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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.

Network122.128.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
122.128.0.0
Broadcast address
122.255.255.255
First usable
122.128.0.1
Last usable
122.255.255.254
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
A (default /8)
As numbers
Hex 7A800000 · Integer 2055208960 to 2063597567
Reverse DNS zones
128.122.in-addr.arpa
129.122.in-addr.arpa
130.122.in-addr.arpa
131.122.in-addr.arpa
132.122.in-addr.arpa
133.122.in-addr.arpa
134.122.in-addr.arpa
135.122.in-addr.arpa
136.122.in-addr.arpa
137.122.in-addr.arpa
138.122.in-addr.arpa
139.122.in-addr.arpa
140.122.in-addr.arpa
141.122.in-addr.arpa
142.122.in-addr.arpa
143.122.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
Address01111010.10000000.00000000.00000000122.128.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network01111010.10000000.00000000.00000000122.128.0.0
Broadcast01111010.11111111.11111111.11111111122.255.255.255
Split into smaller subnets/20
/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)

122.128.0.0/9 makes 2,048 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1122.128.0.0/20122.128.0.1 to 122.128.15.254122.128.15.2554,094
2122.128.16.0/20122.128.16.1 to 122.128.31.254122.128.31.2554,094
3122.128.32.0/20122.128.32.1 to 122.128.47.254122.128.47.2554,094
4122.128.48.0/20122.128.48.1 to 122.128.63.254122.128.63.2554,094
5122.128.64.0/20122.128.64.1 to 122.128.79.254122.128.79.2554,094
6122.128.80.0/20122.128.80.1 to 122.128.95.254122.128.95.2554,094
7122.128.96.0/20122.128.96.1 to 122.128.111.254122.128.111.2554,094
8122.128.112.0/20122.128.112.1 to 122.128.127.254122.128.127.2554,094
9122.128.128.0/20122.128.128.1 to 122.128.143.254122.128.143.2554,094
10122.128.144.0/20122.128.144.1 to 122.128.159.254122.128.159.2554,094
11122.128.160.0/20122.128.160.1 to 122.128.175.254122.128.175.2554,094
12122.128.176.0/20122.128.176.1 to 122.128.191.254122.128.191.2554,094
13122.128.192.0/20122.128.192.1 to 122.128.207.254122.128.207.2554,094
14122.128.208.0/20122.128.208.1 to 122.128.223.254122.128.223.2554,094
15122.128.224.0/20122.128.224.1 to 122.128.239.254122.128.239.2554,094
16122.128.240.0/20122.128.240.1 to 122.128.255.254122.128.255.2554,094
17122.129.0.0/20122.129.0.1 to 122.129.15.254122.129.15.2554,094
18122.129.16.0/20122.129.16.1 to 122.129.31.254122.129.31.2554,094
19122.129.32.0/20122.129.32.1 to 122.129.47.254122.129.47.2554,094
20122.129.48.0/20122.129.48.1 to 122.129.63.254122.129.63.2554,094
21122.129.64.0/20122.129.64.1 to 122.129.79.254122.129.79.2554,094
22122.129.80.0/20122.129.80.1 to 122.129.95.254122.129.95.2554,094
23122.129.96.0/20122.129.96.1 to 122.129.111.254122.129.111.2554,094
24122.129.112.0/20122.129.112.1 to 122.129.127.254122.129.127.2554,094
25122.129.128.0/20122.129.128.1 to 122.129.143.254122.129.143.2554,094
26122.129.144.0/20122.129.144.1 to 122.129.159.254122.129.159.2554,094
27122.129.160.0/20122.129.160.1 to 122.129.175.254122.129.175.2554,094
28122.129.176.0/20122.129.176.1 to 122.129.191.254122.129.191.2554,094
29122.129.192.0/20122.129.192.1 to 122.129.207.254122.129.207.2554,094
