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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.

Network122.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
122.0.0.0
Broadcast address
122.255.255.255
First usable
122.0.0.1
Last usable
122.255.255.254
Usable hosts
16,777,214 (16,777,216 less the network and broadcast addresses)
Subnet mask
255.0.0.0
Wildcard mask
0.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/8
Type
Public public
Old class
A (default /8)
As numbers
Hex 7A000000 · Integer 2046820352 to 2063597567
Reverse DNS zone
122.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01111010..00000000.00000000.00000000122.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network01111010..00000000.00000000.00000000122.0.0.0
Broadcast01111010..11111111.11111111.11111111122.255.255.255
Split into smaller subnets/18
/9 (2)/10 (4)/11 (8)/12 (16)/13 (32)/14 (64)/15 (128)/16 (256)/17 (512)/18 (1,024)/19 (2,048)/20 (4,096)

122.0.0.0/8 makes 1,024 subnets of /18; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1122.0.0.0/18122.0.0.1 to 122.0.63.254122.0.63.25516,382
2122.0.64.0/18122.0.64.1 to 122.0.127.254122.0.127.25516,382
3122.0.128.0/18122.0.128.1 to 122.0.191.254122.0.191.25516,382
4122.0.192.0/18122.0.192.1 to 122.0.255.254122.0.255.25516,382
5122.1.0.0/18122.1.0.1 to 122.1.63.254122.1.63.25516,382
6122.1.64.0/18122.1.64.1 to 122.1.127.254122.1.127.25516,382
7122.1.128.0/18122.1.128.1 to 122.1.191.254122.1.191.25516,382
8122.1.192.0/18122.1.192.1 to 122.1.255.254122.1.255.25516,382
9122.2.0.0/18122.2.0.1 to 122.2.63.254122.2.63.25516,382
10122.2.64.0/18122.2.64.1 to 122.2.127.254122.2.127.25516,382
11122.2.128.0/18122.2.128.1 to 122.2.191.254122.2.191.25516,382
12122.2.192.0/18122.2.192.1 to 122.2.255.254122.2.255.25516,382
13122.3.0.0/18122.3.0.1 to 122.3.63.254122.3.63.25516,382
14122.3.64.0/18122.3.64.1 to 122.3.127.254122.3.127.25516,382
15122.3.128.0/18122.3.128.1 to 122.3.191.254122.3.191.25516,382
16122.3.192.0/18122.3.192.1 to 122.3.255.254122.3.255.25516,382
17122.4.0.0/18122.4.0.1 to 122.4.63.254122.4.63.25516,382
18122.4.64.0/18122.4.64.1 to 122.4.127.254122.4.127.25516,382
19122.4.128.0/18122.4.128.1 to 122.4.191.254122.4.191.25516,382
20122.4.192.0/18122.4.192.1 to 122.4.255.254122.4.255.25516,382
21122.5.0.0/18122.5.0.1 to 122.5.63.254122.5.63.25516,382
22122.5.64.0/18122.5.64.1 to 122.5.127.254122.5.127.25516,382
23122.5.128.0/18122.5.128.1 to 122.5.191.254122.5.191.25516,382
24122.5.192.0/18122.5.192.1 to 122.5.255.254122.5.255.25516,382
25122.6.0.0/18122.6.0.1 to 122.6.63.254122.6.63.25516,382
26122.6.64.0/18122.6.64.1 to 122.6.127.254122.6.127.25516,382
27122.6.128.0/18122.6.128.1 to 122.6.191.254122.6.191.25516,382
28122.6.192.0/18122.6.192.1 to 122.6.255.254122.6.255.25516,382
29122.7.0.0/18122.7.0.1 to 122.7.63.254122.7.63.25516,382
30122.7.64.0/18122.7.64.1 to 122.7.127.254122.7.127.25516,382
31122.7.128.0/18122.7.128.1 to 122.7.191.254122.7.191.25516,382
32122.7.192.0/18122.7.192.1 to 122.7.255.254122.7.255.25516,382
33122.8.0.0/18122.8.0.1 to 122.8.63.254122.8.63.25516,382
34122.8.64.0/18122.8.64.1 to 122.8.127.254122.8.127.25516,382
35122.8.128.0/18122.8.128.1 to 122.8.191.254122.8.191.25516,382
36122.8.192.0/18122.8.192.1 to 122.8.255.254122.8.255.25516,382
37122.9.0.0/18122.9.0.1 to 122.9.63.254122.9.63.25516,382
38122.9.64.0/18122.9.64.1 to 122.9.127.254122.9.127.25516,382
39122.9.128.0/18122.9.128.1 to 122.9.191.254122.9.191.25516,382
40122.9.192.0/18122.9.192.1 to 122.9.255.254122.9.255.25516,382
41122.10.0.0/18122.10.0.1 to 122.10.63.254122.10.63.25516,382
