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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.

Network167.64.0.0/12
Usable hosts1,048,574
Subnet mask255.240.0.0
Addresses1,048,576
Network address
167.64.0.0
Broadcast address
167.79.255.255
First usable
167.64.0.1
Last usable
167.79.255.254
Usable hosts
1,048,574 (1,048,576 less the network and broadcast addresses)
Subnet mask
255.240.0.0
Wildcard mask
0.15.255.255 (Cisco ACLs, OSPF)
Prefix length
/12
Type
Public public
Old class
B (default /16)
As numbers
Hex A7400000 · Integer 2805989376 to 2807037951
Reverse DNS zones
64.167.in-addr.arpa
65.167.in-addr.arpa
66.167.in-addr.arpa
67.167.in-addr.arpa
68.167.in-addr.arpa
69.167.in-addr.arpa
70.167.in-addr.arpa
71.167.in-addr.arpa
72.167.in-addr.arpa
73.167.in-addr.arpa
74.167.in-addr.arpa
75.167.in-addr.arpa
76.167.in-addr.arpa
77.167.in-addr.arpa
78.167.in-addr.arpa
79.167.in-addr.arpa
/12 is not on a 8-bit boundary, so it takes 16 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10100111.01000000.00000000.00000000167.64.0.0
Subnet mask11111111.11110000.00000000.00000000255.240.0.0
Network10100111.01000000.00000000.00000000167.64.0.0
Broadcast10100111.01001111.11111111.11111111167.79.255.255
Split into smaller subnets/20
/13 (2)/14 (4)/15 (8)/16 (16)/17 (32)/18 (64)/19 (128)/20 (256)/21 (512)/22 (1,024)/23 (2,048)/24 (4,096)

167.64.0.0/12 makes 256 subnets of /20.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1167.64.0.0/20167.64.0.1 to 167.64.15.254167.64.15.2554,094
2167.64.16.0/20167.64.16.1 to 167.64.31.254167.64.31.2554,094
3167.64.32.0/20167.64.32.1 to 167.64.47.254167.64.47.2554,094
4167.64.48.0/20167.64.48.1 to 167.64.63.254167.64.63.2554,094
5167.64.64.0/20167.64.64.1 to 167.64.79.254167.64.79.2554,094
6167.64.80.0/20167.64.80.1 to 167.64.95.254167.64.95.2554,094
7167.64.96.0/20167.64.96.1 to 167.64.111.254167.64.111.2554,094
8167.64.112.0/20167.64.112.1 to 167.64.127.254167.64.127.2554,094
9167.64.128.0/20167.64.128.1 to 167.64.143.254167.64.143.2554,094
10167.64.144.0/20167.64.144.1 to 167.64.159.254167.64.159.2554,094
11167.64.160.0/20167.64.160.1 to 167.64.175.254167.64.175.2554,094
12167.64.176.0/20167.64.176.1 to 167.64.191.254167.64.191.2554,094
13167.64.192.0/20167.64.192.1 to 167.64.207.254167.64.207.2554,094
14167.64.208.0/20167.64.208.1 to 167.64.223.254167.64.223.2554,094
15167.64.224.0/20167.64.224.1 to 167.64.239.254167.64.239.2554,094
16167.64.240.0/20167.64.240.1 to 167.64.255.254167.64.255.2554,094
17167.65.0.0/20167.65.0.1 to 167.65.15.254167.65.15.2554,094
18167.65.16.0/20167.65.16.1 to 167.65.31.254167.65.31.2554,094
19167.65.32.0/20167.65.32.1 to 167.65.47.254167.65.47.2554,094
20167.65.48.0/20167.65.48.1 to 167.65.63.254167.65.63.2554,094
21167.65.64.0/20167.65.64.1 to 167.65.79.254167.65.79.2554,094
22167.65.80.0/20167.65.80.1 to 167.65.95.254167.65.95.2554,094
23167.65.96.0/20167.65.96.1 to 167.65.111.254167.65.111.2554,094
24167.65.112.0/20167.65.112.1 to 167.65.127.254167.65.127.2554,094
25167.65.128.0/20167.65.128.1 to 167.65.143.254167.65.143.2554,094