30122.129.208.0/20122.129.208.1 to 122.129.223.254122.129.223.2554,094
31122.129.224.0/20122.129.224.1 to 122.129.239.254122.129.239.2554,094
32122.129.240.0/20122.129.240.1 to 122.129.255.254122.129.255.2554,094
33122.130.0.0/20122.130.0.1 to 122.130.15.254122.130.15.2554,094
34122.130.16.0/20122.130.16.1 to 122.130.31.254122.130.31.2554,094
35122.130.32.0/20122.130.32.1 to 122.130.47.254122.130.47.2554,094
36122.130.48.0/20122.130.48.1 to 122.130.63.254122.130.63.2554,094
37122.130.64.0/20122.130.64.1 to 122.130.79.254122.130.79.2554,094
38122.130.80.0/20122.130.80.1 to 122.130.95.254122.130.95.2554,094
39122.130.96.0/20122.130.96.1 to 122.130.111.254122.130.111.2554,094
40122.130.112.0/20122.130.112.1 to 122.130.127.254122.130.127.2554,094
41122.130.128.0/20122.130.128.1 to 122.130.143.254122.130.143.2554,094
42122.130.144.0/20122.130.144.1 to 122.130.159.254122.130.159.2554,094
43122.130.160.0/20122.130.160.1 to 122.130.175.254122.130.175.2554,094
44122.130.176.0/20122.130.176.1 to 122.130.191.254122.130.191.2554,094
45122.130.192.0/20122.130.192.1 to 122.130.207.254122.130.207.2554,094
46122.130.208.0/20122.130.208.1 to 122.130.223.254122.130.223.2554,094
47122.130.224.0/20122.130.224.1 to 122.130.239.254122.130.239.2554,094
48122.130.240.0/20122.130.240.1 to 122.130.255.254122.130.255.2554,094
49122.131.0.0/20122.131.0.1 to 122.131.15.254122.131.15.2554,094
50122.131.16.0/20122.131.16.1 to 122.131.31.254122.131.31.2554,094
51122.131.32.0/20122.131.32.1 to 122.131.47.254122.131.47.2554,094
52122.131.48.0/20122.131.48.1 to 122.131.63.254122.131.63.2554,094
53122.131.64.0/20122.131.64.1 to 122.131.79.254122.131.79.2554,094
54122.131.80.0/20122.131.80.1 to 122.131.95.254122.131.95.2554,094
55122.131.96.0/20122.131.96.1 to 122.131.111.254122.131.111.2554,094
56122.131.112.0/20122.131.112.1 to 122.131.127.254122.131.127.2554,094
57122.131.128.0/20122.131.128.1 to 122.131.143.254122.131.143.2554,094
58122.131.144.0/20122.131.144.1 to 122.131.159.254122.131.159.2554,094
59122.131.160.0/20122.131.160.1 to 122.131.175.254122.131.175.2554,094
60122.131.176.0/20122.131.176.1 to 122.131.191.254122.131.191.2554,094
61122.131.192.0/20122.131.192.1 to 122.131.207.254122.131.207.2554,094
62122.131.208.0/20122.131.208.1 to 122.131.223.254122.131.223.2554,094
63122.131.224.0/20122.131.224.1 to 122.131.239.254122.131.239.2554,094
64122.131.240.0/20122.131.240.1 to 122.131.255.254122.131.255.2554,094
65122.132.0.0/20122.132.0.1 to 122.132.15.254122.132.15.2554,094
66122.132.16.0/20122.132.16.1 to 122.132.31.254122.132.31.2554,094
67122.132.32.0/20122.132.32.1 to 122.132.47.254122.132.47.2554,094
68122.132.48.0/20122.132.48.1 to 122.132.63.254122.132.63.2554,094
69122.132.64.0/20122.132.64.1 to 122.132.79.254122.132.79.2554,094
70122.132.80.0/20122.132.80.1 to 122.132.95.254122.132.95.2554,094
71122.132.96.0/20122.132.96.1 to 122.132.111.254122.132.111.2554,094
72122.132.112.0/20122.132.112.1 to 122.132.127.254122.132.127.2554,094
73122.132.128.0/20122.132.128.1 to 122.132.143.254122.132.143.2554,094
74122.132.144.0/20122.132.144.1 to 122.132.159.254122.132.159.2554,094
75122.132.160.0/20122.132.160.1 to 122.132.175.254122.132.175.2554,094
