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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.

Network122.0.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
122.0.0.0
Broadcast address
122.127.255.255
First usable
122.0.0.1
Last usable
122.127.255.254
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
A (default /8)
As numbers
Hex 7A000000 · Integer 2046820352 to 2055208959
Reverse DNS zones
0.122.in-addr.arpa
1.122.in-addr.arpa
2.122.in-addr.arpa
3.122.in-addr.arpa
4.122.in-addr.arpa
5.122.in-addr.arpa
6.122.in-addr.arpa
7.122.in-addr.arpa
8.122.in-addr.arpa
9.122.in-addr.arpa
10.122.in-addr.arpa
11.122.in-addr.arpa
12.122.in-addr.arpa
13.122.in-addr.arpa
14.122.in-addr.arpa
15.122.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
Address01111010.00000000.00000000.00000000122.0.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network01111010.00000000.00000000.00000000122.0.0.0
Broadcast01111010.01111111.11111111.11111111122.127.255.255
Split into smaller subnets/19
/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)

122.0.0.0/9 makes 1,024 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1122.0.0.0/19122.0.0.1 to 122.0.31.254122.0.31.2558,190
2122.0.32.0/19122.0.32.1 to 122.0.63.254122.0.63.2558,190
3122.0.64.0/19122.0.64.1 to 122.0.95.254122.0.95.2558,190
4122.0.96.0/19122.0.96.1 to 122.0.127.254122.0.127.2558,190
5122.0.128.0/19122.0.128.1 to 122.0.159.254122.0.159.2558,190
6122.0.160.0/19122.0.160.1 to 122.0.191.254122.0.191.2558,190
7122.0.192.0/19122.0.192.1 to 122.0.223.254122.0.223.2558,190
8122.0.224.0/19122.0.224.1 to 122.0.255.254122.0.255.2558,190
9122.1.0.0/19122.1.0.1 to 122.1.31.254122.1.31.2558,190
10122.1.32.0/19122.1.32.1 to 122.1.63.254122.1.63.2558,190
11122.1.64.0/19122.1.64.1 to 122.1.95.254122.1.95.2558,190
12122.1.96.0/19122.1.96.1 to 122.1.127.254122.1.127.2558,190
13122.1.128.0/19122.1.128.1 to 122.1.159.254122.1.159.2558,190
14122.1.160.0/19122.1.160.1 to 122.1.191.254122.1.191.2558,190
15122.1.192.0/19122.1.192.1 to 122.1.223.254122.1.223.2558,190
16122.1.224.0/19122.1.224.1 to 122.1.255.254122.1.255.2558,190
17122.2.0.0/19122.2.0.1 to 122.2.31.254122.2.31.2558,190
18122.2.32.0/19122.2.32.1 to 122.2.63.254122.2.63.2558,190
19122.2.64.0/19122.2.64.1 to 122.2.95.254122.2.95.2558,190
20122.2.96.0/19122.2.96.1 to 122.2.127.254122.2.127.2558,190
21122.2.128.0/19122.2.128.1 to 122.2.159.254122.2.159.2558,190
22122.2.160.0/19122.2.160.1 to 122.2.191.254122.2.191.2558,190
23122.2.192.0/19122.2.192.1 to 122.2.223.254122.2.223.2558,190
24122.2.224.0/19122.2.224.1 to 122.2.255.254122.2.255.2558,190
25122.3.0.0/19122.3.0.1 to 122.3.31.254122.3.31.2558,190
26122.3.32.0/19122.3.32.1 to 122.3.63.254122.3.63.2558,190
27122.3.64.0/19122.3.64.1 to 122.3.95.254122.3.95.2558,190
28122.3.96.0/19122.3.96.1 to 122.3.127.254122.3.127.2558,190
29122.3.128.0/19122.3.128.1 to 122.3.159.254122.3.159.2558,190
30122.3.160.0/19122.3.160.1 to 122.3.191.254122.3.191.2558,190