42122.10.64.0/18122.10.64.1 to 122.10.127.254122.10.127.25516,382
43122.10.128.0/18122.10.128.1 to 122.10.191.254122.10.191.25516,382
44122.10.192.0/18122.10.192.1 to 122.10.255.254122.10.255.25516,382
45122.11.0.0/18122.11.0.1 to 122.11.63.254122.11.63.25516,382
46122.11.64.0/18122.11.64.1 to 122.11.127.254122.11.127.25516,382
47122.11.128.0/18122.11.128.1 to 122.11.191.254122.11.191.25516,382
48122.11.192.0/18122.11.192.1 to 122.11.255.254122.11.255.25516,382
49122.12.0.0/18122.12.0.1 to 122.12.63.254122.12.63.25516,382
50122.12.64.0/18122.12.64.1 to 122.12.127.254122.12.127.25516,382
51122.12.128.0/18122.12.128.1 to 122.12.191.254122.12.191.25516,382
52122.12.192.0/18122.12.192.1 to 122.12.255.254122.12.255.25516,382
53122.13.0.0/18122.13.0.1 to 122.13.63.254122.13.63.25516,382
54122.13.64.0/18122.13.64.1 to 122.13.127.254122.13.127.25516,382
55122.13.128.0/18122.13.128.1 to 122.13.191.254122.13.191.25516,382
56122.13.192.0/18122.13.192.1 to 122.13.255.254122.13.255.25516,382
57122.14.0.0/18122.14.0.1 to 122.14.63.254122.14.63.25516,382
58122.14.64.0/18122.14.64.1 to 122.14.127.254122.14.127.25516,382
59122.14.128.0/18122.14.128.1 to 122.14.191.254122.14.191.25516,382
60122.14.192.0/18122.14.192.1 to 122.14.255.254122.14.255.25516,382
61122.15.0.0/18122.15.0.1 to 122.15.63.254122.15.63.25516,382
62122.15.64.0/18122.15.64.1 to 122.15.127.254122.15.127.25516,382
63122.15.128.0/18122.15.128.1 to 122.15.191.254122.15.191.25516,382
64122.15.192.0/18122.15.192.1 to 122.15.255.254122.15.255.25516,382
65122.16.0.0/18122.16.0.1 to 122.16.63.254122.16.63.25516,382
66122.16.64.0/18122.16.64.1 to 122.16.127.254122.16.127.25516,382
67122.16.128.0/18122.16.128.1 to 122.16.191.254122.16.191.25516,382
68122.16.192.0/18122.16.192.1 to 122.16.255.254122.16.255.25516,382
69122.17.0.0/18122.17.0.1 to 122.17.63.254122.17.63.25516,382
70122.17.64.0/18122.17.64.1 to 122.17.127.254122.17.127.25516,382
71122.17.128.0/18122.17.128.1 to 122.17.191.254122.17.191.25516,382
72122.17.192.0/18122.17.192.1 to 122.17.255.254122.17.255.25516,382
73122.18.0.0/18122.18.0.1 to 122.18.63.254122.18.63.25516,382
74122.18.64.0/18122.18.64.1 to 122.18.127.254122.18.127.25516,382
75122.18.128.0/18122.18.128.1 to 122.18.191.254122.18.191.25516,382
76122.18.192.0/18122.18.192.1 to 122.18.255.254122.18.255.25516,382
77122.19.0.0/18122.19.0.1 to 122.19.63.254122.19.63.25516,382
78122.19.64.0/18122.19.64.1 to 122.19.127.254122.19.127.25516,382
79122.19.128.0/18122.19.128.1 to 122.19.191.254122.19.191.25516,382
80122.19.192.0/18122.19.192.1 to 122.19.255.254122.19.255.25516,382
81122.20.0.0/18122.20.0.1 to 122.20.63.254122.20.63.25516,382
82122.20.64.0/18122.20.64.1 to 122.20.127.254122.20.127.25516,382
83122.20.128.0/18122.20.128.1 to 122.20.191.254122.20.191.25516,382
84122.20.192.0/18122.20.192.1 to 122.20.255.254122.20.255.25516,382
85122.21.0.0/18122.21.0.1 to 122.21.63.254122.21.63.25516,382
86122.21.64.0/18122.21.64.1 to 122.21.127.254122.21.127.25516,382
87122.21.128.0/18122.21.128.1 to 122.21.191.254122.21.191.25516,382
88122.21.192.0/18122.21.192.1 to 122.21.255.254122.21.255.25516,382
89122.22.0.0/18122.22.0.1 to 122.22.63.254122.22.63.25516,382
90122.22.64.0/18122.22.64.1 to 122.22.127.254122.22.127.25516,382
91122.22.128.0/18122.22.128.1 to 122.22.191.254122.22.191.25516,382
92122.22.192.0/18122.22.192.1 to 122.22.255.254122.22.255.25516,382
93122.23.0.0/18122.23.0.1 to 122.23.63.254122.23.63.25516,382
94122.23.64.0/18122.23.64.1 to 122.23.127.254122.23.127.25516,382
95122.23.128.0/18122.23.128.1 to 122.23.191.254122.23.191.25516,382