26167.65.144.0/20167.65.144.1 to 167.65.159.254167.65.159.2554,094
27167.65.160.0/20167.65.160.1 to 167.65.175.254167.65.175.2554,094
28167.65.176.0/20167.65.176.1 to 167.65.191.254167.65.191.2554,094
29167.65.192.0/20167.65.192.1 to 167.65.207.254167.65.207.2554,094
30167.65.208.0/20167.65.208.1 to 167.65.223.254167.65.223.2554,094
31167.65.224.0/20167.65.224.1 to 167.65.239.254167.65.239.2554,094
32167.65.240.0/20167.65.240.1 to 167.65.255.254167.65.255.2554,094
33167.66.0.0/20167.66.0.1 to 167.66.15.254167.66.15.2554,094
34167.66.16.0/20167.66.16.1 to 167.66.31.254167.66.31.2554,094
35167.66.32.0/20167.66.32.1 to 167.66.47.254167.66.47.2554,094
36167.66.48.0/20167.66.48.1 to 167.66.63.254167.66.63.2554,094
37167.66.64.0/20167.66.64.1 to 167.66.79.254167.66.79.2554,094
38167.66.80.0/20167.66.80.1 to 167.66.95.254167.66.95.2554,094
39167.66.96.0/20167.66.96.1 to 167.66.111.254167.66.111.2554,094
40167.66.112.0/20167.66.112.1 to 167.66.127.254167.66.127.2554,094
41167.66.128.0/20167.66.128.1 to 167.66.143.254167.66.143.2554,094
42167.66.144.0/20167.66.144.1 to 167.66.159.254167.66.159.2554,094
43167.66.160.0/20167.66.160.1 to 167.66.175.254167.66.175.2554,094
44167.66.176.0/20167.66.176.1 to 167.66.191.254167.66.191.2554,094
45167.66.192.0/20167.66.192.1 to 167.66.207.254167.66.207.2554,094
46167.66.208.0/20167.66.208.1 to 167.66.223.254167.66.223.2554,094
47167.66.224.0/20167.66.224.1 to 167.66.239.254167.66.239.2554,094
48167.66.240.0/20167.66.240.1 to 167.66.255.254167.66.255.2554,094
49167.67.0.0/20167.67.0.1 to 167.67.15.254167.67.15.2554,094
50167.67.16.0/20167.67.16.1 to 167.67.31.254167.67.31.2554,094
51167.67.32.0/20167.67.32.1 to 167.67.47.254167.67.47.2554,094
52167.67.48.0/20167.67.48.1 to 167.67.63.254167.67.63.2554,094
53167.67.64.0/20167.67.64.1 to 167.67.79.254167.67.79.2554,094
54167.67.80.0/20167.67.80.1 to 167.67.95.254167.67.95.2554,094
55167.67.96.0/20167.67.96.1 to 167.67.111.254167.67.111.2554,094
56167.67.112.0/20167.67.112.1 to 167.67.127.254167.67.127.2554,094
57167.67.128.0/20167.67.128.1 to 167.67.143.254167.67.143.2554,094
58167.67.144.0/20167.67.144.1 to 167.67.159.254167.67.159.2554,094
59167.67.160.0/20167.67.160.1 to 167.67.175.254167.67.175.2554,094
60167.67.176.0/20167.67.176.1 to 167.67.191.254167.67.191.2554,094
61167.67.192.0/20167.67.192.1 to 167.67.207.254167.67.207.2554,094
62167.67.208.0/20167.67.208.1 to 167.67.223.254167.67.223.2554,094
63167.67.224.0/20167.67.224.1 to 167.67.239.254167.67.239.2554,094
64167.67.240.0/20167.67.240.1 to 167.67.255.254167.67.255.2554,094
65167.68.0.0/20167.68.0.1 to 167.68.15.254167.68.15.2554,094
66167.68.16.0/20167.68.16.1 to 167.68.31.254167.68.31.2554,094
67167.68.32.0/20167.68.32.1 to 167.68.47.254167.68.47.2554,094
68167.68.48.0/20167.68.48.1 to 167.68.63.254167.68.63.2554,094
69167.68.64.0/20167.68.64.1 to 167.68.79.254167.68.79.2554,094
70167.68.80.0/20167.68.80.1 to 167.68.95.254167.68.95.2554,094
71167.68.96.0/20167.68.96.1 to 167.68.111.254167.68.111.2554,094
72167.68.112.0/20167.68.112.1 to 167.68.127.254167.68.127.2554,094