31122.3.192.0/19122.3.192.1 to 122.3.223.254122.3.223.2558,190
32122.3.224.0/19122.3.224.1 to 122.3.255.254122.3.255.2558,190
33122.4.0.0/19122.4.0.1 to 122.4.31.254122.4.31.2558,190
34122.4.32.0/19122.4.32.1 to 122.4.63.254122.4.63.2558,190
35122.4.64.0/19122.4.64.1 to 122.4.95.254122.4.95.2558,190
36122.4.96.0/19122.4.96.1 to 122.4.127.254122.4.127.2558,190
37122.4.128.0/19122.4.128.1 to 122.4.159.254122.4.159.2558,190
38122.4.160.0/19122.4.160.1 to 122.4.191.254122.4.191.2558,190
39122.4.192.0/19122.4.192.1 to 122.4.223.254122.4.223.2558,190
40122.4.224.0/19122.4.224.1 to 122.4.255.254122.4.255.2558,190
41122.5.0.0/19122.5.0.1 to 122.5.31.254122.5.31.2558,190
42122.5.32.0/19122.5.32.1 to 122.5.63.254122.5.63.2558,190
43122.5.64.0/19122.5.64.1 to 122.5.95.254122.5.95.2558,190
44122.5.96.0/19122.5.96.1 to 122.5.127.254122.5.127.2558,190
45122.5.128.0/19122.5.128.1 to 122.5.159.254122.5.159.2558,190
46122.5.160.0/19122.5.160.1 to 122.5.191.254122.5.191.2558,190
47122.5.192.0/19122.5.192.1 to 122.5.223.254122.5.223.2558,190
48122.5.224.0/19122.5.224.1 to 122.5.255.254122.5.255.2558,190
49122.6.0.0/19122.6.0.1 to 122.6.31.254122.6.31.2558,190
50122.6.32.0/19122.6.32.1 to 122.6.63.254122.6.63.2558,190
51122.6.64.0/19122.6.64.1 to 122.6.95.254122.6.95.2558,190
52122.6.96.0/19122.6.96.1 to 122.6.127.254122.6.127.2558,190
53122.6.128.0/19122.6.128.1 to 122.6.159.254122.6.159.2558,190
54122.6.160.0/19122.6.160.1 to 122.6.191.254122.6.191.2558,190
55122.6.192.0/19122.6.192.1 to 122.6.223.254122.6.223.2558,190
56122.6.224.0/19122.6.224.1 to 122.6.255.254122.6.255.2558,190
57122.7.0.0/19122.7.0.1 to 122.7.31.254122.7.31.2558,190
58122.7.32.0/19122.7.32.1 to 122.7.63.254122.7.63.2558,190
59122.7.64.0/19122.7.64.1 to 122.7.95.254122.7.95.2558,190
60122.7.96.0/19122.7.96.1 to 122.7.127.254122.7.127.2558,190
61122.7.128.0/19122.7.128.1 to 122.7.159.254122.7.159.2558,190
62122.7.160.0/19122.7.160.1 to 122.7.191.254122.7.191.2558,190
63122.7.192.0/19122.7.192.1 to 122.7.223.254122.7.223.2558,190
64122.7.224.0/19122.7.224.1 to 122.7.255.254122.7.255.2558,190
65122.8.0.0/19122.8.0.1 to 122.8.31.254122.8.31.2558,190
66122.8.32.0/19122.8.32.1 to 122.8.63.254122.8.63.2558,190
67122.8.64.0/19122.8.64.1 to 122.8.95.254122.8.95.2558,190
68122.8.96.0/19122.8.96.1 to 122.8.127.254122.8.127.2558,190
69122.8.128.0/19122.8.128.1 to 122.8.159.254122.8.159.2558,190
70122.8.160.0/19122.8.160.1 to 122.8.191.254122.8.191.2558,190
71122.8.192.0/19122.8.192.1 to 122.8.223.254122.8.223.2558,190
72122.8.224.0/19122.8.224.1 to 122.8.255.254122.8.255.2558,190
73122.9.0.0/19122.9.0.1 to 122.9.31.254122.9.31.2558,190
74122.9.32.0/19122.9.32.1 to 122.9.63.254122.9.63.2558,190
75122.9.64.0/19122.9.64.1 to 122.9.95.254122.9.95.2558,190
76122.9.96.0/19122.9.96.1 to 122.9.127.254122.9.127.2558,190
77122.9.128.0/19122.9.128.1 to 122.9.159.254122.9.159.2558,190
78122.9.160.0/19122.9.160.1 to 122.9.191.254122.9.191.2558,190