96122.23.192.0/18122.23.192.1 to 122.23.255.254122.23.255.25516,382
97122.24.0.0/18122.24.0.1 to 122.24.63.254122.24.63.25516,382
98122.24.64.0/18122.24.64.1 to 122.24.127.254122.24.127.25516,382
99122.24.128.0/18122.24.128.1 to 122.24.191.254122.24.191.25516,382
100122.24.192.0/18122.24.192.1 to 122.24.255.254122.24.255.25516,382
101122.25.0.0/18122.25.0.1 to 122.25.63.254122.25.63.25516,382
102122.25.64.0/18122.25.64.1 to 122.25.127.254122.25.127.25516,382
103122.25.128.0/18122.25.128.1 to 122.25.191.254122.25.191.25516,382
104122.25.192.0/18122.25.192.1 to 122.25.255.254122.25.255.25516,382
105122.26.0.0/18122.26.0.1 to 122.26.63.254122.26.63.25516,382
106122.26.64.0/18122.26.64.1 to 122.26.127.254122.26.127.25516,382
107122.26.128.0/18122.26.128.1 to 122.26.191.254122.26.191.25516,382
108122.26.192.0/18122.26.192.1 to 122.26.255.254122.26.255.25516,382
109122.27.0.0/18122.27.0.1 to 122.27.63.254122.27.63.25516,382
110122.27.64.0/18122.27.64.1 to 122.27.127.254122.27.127.25516,382
111122.27.128.0/18122.27.128.1 to 122.27.191.254122.27.191.25516,382
112122.27.192.0/18122.27.192.1 to 122.27.255.254122.27.255.25516,382
113122.28.0.0/18122.28.0.1 to 122.28.63.254122.28.63.25516,382
114122.28.64.0/18122.28.64.1 to 122.28.127.254122.28.127.25516,382
115122.28.128.0/18122.28.128.1 to 122.28.191.254122.28.191.25516,382
116122.28.192.0/18122.28.192.1 to 122.28.255.254122.28.255.25516,382
117122.29.0.0/18122.29.0.1 to 122.29.63.254122.29.63.25516,382
118122.29.64.0/18122.29.64.1 to 122.29.127.254122.29.127.25516,382
119122.29.128.0/18122.29.128.1 to 122.29.191.254122.29.191.25516,382
120122.29.192.0/18122.29.192.1 to 122.29.255.254122.29.255.25516,382
121122.30.0.0/18122.30.0.1 to 122.30.63.254122.30.63.25516,382
122122.30.64.0/18122.30.64.1 to 122.30.127.254122.30.127.25516,382
123122.30.128.0/18122.30.128.1 to 122.30.191.254122.30.191.25516,382
124122.30.192.0/18122.30.192.1 to 122.30.255.254122.30.255.25516,382
125122.31.0.0/18122.31.0.1 to 122.31.63.254122.31.63.25516,382
126122.31.64.0/18122.31.64.1 to 122.31.127.254122.31.127.25516,382
127122.31.128.0/18122.31.128.1 to 122.31.191.254122.31.191.25516,382
128122.31.192.0/18122.31.192.1 to 122.31.255.254122.31.255.25516,382
129122.32.0.0/18122.32.0.1 to 122.32.63.254122.32.63.25516,382
130122.32.64.0/18122.32.64.1 to 122.32.127.254122.32.127.25516,382
131122.32.128.0/18122.32.128.1 to 122.32.191.254122.32.191.25516,382
132122.32.192.0/18122.32.192.1 to 122.32.255.254122.32.255.25516,382
133122.33.0.0/18122.33.0.1 to 122.33.63.254122.33.63.25516,382
134122.33.64.0/18122.33.64.1 to 122.33.127.254122.33.127.25516,382
135122.33.128.0/18122.33.128.1 to 122.33.191.254122.33.191.25516,382
136122.33.192.0/18122.33.192.1 to 122.33.255.254122.33.255.25516,382
137122.34.0.0/18122.34.0.1 to 122.34.63.254122.34.63.25516,382
138122.34.64.0/18122.34.64.1 to 122.34.127.254122.34.127.25516,382
139122.34.128.0/18122.34.128.1 to 122.34.191.254122.34.191.25516,382
140122.34.192.0/18122.34.192.1 to 122.34.255.254122.34.255.25516,382
141122.35.0.0/18122.35.0.1 to 122.35.63.254122.35.63.25516,382
142122.35.64.0/18122.35.64.1 to 122.35.127.254122.35.127.25516,382
143122.35.128.0/18122.35.128.1 to 122.35.191.254122.35.191.25516,382
144122.35.192.0/18122.35.192.1 to 122.35.255.254122.35.255.25516,382
145122.36.0.0/18122.36.0.1 to 122.36.63.254122.36.63.25516,382
146122.36.64.0/18122.36.64.1 to 122.36.127.254122.36.127.25516,382
147122.36.128.0/18122.36.128.1 to 122.36.191.254122.36.191.25516,382
148122.36.192.0/18122.36.192.1 to 122.36.255.254122.36.255.25516,382
149122.37.0.0/18122.37.0.1 to 122.37.63.254122.37.63.25516,382