73167.68.128.0/20167.68.128.1 to 167.68.143.254167.68.143.2554,094
74167.68.144.0/20167.68.144.1 to 167.68.159.254167.68.159.2554,094
75167.68.160.0/20167.68.160.1 to 167.68.175.254167.68.175.2554,094
76167.68.176.0/20167.68.176.1 to 167.68.191.254167.68.191.2554,094
77167.68.192.0/20167.68.192.1 to 167.68.207.254167.68.207.2554,094
78167.68.208.0/20167.68.208.1 to 167.68.223.254167.68.223.2554,094
79167.68.224.0/20167.68.224.1 to 167.68.239.254167.68.239.2554,094
80167.68.240.0/20167.68.240.1 to 167.68.255.254167.68.255.2554,094
81167.69.0.0/20167.69.0.1 to 167.69.15.254167.69.15.2554,094
82167.69.16.0/20167.69.16.1 to 167.69.31.254167.69.31.2554,094
83167.69.32.0/20167.69.32.1 to 167.69.47.254167.69.47.2554,094
84167.69.48.0/20167.69.48.1 to 167.69.63.254167.69.63.2554,094
85167.69.64.0/20167.69.64.1 to 167.69.79.254167.69.79.2554,094
86167.69.80.0/20167.69.80.1 to 167.69.95.254167.69.95.2554,094
87167.69.96.0/20167.69.96.1 to 167.69.111.254167.69.111.2554,094
88167.69.112.0/20167.69.112.1 to 167.69.127.254167.69.127.2554,094
89167.69.128.0/20167.69.128.1 to 167.69.143.254167.69.143.2554,094
90167.69.144.0/20167.69.144.1 to 167.69.159.254167.69.159.2554,094
91167.69.160.0/20167.69.160.1 to 167.69.175.254167.69.175.2554,094
92167.69.176.0/20167.69.176.1 to 167.69.191.254167.69.191.2554,094
93167.69.192.0/20167.69.192.1 to 167.69.207.254167.69.207.2554,094
94167.69.208.0/20167.69.208.1 to 167.69.223.254167.69.223.2554,094
95167.69.224.0/20167.69.224.1 to 167.69.239.254167.69.239.2554,094
96167.69.240.0/20167.69.240.1 to 167.69.255.254167.69.255.2554,094
97167.70.0.0/20167.70.0.1 to 167.70.15.254167.70.15.2554,094
98167.70.16.0/20167.70.16.1 to 167.70.31.254167.70.31.2554,094
99167.70.32.0/20167.70.32.1 to 167.70.47.254167.70.47.2554,094
100167.70.48.0/20167.70.48.1 to 167.70.63.254167.70.63.2554,094
101167.70.64.0/20167.70.64.1 to 167.70.79.254167.70.79.2554,094
102167.70.80.0/20167.70.80.1 to 167.70.95.254167.70.95.2554,094
103167.70.96.0/20167.70.96.1 to 167.70.111.254167.70.111.2554,094
104167.70.112.0/20167.70.112.1 to 167.70.127.254167.70.127.2554,094
105167.70.128.0/20167.70.128.1 to 167.70.143.254167.70.143.2554,094
106167.70.144.0/20167.70.144.1 to 167.70.159.254167.70.159.2554,094
107167.70.160.0/20167.70.160.1 to 167.70.175.254167.70.175.2554,094
108167.70.176.0/20167.70.176.1 to 167.70.191.254167.70.191.2554,094
109167.70.192.0/20167.70.192.1 to 167.70.207.254167.70.207.2554,094
110167.70.208.0/20167.70.208.1 to 167.70.223.254167.70.223.2554,094
111167.70.224.0/20167.70.224.1 to 167.70.239.254167.70.239.2554,094
112167.70.240.0/20167.70.240.1 to 167.70.255.254167.70.255.2554,094
113167.71.0.0/20167.71.0.1 to 167.71.15.254167.71.15.2554,094
114167.71.16.0/20167.71.16.1 to 167.71.31.254167.71.31.2554,094
115167.71.32.0/20167.71.32.1 to 167.71.47.254167.71.47.2554,094
116167.71.48.0/20167.71.48.1 to 167.71.63.254167.71.63.2554,094
117167.71.64.0/20167.71.64.1 to 167.71.79.254167.71.79.2554,094
118167.71.80.0/20167.71.80.1 to 167.71.95.254167.71.95.2554,094