79122.9.192.0/19122.9.192.1 to 122.9.223.254122.9.223.2558,190
80122.9.224.0/19122.9.224.1 to 122.9.255.254122.9.255.2558,190
81122.10.0.0/19122.10.0.1 to 122.10.31.254122.10.31.2558,190
82122.10.32.0/19122.10.32.1 to 122.10.63.254122.10.63.2558,190
83122.10.64.0/19122.10.64.1 to 122.10.95.254122.10.95.2558,190
84122.10.96.0/19122.10.96.1 to 122.10.127.254122.10.127.2558,190
85122.10.128.0/19122.10.128.1 to 122.10.159.254122.10.159.2558,190
86122.10.160.0/19122.10.160.1 to 122.10.191.254122.10.191.2558,190
87122.10.192.0/19122.10.192.1 to 122.10.223.254122.10.223.2558,190
88122.10.224.0/19122.10.224.1 to 122.10.255.254122.10.255.2558,190
89122.11.0.0/19122.11.0.1 to 122.11.31.254122.11.31.2558,190
90122.11.32.0/19122.11.32.1 to 122.11.63.254122.11.63.2558,190
91122.11.64.0/19122.11.64.1 to 122.11.95.254122.11.95.2558,190
92122.11.96.0/19122.11.96.1 to 122.11.127.254122.11.127.2558,190
93122.11.128.0/19122.11.128.1 to 122.11.159.254122.11.159.2558,190
94122.11.160.0/19122.11.160.1 to 122.11.191.254122.11.191.2558,190
95122.11.192.0/19122.11.192.1 to 122.11.223.254122.11.223.2558,190
96122.11.224.0/19122.11.224.1 to 122.11.255.254122.11.255.2558,190
97122.12.0.0/19122.12.0.1 to 122.12.31.254122.12.31.2558,190
98122.12.32.0/19122.12.32.1 to 122.12.63.254122.12.63.2558,190
99122.12.64.0/19122.12.64.1 to 122.12.95.254122.12.95.2558,190
100122.12.96.0/19122.12.96.1 to 122.12.127.254122.12.127.2558,190
101122.12.128.0/19122.12.128.1 to 122.12.159.254122.12.159.2558,190
102122.12.160.0/19122.12.160.1 to 122.12.191.254122.12.191.2558,190
103122.12.192.0/19122.12.192.1 to 122.12.223.254122.12.223.2558,190
104122.12.224.0/19122.12.224.1 to 122.12.255.254122.12.255.2558,190
105122.13.0.0/19122.13.0.1 to 122.13.31.254122.13.31.2558,190
106122.13.32.0/19122.13.32.1 to 122.13.63.254122.13.63.2558,190
107122.13.64.0/19122.13.64.1 to 122.13.95.254122.13.95.2558,190
108122.13.96.0/19122.13.96.1 to 122.13.127.254122.13.127.2558,190
109122.13.128.0/19122.13.128.1 to 122.13.159.254122.13.159.2558,190
110122.13.160.0/19122.13.160.1 to 122.13.191.254122.13.191.2558,190
111122.13.192.0/19122.13.192.1 to 122.13.223.254122.13.223.2558,190
112122.13.224.0/19122.13.224.1 to 122.13.255.254122.13.255.2558,190
113122.14.0.0/19122.14.0.1 to 122.14.31.254122.14.31.2558,190
114122.14.32.0/19122.14.32.1 to 122.14.63.254122.14.63.2558,190
115122.14.64.0/19122.14.64.1 to 122.14.95.254122.14.95.2558,190
116122.14.96.0/19122.14.96.1 to 122.14.127.254122.14.127.2558,190
117122.14.128.0/19122.14.128.1 to 122.14.159.254122.14.159.2558,190
118122.14.160.0/19122.14.160.1 to 122.14.191.254122.14.191.2558,190
119122.14.192.0/19122.14.192.1 to 122.14.223.254122.14.223.2558,190
120122.14.224.0/19122.14.224.1 to 122.14.255.254122.14.255.2558,190
121122.15.0.0/19122.15.0.1 to 122.15.31.254122.15.31.2558,190
122122.15.32.0/19122.15.32.1 to 122.15.63.254122.15.63.2558,190
123122.15.64.0/19122.15.64.1 to 122.15.95.254122.15.95.2558,190