150122.37.64.0/18122.37.64.1 to 122.37.127.254122.37.127.25516,382
151122.37.128.0/18122.37.128.1 to 122.37.191.254122.37.191.25516,382
152122.37.192.0/18122.37.192.1 to 122.37.255.254122.37.255.25516,382
153122.38.0.0/18122.38.0.1 to 122.38.63.254122.38.63.25516,382
154122.38.64.0/18122.38.64.1 to 122.38.127.254122.38.127.25516,382
155122.38.128.0/18122.38.128.1 to 122.38.191.254122.38.191.25516,382
156122.38.192.0/18122.38.192.1 to 122.38.255.254122.38.255.25516,382
157122.39.0.0/18122.39.0.1 to 122.39.63.254122.39.63.25516,382
158122.39.64.0/18122.39.64.1 to 122.39.127.254122.39.127.25516,382
159122.39.128.0/18122.39.128.1 to 122.39.191.254122.39.191.25516,382
160122.39.192.0/18122.39.192.1 to 122.39.255.254122.39.255.25516,382
161122.40.0.0/18122.40.0.1 to 122.40.63.254122.40.63.25516,382
162122.40.64.0/18122.40.64.1 to 122.40.127.254122.40.127.25516,382
163122.40.128.0/18122.40.128.1 to 122.40.191.254122.40.191.25516,382
164122.40.192.0/18122.40.192.1 to 122.40.255.254122.40.255.25516,382
165122.41.0.0/18122.41.0.1 to 122.41.63.254122.41.63.25516,382
166122.41.64.0/18122.41.64.1 to 122.41.127.254122.41.127.25516,382
167122.41.128.0/18122.41.128.1 to 122.41.191.254122.41.191.25516,382
168122.41.192.0/18122.41.192.1 to 122.41.255.254122.41.255.25516,382
169122.42.0.0/18122.42.0.1 to 122.42.63.254122.42.63.25516,382
170122.42.64.0/18122.42.64.1 to 122.42.127.254122.42.127.25516,382
171122.42.128.0/18122.42.128.1 to 122.42.191.254122.42.191.25516,382
172122.42.192.0/18122.42.192.1 to 122.42.255.254122.42.255.25516,382
173122.43.0.0/18122.43.0.1 to 122.43.63.254122.43.63.25516,382
174122.43.64.0/18122.43.64.1 to 122.43.127.254122.43.127.25516,382
175122.43.128.0/18122.43.128.1 to 122.43.191.254122.43.191.25516,382
176122.43.192.0/18122.43.192.1 to 122.43.255.254122.43.255.25516,382
177122.44.0.0/18122.44.0.1 to 122.44.63.254122.44.63.25516,382
178122.44.64.0/18122.44.64.1 to 122.44.127.254122.44.127.25516,382
179122.44.128.0/18122.44.128.1 to 122.44.191.254122.44.191.25516,382
180122.44.192.0/18122.44.192.1 to 122.44.255.254122.44.255.25516,382
181122.45.0.0/18122.45.0.1 to 122.45.63.254122.45.63.25516,382
182122.45.64.0/18122.45.64.1 to 122.45.127.254122.45.127.25516,382
183122.45.128.0/18122.45.128.1 to 122.45.191.254122.45.191.25516,382
184122.45.192.0/18122.45.192.1 to 122.45.255.254122.45.255.25516,382
185122.46.0.0/18122.46.0.1 to 122.46.63.254122.46.63.25516,382
186122.46.64.0/18122.46.64.1 to 122.46.127.254122.46.127.25516,382
187122.46.128.0/18122.46.128.1 to 122.46.191.254122.46.191.25516,382
188122.46.192.0/18122.46.192.1 to 122.46.255.254122.46.255.25516,382
189122.47.0.0/18122.47.0.1 to 122.47.63.254122.47.63.25516,382
190122.47.64.0/18122.47.64.1 to 122.47.127.254122.47.127.25516,382
191122.47.128.0/18122.47.128.1 to 122.47.191.254122.47.191.25516,382
192122.47.192.0/18122.47.192.1 to 122.47.255.254122.47.255.25516,382
193122.48.0.0/18122.48.0.1 to 122.48.63.254122.48.63.25516,382
194122.48.64.0/18122.48.64.1 to 122.48.127.254122.48.127.25516,382
195122.48.128.0/18122.48.128.1 to 122.48.191.254122.48.191.25516,382
196122.48.192.0/18122.48.192.1 to 122.48.255.254122.48.255.25516,382
197122.49.0.0/18122.49.0.1 to 122.49.63.254122.49.63.25516,382
198122.49.64.0/18122.49.64.1 to 122.49.127.254122.49.127.25516,382
199122.49.128.0/18122.49.128.1 to 122.49.191.254122.49.191.25516,382
200122.49.192.0/18122.49.192.1 to 122.49.255.254122.49.255.25516,382
201122.50.0.0/18122.50.0.1 to 122.50.63.254122.50.63.25516,382
202122.50.64.0/18122.50.64.1 to 122.50.127.254122.50.127.25516,382
203122.50.128.0/18122.50.128.1 to 122.50.191.254122.50.191.25516,382