119167.71.96.0/20167.71.96.1 to 167.71.111.254167.71.111.2554,094
120167.71.112.0/20167.71.112.1 to 167.71.127.254167.71.127.2554,094
121167.71.128.0/20167.71.128.1 to 167.71.143.254167.71.143.2554,094
122167.71.144.0/20167.71.144.1 to 167.71.159.254167.71.159.2554,094
123167.71.160.0/20167.71.160.1 to 167.71.175.254167.71.175.2554,094
124167.71.176.0/20167.71.176.1 to 167.71.191.254167.71.191.2554,094
125167.71.192.0/20167.71.192.1 to 167.71.207.254167.71.207.2554,094
126167.71.208.0/20167.71.208.1 to 167.71.223.254167.71.223.2554,094
127167.71.224.0/20167.71.224.1 to 167.71.239.254167.71.239.2554,094
128167.71.240.0/20167.71.240.1 to 167.71.255.254167.71.255.2554,094
129167.72.0.0/20167.72.0.1 to 167.72.15.254167.72.15.2554,094
130167.72.16.0/20167.72.16.1 to 167.72.31.254167.72.31.2554,094
131167.72.32.0/20167.72.32.1 to 167.72.47.254167.72.47.2554,094
132167.72.48.0/20167.72.48.1 to 167.72.63.254167.72.63.2554,094
133167.72.64.0/20167.72.64.1 to 167.72.79.254167.72.79.2554,094
134167.72.80.0/20167.72.80.1 to 167.72.95.254167.72.95.2554,094
135167.72.96.0/20167.72.96.1 to 167.72.111.254167.72.111.2554,094
136167.72.112.0/20167.72.112.1 to 167.72.127.254167.72.127.2554,094
137167.72.128.0/20167.72.128.1 to 167.72.143.254167.72.143.2554,094
138167.72.144.0/20167.72.144.1 to 167.72.159.254167.72.159.2554,094
139167.72.160.0/20167.72.160.1 to 167.72.175.254167.72.175.2554,094
140167.72.176.0/20167.72.176.1 to 167.72.191.254167.72.191.2554,094
141167.72.192.0/20167.72.192.1 to 167.72.207.254167.72.207.2554,094
142167.72.208.0/20167.72.208.1 to 167.72.223.254167.72.223.2554,094
143167.72.224.0/20167.72.224.1 to 167.72.239.254167.72.239.2554,094
144167.72.240.0/20167.72.240.1 to 167.72.255.254167.72.255.2554,094
145167.73.0.0/20167.73.0.1 to 167.73.15.254167.73.15.2554,094
146167.73.16.0/20167.73.16.1 to 167.73.31.254167.73.31.2554,094
147167.73.32.0/20167.73.32.1 to 167.73.47.254167.73.47.2554,094
148167.73.48.0/20167.73.48.1 to 167.73.63.254167.73.63.2554,094
149167.73.64.0/20167.73.64.1 to 167.73.79.254167.73.79.2554,094
150167.73.80.0/20167.73.80.1 to 167.73.95.254167.73.95.2554,094
151167.73.96.0/20167.73.96.1 to 167.73.111.254167.73.111.2554,094
152167.73.112.0/20167.73.112.1 to 167.73.127.254167.73.127.2554,094
153167.73.128.0/20167.73.128.1 to 167.73.143.254167.73.143.2554,094
154167.73.144.0/20167.73.144.1 to 167.73.159.254167.73.159.2554,094
155167.73.160.0/20167.73.160.1 to 167.73.175.254167.73.175.2554,094
156167.73.176.0/20167.73.176.1 to 167.73.191.254167.73.191.2554,094
157167.73.192.0/20167.73.192.1 to 167.73.207.254167.73.207.2554,094
158167.73.208.0/20167.73.208.1 to 167.73.223.254167.73.223.2554,094
159167.73.224.0/20167.73.224.1 to 167.73.239.254167.73.239.2554,094
160167.73.240.0/20167.73.240.1 to 167.73.255.254167.73.255.2554,094
161167.74.0.0/20167.74.0.1 to 167.74.15.254167.74.15.2554,094
162167.74.16.0/20167.74.16.1 to 167.74.31.254167.74.31.2554,094
163167.74.32.0/20167.74.32.1 to 167.74.47.254167.74.47.2554,094
164167.74.48.0/20167.74.48.1 to 167.74.63.254167.74.63.2554,094
165167.74.64.0/20167.74.64.1 to 167.74.79.254167.74.79.2554,094