76122.132.176.0/20122.132.176.1 to 122.132.191.254122.132.191.2554,094
77122.132.192.0/20122.132.192.1 to 122.132.207.254122.132.207.2554,094
78122.132.208.0/20122.132.208.1 to 122.132.223.254122.132.223.2554,094
79122.132.224.0/20122.132.224.1 to 122.132.239.254122.132.239.2554,094
80122.132.240.0/20122.132.240.1 to 122.132.255.254122.132.255.2554,094
81122.133.0.0/20122.133.0.1 to 122.133.15.254122.133.15.2554,094
82122.133.16.0/20122.133.16.1 to 122.133.31.254122.133.31.2554,094
83122.133.32.0/20122.133.32.1 to 122.133.47.254122.133.47.2554,094
84122.133.48.0/20122.133.48.1 to 122.133.63.254122.133.63.2554,094
85122.133.64.0/20122.133.64.1 to 122.133.79.254122.133.79.2554,094
86122.133.80.0/20122.133.80.1 to 122.133.95.254122.133.95.2554,094
87122.133.96.0/20122.133.96.1 to 122.133.111.254122.133.111.2554,094
88122.133.112.0/20122.133.112.1 to 122.133.127.254122.133.127.2554,094
89122.133.128.0/20122.133.128.1 to 122.133.143.254122.133.143.2554,094
90122.133.144.0/20122.133.144.1 to 122.133.159.254122.133.159.2554,094
91122.133.160.0/20122.133.160.1 to 122.133.175.254122.133.175.2554,094
92122.133.176.0/20122.133.176.1 to 122.133.191.254122.133.191.2554,094
93122.133.192.0/20122.133.192.1 to 122.133.207.254122.133.207.2554,094
94122.133.208.0/20122.133.208.1 to 122.133.223.254122.133.223.2554,094
95122.133.224.0/20122.133.224.1 to 122.133.239.254122.133.239.2554,094
96122.133.240.0/20122.133.240.1 to 122.133.255.254122.133.255.2554,094
97122.134.0.0/20122.134.0.1 to 122.134.15.254122.134.15.2554,094
98122.134.16.0/20122.134.16.1 to 122.134.31.254122.134.31.2554,094
99122.134.32.0/20122.134.32.1 to 122.134.47.254122.134.47.2554,094
100122.134.48.0/20122.134.48.1 to 122.134.63.254122.134.63.2554,094
101122.134.64.0/20122.134.64.1 to 122.134.79.254122.134.79.2554,094
102122.134.80.0/20122.134.80.1 to 122.134.95.254122.134.95.2554,094
103122.134.96.0/20122.134.96.1 to 122.134.111.254122.134.111.2554,094
104122.134.112.0/20122.134.112.1 to 122.134.127.254122.134.127.2554,094
105122.134.128.0/20122.134.128.1 to 122.134.143.254122.134.143.2554,094
106122.134.144.0/20122.134.144.1 to 122.134.159.254122.134.159.2554,094
107122.134.160.0/20122.134.160.1 to 122.134.175.254122.134.175.2554,094
108122.134.176.0/20122.134.176.1 to 122.134.191.254122.134.191.2554,094
109122.134.192.0/20122.134.192.1 to 122.134.207.254122.134.207.2554,094
110122.134.208.0/20122.134.208.1 to 122.134.223.254122.134.223.2554,094
111122.134.224.0/20122.134.224.1 to 122.134.239.254122.134.239.2554,094
112122.134.240.0/20122.134.240.1 to 122.134.255.254122.134.255.2554,094
113122.135.0.0/20122.135.0.1 to 122.135.15.254122.135.15.2554,094
114122.135.16.0/20122.135.16.1 to 122.135.31.254122.135.31.2554,094
115122.135.32.0/20122.135.32.1 to 122.135.47.254122.135.47.2554,094
116122.135.48.0/20122.135.48.1 to 122.135.63.254122.135.63.2554,094
117122.135.64.0/20122.135.64.1 to 122.135.79.254122.135.79.2554,094
118122.135.80.0/20122.135.80.1 to 122.135.95.254122.135.95.2554,094
119122.135.96.0/20122.135.96.1 to 122.135.111.254122.135.111.2554,094
120122.135.112.0/20122.135.112.1 to 122.135.127.254122.135.127.2554,094
121122.135.128.0/20122.135.128.1 to 122.135.143.254122.135.143.2554,094
