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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.

Network220.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
220.0.0.0
Broadcast address
220.255.255.255
First usable
220.0.0.1
Last usable
220.255.255.254
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
C (default /24)
As numbers
Hex DC000000 · Integer 3690987520 to 3707764735
Reverse DNS zone
220.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11011100..00000000.00000000.00000000220.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network11011100..00000000.00000000.00000000220.0.0.0
Broadcast11011100..11111111.11111111.11111111220.255.255.255
Split into smaller subnets/19
/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)

220.0.0.0/8 makes 2,048 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1220.0.0.0/19220.0.0.1 to 220.0.31.254220.0.31.2558,190
2220.0.32.0/19220.0.32.1 to 220.0.63.254220.0.63.2558,190
3220.0.64.0/19220.0.64.1 to 220.0.95.254220.0.95.2558,190
4220.0.96.0/19220.0.96.1 to 220.0.127.254220.0.127.2558,190
5220.0.128.0/19220.0.128.1 to 220.0.159.254220.0.159.2558,190
6220.0.160.0/19220.0.160.1 to 220.0.191.254220.0.191.2558,190
7220.0.192.0/19220.0.192.1 to 220.0.223.254220.0.223.2558,190
8220.0.224.0/19220.0.224.1 to 220.0.255.254220.0.255.2558,190
9220.1.0.0/19220.1.0.1 to 220.1.31.254220.1.31.2558,190
10220.1.32.0/19220.1.32.1 to 220.1.63.254220.1.63.2558,190
11220.1.64.0/19220.1.64.1 to 220.1.95.254220.1.95.2558,190
12220.1.96.0/19220.1.96.1 to 220.1.127.254220.1.127.2558,190
13220.1.128.0/19220.1.128.1 to 220.1.159.254220.1.159.2558,190
14220.1.160.0/19220.1.160.1 to 220.1.191.254220.1.191.2558,190
15220.1.192.0/19220.1.192.1 to 220.1.223.254220.1.223.2558,190
16220.1.224.0/19220.1.224.1 to 220.1.255.254220.1.255.2558,190
17220.2.0.0/19220.2.0.1 to 220.2.31.254220.2.31.2558,190
18220.2.32.0/19220.2.32.1 to 220.2.63.254220.2.63.2558,190
19220.2.64.0/19220.2.64.1 to 220.2.95.254220.2.95.2558,190
20220.2.96.0/19220.2.96.1 to 220.2.127.254220.2.127.2558,190
21220.2.128.0/19220.2.128.1 to 220.2.159.254220.2.159.2558,190
22220.2.160.0/19220.2.160.1 to 220.2.191.254220.2.191.2558,190
23220.2.192.0/19220.2.192.1 to 220.2.223.254220.2.223.2558,190
24220.2.224.0/19220.2.224.1 to 220.2.255.254220.2.255.2558,190
25220.3.0.0/19220.3.0.1 to 220.3.31.254220.3.31.2558,190
26220.3.32.0/19220.3.32.1 to 220.3.63.254220.3.63.2558,190
27220.3.64.0/19220.3.64.1 to 220.3.95.254220.3.95.2558,190
28220.3.96.0/19220.3.96.1 to 220.3.127.254220.3.127.2558,190
29220.3.128.0/19220.3.128.1 to 220.3.159.254220.3.159.2558,190
30220.3.160.0/19220.3.160.1 to 220.3.191.254220.3.191.2558,190
31220.3.192.0/19220.3.192.1 to 220.3.223.254220.3.223.2558,190
32220.3.224.0/19220.3.224.1 to 220.3.255.254220.3.255.2558,190
33220.4.0.0/19220.4.0.1 to 220.4.31.254220.4.31.2558,190