204122.50.192.0/18122.50.192.1 to 122.50.255.254122.50.255.25516,382
205122.51.0.0/18122.51.0.1 to 122.51.63.254122.51.63.25516,382
206122.51.64.0/18122.51.64.1 to 122.51.127.254122.51.127.25516,382
207122.51.128.0/18122.51.128.1 to 122.51.191.254122.51.191.25516,382
208122.51.192.0/18122.51.192.1 to 122.51.255.254122.51.255.25516,382
209122.52.0.0/18122.52.0.1 to 122.52.63.254122.52.63.25516,382
210122.52.64.0/18122.52.64.1 to 122.52.127.254122.52.127.25516,382
211122.52.128.0/18122.52.128.1 to 122.52.191.254122.52.191.25516,382
212122.52.192.0/18122.52.192.1 to 122.52.255.254122.52.255.25516,382
213122.53.0.0/18122.53.0.1 to 122.53.63.254122.53.63.25516,382
214122.53.64.0/18122.53.64.1 to 122.53.127.254122.53.127.25516,382
215122.53.128.0/18122.53.128.1 to 122.53.191.254122.53.191.25516,382
216122.53.192.0/18122.53.192.1 to 122.53.255.254122.53.255.25516,382
217122.54.0.0/18122.54.0.1 to 122.54.63.254122.54.63.25516,382
218122.54.64.0/18122.54.64.1 to 122.54.127.254122.54.127.25516,382
219122.54.128.0/18122.54.128.1 to 122.54.191.254122.54.191.25516,382
220122.54.192.0/18122.54.192.1 to 122.54.255.254122.54.255.25516,382
221122.55.0.0/18122.55.0.1 to 122.55.63.254122.55.63.25516,382
222122.55.64.0/18122.55.64.1 to 122.55.127.254122.55.127.25516,382
223122.55.128.0/18122.55.128.1 to 122.55.191.254122.55.191.25516,382
224122.55.192.0/18122.55.192.1 to 122.55.255.254122.55.255.25516,382
225122.56.0.0/18122.56.0.1 to 122.56.63.254122.56.63.25516,382
226122.56.64.0/18122.56.64.1 to 122.56.127.254122.56.127.25516,382
227122.56.128.0/18122.56.128.1 to 122.56.191.254122.56.191.25516,382
228122.56.192.0/18122.56.192.1 to 122.56.255.254122.56.255.25516,382
229122.57.0.0/18122.57.0.1 to 122.57.63.254122.57.63.25516,382
230122.57.64.0/18122.57.64.1 to 122.57.127.254122.57.127.25516,382
231122.57.128.0/18122.57.128.1 to 122.57.191.254122.57.191.25516,382
232122.57.192.0/18122.57.192.1 to 122.57.255.254122.57.255.25516,382
233122.58.0.0/18122.58.0.1 to 122.58.63.254122.58.63.25516,382
234122.58.64.0/18122.58.64.1 to 122.58.127.254122.58.127.25516,382
235122.58.128.0/18122.58.128.1 to 122.58.191.254122.58.191.25516,382
236122.58.192.0/18122.58.192.1 to 122.58.255.254122.58.255.25516,382
237122.59.0.0/18122.59.0.1 to 122.59.63.254122.59.63.25516,382
238122.59.64.0/18122.59.64.1 to 122.59.127.254122.59.127.25516,382
239122.59.128.0/18122.59.128.1 to 122.59.191.254122.59.191.25516,382
240122.59.192.0/18122.59.192.1 to 122.59.255.254122.59.255.25516,382
241122.60.0.0/18122.60.0.1 to 122.60.63.254122.60.63.25516,382
242122.60.64.0/18122.60.64.1 to 122.60.127.254122.60.127.25516,382
243122.60.128.0/18122.60.128.1 to 122.60.191.254122.60.191.25516,382
244122.60.192.0/18122.60.192.1 to 122.60.255.254122.60.255.25516,382
245122.61.0.0/18122.61.0.1 to 122.61.63.254122.61.63.25516,382
246122.61.64.0/18122.61.64.1 to 122.61.127.254122.61.127.25516,382
247122.61.128.0/18122.61.128.1 to 122.61.191.254122.61.191.25516,382
248122.61.192.0/18122.61.192.1 to 122.61.255.254122.61.255.25516,382
249122.62.0.0/18122.62.0.1 to 122.62.63.254122.62.63.25516,382
250122.62.64.0/18122.62.64.1 to 122.62.127.254122.62.127.25516,382
251122.62.128.0/18122.62.128.1 to 122.62.191.254122.62.191.25516,382
252122.62.192.0/18122.62.192.1 to 122.62.255.254122.62.255.25516,382
253122.63.0.0/18122.63.0.1 to 122.63.63.254122.63.63.25516,382
254122.63.64.0/18122.63.64.1 to 122.63.127.254122.63.127.25516,382
255122.63.128.0/18122.63.128.1 to 122.63.191.254122.63.191.25516,382
256122.63.192.0/18122.63.192.1 to 122.63.255.254122.63.255.25516,382