166167.74.80.0/20167.74.80.1 to 167.74.95.254167.74.95.2554,094
167167.74.96.0/20167.74.96.1 to 167.74.111.254167.74.111.2554,094
168167.74.112.0/20167.74.112.1 to 167.74.127.254167.74.127.2554,094
169167.74.128.0/20167.74.128.1 to 167.74.143.254167.74.143.2554,094
170167.74.144.0/20167.74.144.1 to 167.74.159.254167.74.159.2554,094
171167.74.160.0/20167.74.160.1 to 167.74.175.254167.74.175.2554,094
172167.74.176.0/20167.74.176.1 to 167.74.191.254167.74.191.2554,094
173167.74.192.0/20167.74.192.1 to 167.74.207.254167.74.207.2554,094
174167.74.208.0/20167.74.208.1 to 167.74.223.254167.74.223.2554,094
175167.74.224.0/20167.74.224.1 to 167.74.239.254167.74.239.2554,094
176167.74.240.0/20167.74.240.1 to 167.74.255.254167.74.255.2554,094
177167.75.0.0/20167.75.0.1 to 167.75.15.254167.75.15.2554,094
178167.75.16.0/20167.75.16.1 to 167.75.31.254167.75.31.2554,094
179167.75.32.0/20167.75.32.1 to 167.75.47.254167.75.47.2554,094
180167.75.48.0/20167.75.48.1 to 167.75.63.254167.75.63.2554,094
181167.75.64.0/20167.75.64.1 to 167.75.79.254167.75.79.2554,094
182167.75.80.0/20167.75.80.1 to 167.75.95.254167.75.95.2554,094
183167.75.96.0/20167.75.96.1 to 167.75.111.254167.75.111.2554,094
184167.75.112.0/20167.75.112.1 to 167.75.127.254167.75.127.2554,094
185167.75.128.0/20167.75.128.1 to 167.75.143.254167.75.143.2554,094
186167.75.144.0/20167.75.144.1 to 167.75.159.254167.75.159.2554,094
187167.75.160.0/20167.75.160.1 to 167.75.175.254167.75.175.2554,094
188167.75.176.0/20167.75.176.1 to 167.75.191.254167.75.191.2554,094
189167.75.192.0/20167.75.192.1 to 167.75.207.254167.75.207.2554,094
190167.75.208.0/20167.75.208.1 to 167.75.223.254167.75.223.2554,094
191167.75.224.0/20167.75.224.1 to 167.75.239.254167.75.239.2554,094
192167.75.240.0/20167.75.240.1 to 167.75.255.254167.75.255.2554,094
193167.76.0.0/20167.76.0.1 to 167.76.15.254167.76.15.2554,094
194167.76.16.0/20167.76.16.1 to 167.76.31.254167.76.31.2554,094
195167.76.32.0/20167.76.32.1 to 167.76.47.254167.76.47.2554,094
196167.76.48.0/20167.76.48.1 to 167.76.63.254167.76.63.2554,094
197167.76.64.0/20167.76.64.1 to 167.76.79.254167.76.79.2554,094
198167.76.80.0/20167.76.80.1 to 167.76.95.254167.76.95.2554,094
199167.76.96.0/20167.76.96.1 to 167.76.111.254167.76.111.2554,094
200167.76.112.0/20167.76.112.1 to 167.76.127.254167.76.127.2554,094
201167.76.128.0/20167.76.128.1 to 167.76.143.254167.76.143.2554,094
202167.76.144.0/20167.76.144.1 to 167.76.159.254167.76.159.2554,094
203167.76.160.0/20167.76.160.1 to 167.76.175.254167.76.175.2554,094
204167.76.176.0/20167.76.176.1 to 167.76.191.254167.76.191.2554,094
205167.76.192.0/20167.76.192.1 to 167.76.207.254167.76.207.2554,094
206167.76.208.0/20167.76.208.1 to 167.76.223.254167.76.223.2554,094
207167.76.224.0/20167.76.224.1 to 167.76.239.254167.76.239.2554,094
208167.76.240.0/20167.76.240.1 to 167.76.255.254167.76.255.2554,094
209167.77.0.0/20167.77.0.1 to 167.77.15.254167.77.15.2554,094
210167.77.16.0/20167.77.16.1 to 167.77.31.254167.77.31.2554,094
211167.77.32.0/20167.77.32.1 to 167.77.47.254167.77.47.2554,094