124122.15.96.0/19122.15.96.1 to 122.15.127.254122.15.127.2558,190
125122.15.128.0/19122.15.128.1 to 122.15.159.254122.15.159.2558,190
126122.15.160.0/19122.15.160.1 to 122.15.191.254122.15.191.2558,190
127122.15.192.0/19122.15.192.1 to 122.15.223.254122.15.223.2558,190
128122.15.224.0/19122.15.224.1 to 122.15.255.254122.15.255.2558,190
129122.16.0.0/19122.16.0.1 to 122.16.31.254122.16.31.2558,190
130122.16.32.0/19122.16.32.1 to 122.16.63.254122.16.63.2558,190
131122.16.64.0/19122.16.64.1 to 122.16.95.254122.16.95.2558,190
132122.16.96.0/19122.16.96.1 to 122.16.127.254122.16.127.2558,190
133122.16.128.0/19122.16.128.1 to 122.16.159.254122.16.159.2558,190
134122.16.160.0/19122.16.160.1 to 122.16.191.254122.16.191.2558,190
135122.16.192.0/19122.16.192.1 to 122.16.223.254122.16.223.2558,190
136122.16.224.0/19122.16.224.1 to 122.16.255.254122.16.255.2558,190
137122.17.0.0/19122.17.0.1 to 122.17.31.254122.17.31.2558,190
138122.17.32.0/19122.17.32.1 to 122.17.63.254122.17.63.2558,190
139122.17.64.0/19122.17.64.1 to 122.17.95.254122.17.95.2558,190
140122.17.96.0/19122.17.96.1 to 122.17.127.254122.17.127.2558,190
141122.17.128.0/19122.17.128.1 to 122.17.159.254122.17.159.2558,190
142122.17.160.0/19122.17.160.1 to 122.17.191.254122.17.191.2558,190
143122.17.192.0/19122.17.192.1 to 122.17.223.254122.17.223.2558,190
144122.17.224.0/19122.17.224.1 to 122.17.255.254122.17.255.2558,190
145122.18.0.0/19122.18.0.1 to 122.18.31.254122.18.31.2558,190
146122.18.32.0/19122.18.32.1 to 122.18.63.254122.18.63.2558,190
147122.18.64.0/19122.18.64.1 to 122.18.95.254122.18.95.2558,190
148122.18.96.0/19122.18.96.1 to 122.18.127.254122.18.127.2558,190
149122.18.128.0/19122.18.128.1 to 122.18.159.254122.18.159.2558,190
150122.18.160.0/19122.18.160.1 to 122.18.191.254122.18.191.2558,190
151122.18.192.0/19122.18.192.1 to 122.18.223.254122.18.223.2558,190
152122.18.224.0/19122.18.224.1 to 122.18.255.254122.18.255.2558,190
153122.19.0.0/19122.19.0.1 to 122.19.31.254122.19.31.2558,190
154122.19.32.0/19122.19.32.1 to 122.19.63.254122.19.63.2558,190
155122.19.64.0/19122.19.64.1 to 122.19.95.254122.19.95.2558,190
156122.19.96.0/19122.19.96.1 to 122.19.127.254122.19.127.2558,190
157122.19.128.0/19122.19.128.1 to 122.19.159.254122.19.159.2558,190
158122.19.160.0/19122.19.160.1 to 122.19.191.254122.19.191.2558,190
159122.19.192.0/19122.19.192.1 to 122.19.223.254122.19.223.2558,190
160122.19.224.0/19122.19.224.1 to 122.19.255.254122.19.255.2558,190
161122.20.0.0/19122.20.0.1 to 122.20.31.254122.20.31.2558,190
162122.20.32.0/19122.20.32.1 to 122.20.63.254122.20.63.2558,190
163122.20.64.0/19122.20.64.1 to 122.20.95.254122.20.95.2558,190
164122.20.96.0/19122.20.96.1 to 122.20.127.254122.20.127.2558,190
165122.20.128.0/19122.20.128.1 to 122.20.159.254122.20.159.2558,190
166122.20.160.0/19122.20.160.1 to 122.20.191.254122.20.191.2558,190
167122.20.192.0/19122.20.192.1 to 122.20.223.254122.20.223.2558,190
168122.20.224.0/19122.20.224.1 to 122.20.255.254122.20.255.2558,190
