
97167.3.0.0/21167.3.0.1 to 167.3.7.254167.3.7.2552,046
98167.3.8.0/21167.3.8.1 to 167.3.15.254167.3.15.2552,046
99167.3.16.0/21167.3.16.1 to 167.3.23.254167.3.23.2552,046
100167.3.24.0/21167.3.24.1 to 167.3.31.254167.3.31.2552,046
101167.3.32.0/21167.3.32.1 to 167.3.39.254167.3.39.2552,046
102167.3.40.0/21167.3.40.1 to 167.3.47.254167.3.47.2552,046
103167.3.48.0/21167.3.48.1 to 167.3.55.254167.3.55.2552,046
104167.3.56.0/21167.3.56.1 to 167.3.63.254167.3.63.2552,046
105167.3.64.0/21167.3.64.1 to 167.3.71.254167.3.71.2552,046
106167.3.72.0/21167.3.72.1 to 167.3.79.254167.3.79.2552,046
107167.3.80.0/21167.3.80.1 to 167.3.87.254167.3.87.2552,046
108167.3.88.0/21167.3.88.1 to 167.3.95.254167.3.95.2552,046
109167.3.96.0/21167.3.96.1 to 167.3.103.254167.3.103.2552,046
110167.3.104.0/21167.3.104.1 to 167.3.111.254167.3.111.2552,046
111167.3.112.0/21167.3.112.1 to 167.3.119.254167.3.119.2552,046
112167.3.120.0/21167.3.120.1 to 167.3.127.254167.3.127.2552,046
113167.3.128.0/21167.3.128.1 to 167.3.135.254167.3.135.2552,046
114167.3.136.0/21167.3.136.1 to 167.3.143.254167.3.143.2552,046
115167.3.144.0/21167.3.144.1 to 167.3.151.254167.3.151.2552,046
116167.3.152.0/21167.3.152.1 to 167.3.159.254167.3.159.2552,046
117167.3.160.0/21167.3.160.1 to 167.3.167.254167.3.167.2552,046
118167.3.168.0/21167.3.168.1 to 167.3.175.254167.3.175.2552,046
119167.3.176.0/21167.3.176.1 to 167.3.183.254167.3.183.2552,046
120167.3.184.0/21167.3.184.1 to 167.3.191.254167.3.191.2552,046
121167.3.192.0/21167.3.192.1 to 167.3.199.254167.3.199.2552,046
122167.3.200.0/21167.3.200.1 to 167.3.207.254167.3.207.2552,046
123167.3.208.0/21167.3.208.1 to 167.3.215.254167.3.215.2552,046
124167.3.216.0/21167.3.216.1 to 167.3.223.254167.3.223.2552,046
125167.3.224.0/21167.3.224.1 to 167.3.231.254167.3.231.2552,046
126167.3.232.0/21167.3.232.1 to 167.3.239.254167.3.239.2552,046
127167.3.240.0/21167.3.240.1 to 167.3.247.254167.3.247.2552,046
128167.3.248.0/21167.3.248.1 to 167.3.255.254167.3.255.2552,046
129167.4.0.0/21167.4.0.1 to 167.4.7.254167.4.7.2552,046
130167.4.8.0/21167.4.8.1 to 167.4.15.254167.4.15.2552,046
131167.4.16.0/21167.4.16.1 to 167.4.23.254167.4.23.2552,046
132167.4.24.0/21167.4.24.1 to 167.4.31.254167.4.31.2552,046
133167.4.32.0/21167.4.32.1 to 167.4.39.254167.4.39.2552,046
134167.4.40.0/21167.4.40.1 to 167.4.47.254167.4.47.2552,046
135167.4.48.0/21167.4.48.1 to 167.4.55.254167.4.55.2552,046
136167.4.56.0/21167.4.56.1 to 167.4.63.254167.4.63.2552,046
137167.4.64.0/21167.4.64.1 to 167.4.71.254167.4.71.2552,046
138167.4.72.0/21167.4.72.1 to 167.4.79.254167.4.79.2552,046
139167.4.80.0/21167.4.80.1 to 167.4.87.254167.4.87.2552,046
140167.4.88.0/21167.4.88.1 to 167.4.95.254167.4.95.2552,046
141167.4.96.0/21167.4.96.1 to 167.4.103.254167.4.103.2552,046
142167.4.104.0/21167.4.104.1 to 167.4.111.254167.4.111.2552,046
143167.4.112.0/21167.4.112.1 to 167.4.119.254167.4.119.2552,046
144167.4.120.0/21167.4.120.1 to 167.4.127.254167.4.127.2552,046
145167.4.128.0/21167.4.128.1 to 167.4.135.254167.4.135.2552,046
146167.4.136.0/21167.4.136.1 to 167.4.143.254167.4.143.2552,046
147167.4.144.0/21167.4.144.1 to 167.4.151.254167.4.151.2552,046
148167.4.152.0/21167.4.152.1 to 167.4.159.254167.4.159.2552,046
149167.4.160.0/21167.4.160.1 to 167.4.167.254167.4.167.2552,046
150167.4.168.0/21167.4.168.1 to 167.4.175.254167.4.175.2552,046