122122.135.144.0/20122.135.144.1 to 122.135.159.254122.135.159.2554,094
123122.135.160.0/20122.135.160.1 to 122.135.175.254122.135.175.2554,094
124122.135.176.0/20122.135.176.1 to 122.135.191.254122.135.191.2554,094
125122.135.192.0/20122.135.192.1 to 122.135.207.254122.135.207.2554,094
126122.135.208.0/20122.135.208.1 to 122.135.223.254122.135.223.2554,094
127122.135.224.0/20122.135.224.1 to 122.135.239.254122.135.239.2554,094
128122.135.240.0/20122.135.240.1 to 122.135.255.254122.135.255.2554,094
129122.136.0.0/20122.136.0.1 to 122.136.15.254122.136.15.2554,094
130122.136.16.0/20122.136.16.1 to 122.136.31.254122.136.31.2554,094
131122.136.32.0/20122.136.32.1 to 122.136.47.254122.136.47.2554,094
132122.136.48.0/20122.136.48.1 to 122.136.63.254122.136.63.2554,094
133122.136.64.0/20122.136.64.1 to 122.136.79.254122.136.79.2554,094
134122.136.80.0/20122.136.80.1 to 122.136.95.254122.136.95.2554,094
135122.136.96.0/20122.136.96.1 to 122.136.111.254122.136.111.2554,094
136122.136.112.0/20122.136.112.1 to 122.136.127.254122.136.127.2554,094
137122.136.128.0/20122.136.128.1 to 122.136.143.254122.136.143.2554,094
138122.136.144.0/20122.136.144.1 to 122.136.159.254122.136.159.2554,094
139122.136.160.0/20122.136.160.1 to 122.136.175.254122.136.175.2554,094
140122.136.176.0/20122.136.176.1 to 122.136.191.254122.136.191.2554,094
141122.136.192.0/20122.136.192.1 to 122.136.207.254122.136.207.2554,094
142122.136.208.0/20122.136.208.1 to 122.136.223.254122.136.223.2554,094
143122.136.224.0/20122.136.224.1 to 122.136.239.254122.136.239.2554,094
144122.136.240.0/20122.136.240.1 to 122.136.255.254122.136.255.2554,094
145122.137.0.0/20122.137.0.1 to 122.137.15.254122.137.15.2554,094
146122.137.16.0/20122.137.16.1 to 122.137.31.254122.137.31.2554,094
147122.137.32.0/20122.137.32.1 to 122.137.47.254122.137.47.2554,094
148122.137.48.0/20122.137.48.1 to 122.137.63.254122.137.63.2554,094
149122.137.64.0/20122.137.64.1 to 122.137.79.254122.137.79.2554,094
150122.137.80.0/20122.137.80.1 to 122.137.95.254122.137.95.2554,094
151122.137.96.0/20122.137.96.1 to 122.137.111.254122.137.111.2554,094
152122.137.112.0/20122.137.112.1 to 122.137.127.254122.137.127.2554,094
153122.137.128.0/20122.137.128.1 to 122.137.143.254122.137.143.2554,094
154122.137.144.0/20122.137.144.1 to 122.137.159.254122.137.159.2554,094
155122.137.160.0/20122.137.160.1 to 122.137.175.254122.137.175.2554,094
156122.137.176.0/20122.137.176.1 to 122.137.191.254122.137.191.2554,094
157122.137.192.0/20122.137.192.1 to 122.137.207.254122.137.207.2554,094
158122.137.208.0/20122.137.208.1 to 122.137.223.254122.137.223.2554,094
159122.137.224.0/20122.137.224.1 to 122.137.239.254122.137.239.2554,094
160122.137.240.0/20122.137.240.1 to 122.137.255.254122.137.255.2554,094
161122.138.0.0/20122.138.0.1 to 122.138.15.254122.138.15.2554,094
162122.138.16.0/20122.138.16.1 to 122.138.31.254122.138.31.2554,094
163122.138.32.0/20122.138.32.1 to 122.138.47.254122.138.47.2554,094
164122.138.48.0/20122.138.48.1 to 122.138.63.254122.138.63.2554,094
165122.138.64.0/20122.138.64.1 to 122.138.79.254122.138.79.2554,094
166122.138.80.0/20122.138.80.1 to 122.138.95.254122.138.95.2554,094