IPv4 CIDR reference (/0 to /32)

IPv4 prefix lengths
PrefixSubnet maskWildcardAddressesUsable hostsSizeTypical use
/00.0.0.0255.255.255.2554,294,967,2964,294,967,29416,777,216 × /24
/1128.0.0.0127.255.255.2552,147,483,6482,147,483,6468,388,608 × /24
/2192.0.0.063.255.255.2551,073,741,8241,073,741,8224,194,304 × /24
/3224.0.0.031.255.255.255536,870,912536,870,9102,097,152 × /24
/4240.0.0.015.255.255.255268,435,456268,435,4541,048,576 × /24
/5248.0.0.07.255.255.255134,217,728134,217,726524,288 × /24
/6252.0.0.03.255.255.25567,108,86467,108,862262,144 × /24
/7254.0.0.01.255.255.25533,554,43233,554,430131,072 × /24
/8255.0.0.00.255.255.25516,777,21616,777,21465,536 × /24Old class A; 10.0.0.0/8
/9255.128.0.00.127.255.2558,388,6088,388,60632,768 × /24
/10255.192.0.00.63.255.2554,194,3044,194,30216,384 × /24
/11255.224.0.00.31.255.2552,097,1522,097,1508,192 × /24
/12255.240.0.00.15.255.2551,048,5761,048,5744,096 × /24172.16.0.0/12
/13255.248.0.00.7.255.255524,288524,2862,048 × /24
/14255.252.0.00.3.255.255262,144262,1421,024 × /24
/15255.254.0.00.1.255.255131,072131,070512 × /24
/16255.255.0.00.0.255.25565,53665,534256 × /24Old class B; 192.168.0.0/16
/17255.255.128.00.0.127.25532,76832,766128 × /24
/18255.255.192.00.0.63.25516,38416,38264 × /24
/19255.255.224.00.0.31.2558,1928,19032 × /24
/20255.255.240.00.0.15.2554,0964,09416 × /24
/21255.255.248.00.0.7.2552,0482,0468 × /24
/22255.255.252.00.0.3.2551,0241,0224 × /24Large office or guest Wi-Fi (1,022 hosts)
/23255.255.254.00.0.1.2555125102 × /24Larger office LAN (510 hosts)
/24255.255.255.00.0.0.2552562541 × /24Typical office LAN (old class C)
/25255.255.255.1280.0.0.1271281261/2 of a /24Smaller LAN or VLAN
/26255.255.255.1920.0.0.6364621/4 of a /24Smaller LAN or VLAN
/27255.255.255.2240.0.0.3132301/8 of a /24Small VLAN, phones, cameras
/28255.255.255.2400.0.0.1516141/16 of a /24Small VLAN, phones, cameras
/29255.255.255.2480.0.0.7861/32 of a /24Small fixed public block (5 usable)
/30255.255.255.2520.0.0.3421/64 of a /24Point-to-point (old style)
/31255.255.255.2540.0.0.1221/128 of a /24Point-to-point link (RFC 3021)
/32255.255.255.2550.0.0.0111/256 of a /24One host