151167.4.176.0/21167.4.176.1 to 167.4.183.254167.4.183.2552,046
152167.4.184.0/21167.4.184.1 to 167.4.191.254167.4.191.2552,046
153167.4.192.0/21167.4.192.1 to 167.4.199.254167.4.199.2552,046
154167.4.200.0/21167.4.200.1 to 167.4.207.254167.4.207.2552,046
155167.4.208.0/21167.4.208.1 to 167.4.215.254167.4.215.2552,046
156167.4.216.0/21167.4.216.1 to 167.4.223.254167.4.223.2552,046
157167.4.224.0/21167.4.224.1 to 167.4.231.254167.4.231.2552,046
158167.4.232.0/21167.4.232.1 to 167.4.239.254167.4.239.2552,046
159167.4.240.0/21167.4.240.1 to 167.4.247.254167.4.247.2552,046
160167.4.248.0/21167.4.248.1 to 167.4.255.254167.4.255.2552,046
161167.5.0.0/21167.5.0.1 to 167.5.7.254167.5.7.2552,046
162167.5.8.0/21167.5.8.1 to 167.5.15.254167.5.15.2552,046
163167.5.16.0/21167.5.16.1 to 167.5.23.254167.5.23.2552,046
164167.5.24.0/21167.5.24.1 to 167.5.31.254167.5.31.2552,046
165167.5.32.0/21167.5.32.1 to 167.5.39.254167.5.39.2552,046
166167.5.40.0/21167.5.40.1 to 167.5.47.254167.5.47.2552,046
167167.5.48.0/21167.5.48.1 to 167.5.55.254167.5.55.2552,046
168167.5.56.0/21167.5.56.1 to 167.5.63.254167.5.63.2552,046
169167.5.64.0/21167.5.64.1 to 167.5.71.254167.5.71.2552,046
170167.5.72.0/21167.5.72.1 to 167.5.79.254167.5.79.2552,046
171167.5.80.0/21167.5.80.1 to 167.5.87.254167.5.87.2552,046
172167.5.88.0/21167.5.88.1 to 167.5.95.254167.5.95.2552,046
173167.5.96.0/21167.5.96.1 to 167.5.103.254167.5.103.2552,046
174167.5.104.0/21167.5.104.1 to 167.5.111.254167.5.111.2552,046
175167.5.112.0/21167.5.112.1 to 167.5.119.254167.5.119.2552,046
176167.5.120.0/21167.5.120.1 to 167.5.127.254167.5.127.2552,046
177167.5.128.0/21167.5.128.1 to 167.5.135.254167.5.135.2552,046
178167.5.136.0/21167.5.136.1 to 167.5.143.254167.5.143.2552,046
179167.5.144.0/21167.5.144.1 to 167.5.151.254167.5.151.2552,046
180167.5.152.0/21167.5.152.1 to 167.5.159.254167.5.159.2552,046
181167.5.160.0/21167.5.160.1 to 167.5.167.254167.5.167.2552,046
182167.5.168.0/21167.5.168.1 to 167.5.175.254167.5.175.2552,046
183167.5.176.0/21167.5.176.1 to 167.5.183.254167.5.183.2552,046
184167.5.184.0/21167.5.184.1 to 167.5.191.254167.5.191.2552,046
185167.5.192.0/21167.5.192.1 to 167.5.199.254167.5.199.2552,046
186167.5.200.0/21167.5.200.1 to 167.5.207.254167.5.207.2552,046
187167.5.208.0/21167.5.208.1 to 167.5.215.254167.5.215.2552,046
188167.5.216.0/21167.5.216.1 to 167.5.223.254167.5.223.2552,046
189167.5.224.0/21167.5.224.1 to 167.5.231.254167.5.231.2552,046
190167.5.232.0/21167.5.232.1 to 167.5.239.254167.5.239.2552,046
191167.5.240.0/21167.5.240.1 to 167.5.247.254167.5.247.2552,046
192167.5.248.0/21167.5.248.1 to 167.5.255.254167.5.255.2552,046
193167.6.0.0/21167.6.0.1 to 167.6.7.254167.6.7.2552,046
194167.6.8.0/21167.6.8.1 to 167.6.15.254167.6.15.2552,046
195167.6.16.0/21167.6.16.1 to 167.6.23.254167.6.23.2552,046
196167.6.24.0/21167.6.24.1 to 167.6.31.254167.6.31.2552,046
197167.6.32.0/21167.6.32.1 to 167.6.39.254167.6.39.2552,046
198167.6.40.0/21167.6.40.1 to 167.6.47.254167.6.47.2552,046
199167.6.48.0/21167.6.48.1 to 167.6.55.254167.6.55.2552,046
200167.6.56.0/21167.6.56.1 to 167.6.63.254167.6.63.2552,046
201167.6.64.0/21167.6.64.1 to 167.6.71.254167.6.71.2552,046
202167.6.72.0/21167.6.72.1 to 167.6.79.254167.6.79.2552,046
203167.6.80.0/21167.6.80.1 to 167.6.87.254167.6.87.2552,046
204167.6.88.0/21167.6.88.1 to 167.6.95.254167.6.95.2552,046