167122.138.96.0/20122.138.96.1 to 122.138.111.254122.138.111.2554,094
168122.138.112.0/20122.138.112.1 to 122.138.127.254122.138.127.2554,094
169122.138.128.0/20122.138.128.1 to 122.138.143.254122.138.143.2554,094
170122.138.144.0/20122.138.144.1 to 122.138.159.254122.138.159.2554,094
171122.138.160.0/20122.138.160.1 to 122.138.175.254122.138.175.2554,094
172122.138.176.0/20122.138.176.1 to 122.138.191.254122.138.191.2554,094
173122.138.192.0/20122.138.192.1 to 122.138.207.254122.138.207.2554,094
174122.138.208.0/20122.138.208.1 to 122.138.223.254122.138.223.2554,094
175122.138.224.0/20122.138.224.1 to 122.138.239.254122.138.239.2554,094
176122.138.240.0/20122.138.240.1 to 122.138.255.254122.138.255.2554,094
177122.139.0.0/20122.139.0.1 to 122.139.15.254122.139.15.2554,094
178122.139.16.0/20122.139.16.1 to 122.139.31.254122.139.31.2554,094
179122.139.32.0/20122.139.32.1 to 122.139.47.254122.139.47.2554,094
180122.139.48.0/20122.139.48.1 to 122.139.63.254122.139.63.2554,094
181122.139.64.0/20122.139.64.1 to 122.139.79.254122.139.79.2554,094
182122.139.80.0/20122.139.80.1 to 122.139.95.254122.139.95.2554,094
183122.139.96.0/20122.139.96.1 to 122.139.111.254122.139.111.2554,094
184122.139.112.0/20122.139.112.1 to 122.139.127.254122.139.127.2554,094
185122.139.128.0/20122.139.128.1 to 122.139.143.254122.139.143.2554,094
186122.139.144.0/20122.139.144.1 to 122.139.159.254122.139.159.2554,094
187122.139.160.0/20122.139.160.1 to 122.139.175.254122.139.175.2554,094
188122.139.176.0/20122.139.176.1 to 122.139.191.254122.139.191.2554,094
189122.139.192.0/20122.139.192.1 to 122.139.207.254122.139.207.2554,094
190122.139.208.0/20122.139.208.1 to 122.139.223.254122.139.223.2554,094
191122.139.224.0/20122.139.224.1 to 122.139.239.254122.139.239.2554,094
192122.139.240.0/20122.139.240.1 to 122.139.255.254122.139.255.2554,094
193122.140.0.0/20122.140.0.1 to 122.140.15.254122.140.15.2554,094
194122.140.16.0/20122.140.16.1 to 122.140.31.254122.140.31.2554,094
195122.140.32.0/20122.140.32.1 to 122.140.47.254122.140.47.2554,094
196122.140.48.0/20122.140.48.1 to 122.140.63.254122.140.63.2554,094
197122.140.64.0/20122.140.64.1 to 122.140.79.254122.140.79.2554,094
198122.140.80.0/20122.140.80.1 to 122.140.95.254122.140.95.2554,094
199122.140.96.0/20122.140.96.1 to 122.140.111.254122.140.111.2554,094
200122.140.112.0/20122.140.112.1 to 122.140.127.254122.140.127.2554,094
201122.140.128.0/20122.140.128.1 to 122.140.143.254122.140.143.2554,094
202122.140.144.0/20122.140.144.1 to 122.140.159.254122.140.159.2554,094
203122.140.160.0/20122.140.160.1 to 122.140.175.254122.140.175.2554,094
204122.140.176.0/20122.140.176.1 to 122.140.191.254122.140.191.2554,094
205122.140.192.0/20122.140.192.1 to 122.140.207.254122.140.207.2554,094
206122.140.208.0/20122.140.208.1 to 122.140.223.254122.140.223.2554,094
207122.140.224.0/20122.140.224.1 to 122.140.239.254122.140.239.2554,094
208122.140.240.0/20122.140.240.1 to 122.140.255.254122.140.255.2554,094
209122.141.0.0/20122.141.0.1 to 122.141.15.254122.141.15.2554,094
210122.141.16.0/20122.141.16.1 to 122.141.31.254122.141.31.2554,094
211122.141.32.0/20122.141.32.1 to 122.141.47.254122.141.47.2554,094
212122.141.48.0/20122.141.48.1 to 122.141.63.254122.141.63.2554,094