IPv6 prefix reference

IPv6 prefix lengths
PrefixAddresses/64 LANs/48 sitesNibbleTypical use
/342,535,295,865,117,307,932,921,825,928,971,026,432 (2^125)2,305,843,009,213,693,95235,184,372,088,832NoAll global unicast (2000::/3)
/165,192,296,858,534,827,628,530,496,329,220,096 (2^112)281,474,976,710,6564,294,967,296Yes
/20324,518,553,658,426,726,783,156,020,576,256 (2^108)17,592,186,044,416268,435,456YesLarge provider allocation (RIPE minimum for some)
/29633,825,300,114,114,700,748,351,602,688 (2^99)34,359,738,368524,288NoRIPE allocation to a provider (often)
/3279,228,162,514,264,337,593,543,950,336 (2^96)4,294,967,29665,536YesProvider allocation (RIPE default)
/364,951,760,157,141,521,099,596,496,896 (2^92)268,435,4564,096Yes
/40309,485,009,821,345,068,724,781,056 (2^88)16,777,216256Yes
/4419,342,813,113,834,066,795,298,816 (2^84)1,048,57616Yes
/481,208,925,819,614,629,174,706,176 (2^80)65,5361YesOne site or organisation (RIPE PI / assignment)
/5275,557,863,725,914,323,419,136 (2^76)4,096Yes
/564,722,366,482,869,645,213,696 (2^72)256YesSmall site or home (common provider assignment)
/60295,147,905,179,352,825,856 (2^68)16YesSome home broadband (16 LANs)
/6418,446,744,073,709,551,616 (2^64)1YesOne LAN or VLAN (needed for SLAAC)
/7272,057,594,037,927,936 (2^56)1/256 of a /64Yes
/80281,474,976,710,656 (2^48)1/65,536 of a /64Yes
/964,294,967,2961/4,294,967,296 of a /64YesEmbeds an IPv4 address (NAT64)
/11265,5361/281,474,976,710,656 of a /64Yes
/1202561/72,057,594,037,927,936 of a /64Yes
/124161/1,152,921,504,606,846,976 of a /64Yes
/12641/4,611,686,018,427,387,904 of a /64No
/12721/9,223,372,036,854,775,808 of a /64NoPoint-to-point link (RFC 6164)
/12811/18,446,744,073,709,551,616 of a /64YesOne host or loopback