169122.21.0.0/19122.21.0.1 to 122.21.31.254122.21.31.2558,190
170122.21.32.0/19122.21.32.1 to 122.21.63.254122.21.63.2558,190
171122.21.64.0/19122.21.64.1 to 122.21.95.254122.21.95.2558,190
172122.21.96.0/19122.21.96.1 to 122.21.127.254122.21.127.2558,190
173122.21.128.0/19122.21.128.1 to 122.21.159.254122.21.159.2558,190
174122.21.160.0/19122.21.160.1 to 122.21.191.254122.21.191.2558,190
175122.21.192.0/19122.21.192.1 to 122.21.223.254122.21.223.2558,190
176122.21.224.0/19122.21.224.1 to 122.21.255.254122.21.255.2558,190
177122.22.0.0/19122.22.0.1 to 122.22.31.254122.22.31.2558,190
178122.22.32.0/19122.22.32.1 to 122.22.63.254122.22.63.2558,190
179122.22.64.0/19122.22.64.1 to 122.22.95.254122.22.95.2558,190
180122.22.96.0/19122.22.96.1 to 122.22.127.254122.22.127.2558,190
181122.22.128.0/19122.22.128.1 to 122.22.159.254122.22.159.2558,190
182122.22.160.0/19122.22.160.1 to 122.22.191.254122.22.191.2558,190
183122.22.192.0/19122.22.192.1 to 122.22.223.254122.22.223.2558,190
184122.22.224.0/19122.22.224.1 to 122.22.255.254122.22.255.2558,190
185122.23.0.0/19122.23.0.1 to 122.23.31.254122.23.31.2558,190
186122.23.32.0/19122.23.32.1 to 122.23.63.254122.23.63.2558,190
187122.23.64.0/19122.23.64.1 to 122.23.95.254122.23.95.2558,190
188122.23.96.0/19122.23.96.1 to 122.23.127.254122.23.127.2558,190
189122.23.128.0/19122.23.128.1 to 122.23.159.254122.23.159.2558,190
190122.23.160.0/19122.23.160.1 to 122.23.191.254122.23.191.2558,190
191122.23.192.0/19122.23.192.1 to 122.23.223.254122.23.223.2558,190
192122.23.224.0/19122.23.224.1 to 122.23.255.254122.23.255.2558,190
193122.24.0.0/19122.24.0.1 to 122.24.31.254122.24.31.2558,190
194122.24.32.0/19122.24.32.1 to 122.24.63.254122.24.63.2558,190
195122.24.64.0/19122.24.64.1 to 122.24.95.254122.24.95.2558,190
196122.24.96.0/19122.24.96.1 to 122.24.127.254122.24.127.2558,190
197122.24.128.0/19122.24.128.1 to 122.24.159.254122.24.159.2558,190
198122.24.160.0/19122.24.160.1 to 122.24.191.254122.24.191.2558,190
199122.24.192.0/19122.24.192.1 to 122.24.223.254122.24.223.2558,190
200122.24.224.0/19122.24.224.1 to 122.24.255.254122.24.255.2558,190
201122.25.0.0/19122.25.0.1 to 122.25.31.254122.25.31.2558,190
202122.25.32.0/19122.25.32.1 to 122.25.63.254122.25.63.2558,190
203122.25.64.0/19122.25.64.1 to 122.25.95.254122.25.95.2558,190
204122.25.96.0/19122.25.96.1 to 122.25.127.254122.25.127.2558,190
205122.25.128.0/19122.25.128.1 to 122.25.159.254122.25.159.2558,190
206122.25.160.0/19122.25.160.1 to 122.25.191.254122.25.191.2558,190
207122.25.192.0/19122.25.192.1 to 122.25.223.254122.25.223.2558,190
208122.25.224.0/19122.25.224.1 to 122.25.255.254122.25.255.2558,190
209122.26.0.0/19122.26.0.1 to 122.26.31.254122.26.31.2558,190
210122.26.32.0/19122.26.32.1 to 122.26.63.254122.26.63.2558,190
211122.26.64.0/19122.26.64.1 to 122.26.95.254122.26.95.2558,190
212122.26.96.0/19122.26.96.1 to 122.26.127.254122.26.127.2558,190