212167.77.48.0/20167.77.48.1 to 167.77.63.254167.77.63.2554,094
213167.77.64.0/20167.77.64.1 to 167.77.79.254167.77.79.2554,094
214167.77.80.0/20167.77.80.1 to 167.77.95.254167.77.95.2554,094
215167.77.96.0/20167.77.96.1 to 167.77.111.254167.77.111.2554,094
216167.77.112.0/20167.77.112.1 to 167.77.127.254167.77.127.2554,094
217167.77.128.0/20167.77.128.1 to 167.77.143.254167.77.143.2554,094
218167.77.144.0/20167.77.144.1 to 167.77.159.254167.77.159.2554,094
219167.77.160.0/20167.77.160.1 to 167.77.175.254167.77.175.2554,094
220167.77.176.0/20167.77.176.1 to 167.77.191.254167.77.191.2554,094
221167.77.192.0/20167.77.192.1 to 167.77.207.254167.77.207.2554,094
222167.77.208.0/20167.77.208.1 to 167.77.223.254167.77.223.2554,094
223167.77.224.0/20167.77.224.1 to 167.77.239.254167.77.239.2554,094
224167.77.240.0/20167.77.240.1 to 167.77.255.254167.77.255.2554,094
225167.78.0.0/20167.78.0.1 to 167.78.15.254167.78.15.2554,094
226167.78.16.0/20167.78.16.1 to 167.78.31.254167.78.31.2554,094
227167.78.32.0/20167.78.32.1 to 167.78.47.254167.78.47.2554,094
228167.78.48.0/20167.78.48.1 to 167.78.63.254167.78.63.2554,094
229167.78.64.0/20167.78.64.1 to 167.78.79.254167.78.79.2554,094
230167.78.80.0/20167.78.80.1 to 167.78.95.254167.78.95.2554,094
231167.78.96.0/20167.78.96.1 to 167.78.111.254167.78.111.2554,094
232167.78.112.0/20167.78.112.1 to 167.78.127.254167.78.127.2554,094
233167.78.128.0/20167.78.128.1 to 167.78.143.254167.78.143.2554,094
234167.78.144.0/20167.78.144.1 to 167.78.159.254167.78.159.2554,094
235167.78.160.0/20167.78.160.1 to 167.78.175.254167.78.175.2554,094
236167.78.176.0/20167.78.176.1 to 167.78.191.254167.78.191.2554,094
237167.78.192.0/20167.78.192.1 to 167.78.207.254167.78.207.2554,094
238167.78.208.0/20167.78.208.1 to 167.78.223.254167.78.223.2554,094
239167.78.224.0/20167.78.224.1 to 167.78.239.254167.78.239.2554,094
240167.78.240.0/20167.78.240.1 to 167.78.255.254167.78.255.2554,094
241167.79.0.0/20167.79.0.1 to 167.79.15.254167.79.15.2554,094
242167.79.16.0/20167.79.16.1 to 167.79.31.254167.79.31.2554,094
243167.79.32.0/20167.79.32.1 to 167.79.47.254167.79.47.2554,094
244167.79.48.0/20167.79.48.1 to 167.79.63.254167.79.63.2554,094
245167.79.64.0/20167.79.64.1 to 167.79.79.254167.79.79.2554,094
246167.79.80.0/20167.79.80.1 to 167.79.95.254167.79.95.2554,094
247167.79.96.0/20167.79.96.1 to 167.79.111.254167.79.111.2554,094
248167.79.112.0/20167.79.112.1 to 167.79.127.254167.79.127.2554,094
249167.79.128.0/20167.79.128.1 to 167.79.143.254167.79.143.2554,094
250167.79.144.0/20167.79.144.1 to 167.79.159.254167.79.159.2554,094
251167.79.160.0/20167.79.160.1 to 167.79.175.254167.79.175.2554,094
252167.79.176.0/20167.79.176.1 to 167.79.191.254167.79.191.2554,094
253167.79.192.0/20167.79.192.1 to 167.79.207.254167.79.207.2554,094
254167.79.208.0/20167.79.208.1 to 167.79.223.254167.79.223.2554,094
255167.79.224.0/20167.79.224.1 to 167.79.239.254167.79.239.2554,094
256167.79.240.0/20167.79.240.1 to 167.79.255.254167.79.255.2554,094

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.