Private and special ranges

IPv4

Special-purpose ranges
RangeNameWhat it is
255.255.255.255/32Limited broadcastEvery host on the local network
0.0.0.0/8This networkNot routed; 0.0.0.0 means "any address" in settings
10.0.0.0/8Private (RFC 1918)Office and home networks; not routed on the internet
100.64.0.0/10Shared address space (CGNAT)Used by providers behind carrier-grade NAT (RFC 6598)
127.0.0.0/8LoopbackThis computer
169.254.0.0/16Link-local (APIPA)Self-assigned when no DHCP server answers
172.16.0.0/12Private (RFC 1918)Office and home networks; not routed on the internet
192.0.0.0/24IETF protocol assignmentsSpecial uses such as DS-Lite
192.0.2.0/24Documentation (TEST-NET-1)For examples; never used on a network
192.88.99.0/246to4 relay (deprecated)Formerly anycast for 6to4
192.168.0.0/16Private (RFC 1918)Office and home networks; not routed on the internet
198.18.0.0/15BenchmarkingNetwork equipment testing (RFC 2544)
198.51.100.0/24Documentation (TEST-NET-2)For examples; never used on a network
203.0.113.0/24Documentation (TEST-NET-3)For examples; never used on a network
224.0.0.0/4MulticastOne-to-many traffic, such as IPTV and routing protocols
240.0.0.0/4ReservedFuture use; not usable on most systems

IPv6

Special-purpose ranges
RangeNameWhat it is
::/128UnspecifiedNo address; :: means "any address" in settings
::1/128LoopbackThis computer
::ffff:0:0/96IPv4-mappedAn IPv4 address written as IPv6
64:ff9b::/96NAT64IPv4 addresses reached through a NAT64 gateway
100::/64Discard onlyTraffic sent here is dropped (RFC 6666)
2001:db8::/32DocumentationFor examples; never used on a network
2001::/32TeredoIPv6 tunnelled over IPv4 UDP
2002::/166to4IPv6 tunnelled over IPv4 (largely retired)
3fff::/20DocumentationFor examples (RFC 9637)
fc00::/7Unique local (ULA)Private IPv6, like RFC 1918; usually fd00::/8
fe80::/10Link-localEvery IPv6 interface has one; not routed
ff00::/8MulticastOne-to-many traffic; replaces broadcast
2000::/3Global unicastPublic internet addresses

About this tool

A network is written as an address and a prefix length, such as 192.168.1.0/24: the first 24 bits name the network and the rest number the devices on it. The calculator works out where the network starts and ends, how many devices it holds, its subnet and wildcard masks, and the reverse DNS zone to ask your provider for.

It also splits a network into equal smaller ones (one per VLAN or site), turns a range of addresses into the fewest CIDR blocks for a firewall rule, and lists every IPv4 prefix length and the common IPv6 ones in reference tables.

Common questions

Why are two addresses lost in every IPv4 subnet?

The first address names the network and the last is the broadcast address, so a /24 has 256 addresses but 254 for devices. A /31 (a link between two routers) and a /32 (one host) are the exceptions.

What size of IPv6 network should a LAN use?

Always /64. Devices pick their own address within it (SLAAC), which needs the full 64 bits. A site usually gets a /48 or /56 from its provider, which holds 65,536 or 256 LANs.

What is a wildcard mask?

The subnet mask turned inside out: 255.255.255.0 becomes 0.0.0.255. Cisco access lists and OSPF use it to say which bits must match.

Which ranges can I use inside an office?

IPv4: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. IPv6: unique local addresses from fd00::/8, though most networks use the public prefix from their provider.