213122.26.128.0/19122.26.128.1 to 122.26.159.254122.26.159.2558,190
214122.26.160.0/19122.26.160.1 to 122.26.191.254122.26.191.2558,190
215122.26.192.0/19122.26.192.1 to 122.26.223.254122.26.223.2558,190
216122.26.224.0/19122.26.224.1 to 122.26.255.254122.26.255.2558,190
217122.27.0.0/19122.27.0.1 to 122.27.31.254122.27.31.2558,190
218122.27.32.0/19122.27.32.1 to 122.27.63.254122.27.63.2558,190
219122.27.64.0/19122.27.64.1 to 122.27.95.254122.27.95.2558,190
220122.27.96.0/19122.27.96.1 to 122.27.127.254122.27.127.2558,190
221122.27.128.0/19122.27.128.1 to 122.27.159.254122.27.159.2558,190
222122.27.160.0/19122.27.160.1 to 122.27.191.254122.27.191.2558,190
223122.27.192.0/19122.27.192.1 to 122.27.223.254122.27.223.2558,190
224122.27.224.0/19122.27.224.1 to 122.27.255.254122.27.255.2558,190
225122.28.0.0/19122.28.0.1 to 122.28.31.254122.28.31.2558,190
226122.28.32.0/19122.28.32.1 to 122.28.63.254122.28.63.2558,190
227122.28.64.0/19122.28.64.1 to 122.28.95.254122.28.95.2558,190
228122.28.96.0/19122.28.96.1 to 122.28.127.254122.28.127.2558,190
229122.28.128.0/19122.28.128.1 to 122.28.159.254122.28.159.2558,190
230122.28.160.0/19122.28.160.1 to 122.28.191.254122.28.191.2558,190
231122.28.192.0/19122.28.192.1 to 122.28.223.254122.28.223.2558,190
232122.28.224.0/19122.28.224.1 to 122.28.255.254122.28.255.2558,190
233122.29.0.0/19122.29.0.1 to 122.29.31.254122.29.31.2558,190
234122.29.32.0/19122.29.32.1 to 122.29.63.254122.29.63.2558,190
235122.29.64.0/19122.29.64.1 to 122.29.95.254122.29.95.2558,190
236122.29.96.0/19122.29.96.1 to 122.29.127.254122.29.127.2558,190
237122.29.128.0/19122.29.128.1 to 122.29.159.254122.29.159.2558,190
238122.29.160.0/19122.29.160.1 to 122.29.191.254122.29.191.2558,190
239122.29.192.0/19122.29.192.1 to 122.29.223.254122.29.223.2558,190
240122.29.224.0/19122.29.224.1 to 122.29.255.254122.29.255.2558,190
241122.30.0.0/19122.30.0.1 to 122.30.31.254122.30.31.2558,190
242122.30.32.0/19122.30.32.1 to 122.30.63.254122.30.63.2558,190
243122.30.64.0/19122.30.64.1 to 122.30.95.254122.30.95.2558,190
244122.30.96.0/19122.30.96.1 to 122.30.127.254122.30.127.2558,190
245122.30.128.0/19122.30.128.1 to 122.30.159.254122.30.159.2558,190
246122.30.160.0/19122.30.160.1 to 122.30.191.254122.30.191.2558,190
247122.30.192.0/19122.30.192.1 to 122.30.223.254122.30.223.2558,190
248122.30.224.0/19122.30.224.1 to 122.30.255.254122.30.255.2558,190
249122.31.0.0/19122.31.0.1 to 122.31.31.254122.31.31.2558,190
250122.31.32.0/19122.31.32.1 to 122.31.63.254122.31.63.2558,190
251122.31.64.0/19122.31.64.1 to 122.31.95.254122.31.95.2558,190
252122.31.96.0/19122.31.96.1 to 122.31.127.254122.31.127.2558,190
253122.31.128.0/19122.31.128.1 to 122.31.159.254122.31.159.2558,190
254122.31.160.0/19122.31.160.1 to 122.31.191.254122.31.191.2558,190
255122.31.192.0/19122.31.192.1 to 122.31.223.254122.31.223.2558,190
256122.31.224.0/19122.31.224.1 to 122.31.255.254122.31.255.2558,190

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.