213122.141.64.0/20122.141.64.1 to 122.141.79.254122.141.79.2554,094
214122.141.80.0/20122.141.80.1 to 122.141.95.254122.141.95.2554,094
215122.141.96.0/20122.141.96.1 to 122.141.111.254122.141.111.2554,094
216122.141.112.0/20122.141.112.1 to 122.141.127.254122.141.127.2554,094
217122.141.128.0/20122.141.128.1 to 122.141.143.254122.141.143.2554,094
218122.141.144.0/20122.141.144.1 to 122.141.159.254122.141.159.2554,094
219122.141.160.0/20122.141.160.1 to 122.141.175.254122.141.175.2554,094
220122.141.176.0/20122.141.176.1 to 122.141.191.254122.141.191.2554,094
221122.141.192.0/20122.141.192.1 to 122.141.207.254122.141.207.2554,094
222122.141.208.0/20122.141.208.1 to 122.141.223.254122.141.223.2554,094
223122.141.224.0/20122.141.224.1 to 122.141.239.254122.141.239.2554,094
224122.141.240.0/20122.141.240.1 to 122.141.255.254122.141.255.2554,094
225122.142.0.0/20122.142.0.1 to 122.142.15.254122.142.15.2554,094
226122.142.16.0/20122.142.16.1 to 122.142.31.254122.142.31.2554,094
227122.142.32.0/20122.142.32.1 to 122.142.47.254122.142.47.2554,094
228122.142.48.0/20122.142.48.1 to 122.142.63.254122.142.63.2554,094
229122.142.64.0/20122.142.64.1 to 122.142.79.254122.142.79.2554,094
230122.142.80.0/20122.142.80.1 to 122.142.95.254122.142.95.2554,094
231122.142.96.0/20122.142.96.1 to 122.142.111.254122.142.111.2554,094
232122.142.112.0/20122.142.112.1 to 122.142.127.254122.142.127.2554,094
233122.142.128.0/20122.142.128.1 to 122.142.143.254122.142.143.2554,094
234122.142.144.0/20122.142.144.1 to 122.142.159.254122.142.159.2554,094
235122.142.160.0/20122.142.160.1 to 122.142.175.254122.142.175.2554,094
236122.142.176.0/20122.142.176.1 to 122.142.191.254122.142.191.2554,094
237122.142.192.0/20122.142.192.1 to 122.142.207.254122.142.207.2554,094
238122.142.208.0/20122.142.208.1 to 122.142.223.254122.142.223.2554,094
239122.142.224.0/20122.142.224.1 to 122.142.239.254122.142.239.2554,094
240122.142.240.0/20122.142.240.1 to 122.142.255.254122.142.255.2554,094
241122.143.0.0/20122.143.0.1 to 122.143.15.254122.143.15.2554,094
242122.143.16.0/20122.143.16.1 to 122.143.31.254122.143.31.2554,094
243122.143.32.0/20122.143.32.1 to 122.143.47.254122.143.47.2554,094
244122.143.48.0/20122.143.48.1 to 122.143.63.254122.143.63.2554,094
245122.143.64.0/20122.143.64.1 to 122.143.79.254122.143.79.2554,094
246122.143.80.0/20122.143.80.1 to 122.143.95.254122.143.95.2554,094
247122.143.96.0/20122.143.96.1 to 122.143.111.254122.143.111.2554,094
248122.143.112.0/20122.143.112.1 to 122.143.127.254122.143.127.2554,094
249122.143.128.0/20122.143.128.1 to 122.143.143.254122.143.143.2554,094
250122.143.144.0/20122.143.144.1 to 122.143.159.254122.143.159.2554,094
251122.143.160.0/20122.143.160.1 to 122.143.175.254122.143.175.2554,094
252122.143.176.0/20122.143.176.1 to 122.143.191.254122.143.191.2554,094
253122.143.192.0/20122.143.192.1 to 122.143.207.254122.143.207.2554,094
254122.143.208.0/20122.143.208.1 to 122.143.223.254122.143.223.2554,094
255122.143.224.0/20122.143.224.1 to 122.143.239.254122.143.239.2554,094
256122.143.240.0/20122.143.240.1 to 122.143.255.254122.143.255.2554,094

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.