205167.6.96.0/21167.6.96.1 to 167.6.103.254167.6.103.2552,046
206167.6.104.0/21167.6.104.1 to 167.6.111.254167.6.111.2552,046
207167.6.112.0/21167.6.112.1 to 167.6.119.254167.6.119.2552,046
208167.6.120.0/21167.6.120.1 to 167.6.127.254167.6.127.2552,046
209167.6.128.0/21167.6.128.1 to 167.6.135.254167.6.135.2552,046
210167.6.136.0/21167.6.136.1 to 167.6.143.254167.6.143.2552,046
211167.6.144.0/21167.6.144.1 to 167.6.151.254167.6.151.2552,046
212167.6.152.0/21167.6.152.1 to 167.6.159.254167.6.159.2552,046
213167.6.160.0/21167.6.160.1 to 167.6.167.254167.6.167.2552,046
214167.6.168.0/21167.6.168.1 to 167.6.175.254167.6.175.2552,046
215167.6.176.0/21167.6.176.1 to 167.6.183.254167.6.183.2552,046
216167.6.184.0/21167.6.184.1 to 167.6.191.254167.6.191.2552,046
217167.6.192.0/21167.6.192.1 to 167.6.199.254167.6.199.2552,046
218167.6.200.0/21167.6.200.1 to 167.6.207.254167.6.207.2552,046
219167.6.208.0/21167.6.208.1 to 167.6.215.254167.6.215.2552,046
220167.6.216.0/21167.6.216.1 to 167.6.223.254167.6.223.2552,046
221167.6.224.0/21167.6.224.1 to 167.6.231.254167.6.231.2552,046
222167.6.232.0/21167.6.232.1 to 167.6.239.254167.6.239.2552,046
223167.6.240.0/21167.6.240.1 to 167.6.247.254167.6.247.2552,046
224167.6.248.0/21167.6.248.1 to 167.6.255.254167.6.255.2552,046
225167.7.0.0/21167.7.0.1 to 167.7.7.254167.7.7.2552,046
226167.7.8.0/21167.7.8.1 to 167.7.15.254167.7.15.2552,046
227167.7.16.0/21167.7.16.1 to 167.7.23.254167.7.23.2552,046
228167.7.24.0/21167.7.24.1 to 167.7.31.254167.7.31.2552,046
229167.7.32.0/21167.7.32.1 to 167.7.39.254167.7.39.2552,046
230167.7.40.0/21167.7.40.1 to 167.7.47.254167.7.47.2552,046
231167.7.48.0/21167.7.48.1 to 167.7.55.254167.7.55.2552,046
232167.7.56.0/21167.7.56.1 to 167.7.63.254167.7.63.2552,046
233167.7.64.0/21167.7.64.1 to 167.7.71.254167.7.71.2552,046
234167.7.72.0/21167.7.72.1 to 167.7.79.254167.7.79.2552,046
235167.7.80.0/21167.7.80.1 to 167.7.87.254167.7.87.2552,046
236167.7.88.0/21167.7.88.1 to 167.7.95.254167.7.95.2552,046
237167.7.96.0/21167.7.96.1 to 167.7.103.254167.7.103.2552,046
238167.7.104.0/21167.7.104.1 to 167.7.111.254167.7.111.2552,046
239167.7.112.0/21167.7.112.1 to 167.7.119.254167.7.119.2552,046
240167.7.120.0/21167.7.120.1 to 167.7.127.254167.7.127.2552,046
241167.7.128.0/21167.7.128.1 to 167.7.135.254167.7.135.2552,046
242167.7.136.0/21167.7.136.1 to 167.7.143.254167.7.143.2552,046
243167.7.144.0/21167.7.144.1 to 167.7.151.254167.7.151.2552,046
244167.7.152.0/21167.7.152.1 to 167.7.159.254167.7.159.2552,046
245167.7.160.0/21167.7.160.1 to 167.7.167.254167.7.167.2552,046
246167.7.168.0/21167.7.168.1 to 167.7.175.254167.7.175.2552,046
247167.7.176.0/21167.7.176.1 to 167.7.183.254167.7.183.2552,046
248167.7.184.0/21167.7.184.1 to 167.7.191.254167.7.191.2552,046
249167.7.192.0/21167.7.192.1 to 167.7.199.254167.7.199.2552,046
250167.7.200.0/21167.7.200.1 to 167.7.207.254167.7.207.2552,046
251167.7.208.0/21167.7.208.1 to 167.7.215.254167.7.215.2552,046
252167.7.216.0/21167.7.216.1 to 167.7.223.254167.7.223.2552,046
253167.7.224.0/21167.7.224.1 to 167.7.231.254167.7.231.2552,046
254167.7.232.0/21167.7.232.1 to 167.7.239.254167.7.239.2552,046
255167.7.240.0/21167.7.240.1 to 167.7.247.254167.7.247.2552,046
256167.7.248.0/21167.7.248.1 to 167.7.255.254167.7.255.2552,046

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.