34220.4.32.0/19220.4.32.1 to 220.4.63.254220.4.63.2558,190
35220.4.64.0/19220.4.64.1 to 220.4.95.254220.4.95.2558,190
36220.4.96.0/19220.4.96.1 to 220.4.127.254220.4.127.2558,190
37220.4.128.0/19220.4.128.1 to 220.4.159.254220.4.159.2558,190
38220.4.160.0/19220.4.160.1 to 220.4.191.254220.4.191.2558,190
39220.4.192.0/19220.4.192.1 to 220.4.223.254220.4.223.2558,190
40220.4.224.0/19220.4.224.1 to 220.4.255.254220.4.255.2558,190
41220.5.0.0/19220.5.0.1 to 220.5.31.254220.5.31.2558,190
42220.5.32.0/19220.5.32.1 to 220.5.63.254220.5.63.2558,190
43220.5.64.0/19220.5.64.1 to 220.5.95.254220.5.95.2558,190
44220.5.96.0/19220.5.96.1 to 220.5.127.254220.5.127.2558,190
45220.5.128.0/19220.5.128.1 to 220.5.159.254220.5.159.2558,190
46220.5.160.0/19220.5.160.1 to 220.5.191.254220.5.191.2558,190
47220.5.192.0/19220.5.192.1 to 220.5.223.254220.5.223.2558,190
48220.5.224.0/19220.5.224.1 to 220.5.255.254220.5.255.2558,190
49220.6.0.0/19220.6.0.1 to 220.6.31.254220.6.31.2558,190
50220.6.32.0/19220.6.32.1 to 220.6.63.254220.6.63.2558,190
51220.6.64.0/19220.6.64.1 to 220.6.95.254220.6.95.2558,190
52220.6.96.0/19220.6.96.1 to 220.6.127.254220.6.127.2558,190
53220.6.128.0/19220.6.128.1 to 220.6.159.254220.6.159.2558,190
54220.6.160.0/19220.6.160.1 to 220.6.191.254220.6.191.2558,190
55220.6.192.0/19220.6.192.1 to 220.6.223.254220.6.223.2558,190
56220.6.224.0/19220.6.224.1 to 220.6.255.254220.6.255.2558,190
57220.7.0.0/19220.7.0.1 to 220.7.31.254220.7.31.2558,190
58220.7.32.0/19220.7.32.1 to 220.7.63.254220.7.63.2558,190
59220.7.64.0/19220.7.64.1 to 220.7.95.254220.7.95.2558,190
60220.7.96.0/19220.7.96.1 to 220.7.127.254220.7.127.2558,190
61220.7.128.0/19220.7.128.1 to 220.7.159.254220.7.159.2558,190
62220.7.160.0/19220.7.160.1 to 220.7.191.254220.7.191.2558,190
63220.7.192.0/19220.7.192.1 to 220.7.223.254220.7.223.2558,190
64220.7.224.0/19220.7.224.1 to 220.7.255.254220.7.255.2558,190
65220.8.0.0/19220.8.0.1 to 220.8.31.254220.8.31.2558,190
66220.8.32.0/19220.8.32.1 to 220.8.63.254220.8.63.2558,190
67220.8.64.0/19220.8.64.1 to 220.8.95.254220.8.95.2558,190
68220.8.96.0/19220.8.96.1 to 220.8.127.254220.8.127.2558,190
69220.8.128.0/19220.8.128.1 to 220.8.159.254220.8.159.2558,190
70220.8.160.0/19220.8.160.1 to 220.8.191.254220.8.191.2558,190
71220.8.192.0/19220.8.192.1 to 220.8.223.254220.8.223.2558,190
72220.8.224.0/19220.8.224.1 to 220.8.255.254220.8.255.2558,190
73220.9.0.0/19220.9.0.1 to 220.9.31.254220.9.31.2558,190
74220.9.32.0/19220.9.32.1 to 220.9.63.254220.9.63.2558,190
75220.9.64.0/19220.9.64.1 to 220.9.95.254220.9.95.2558,190
76220.9.96.0/19220.9.96.1 to 220.9.127.254220.9.127.2558,190
77220.9.128.0/19220.9.128.1 to 220.9.159.254220.9.159.2558,190
78220.9.160.0/19220.9.160.1 to 220.9.191.254220.9.191.2558,190
79220.9.192.0/19220.9.192.1 to 220.9.223.254220.9.223.2558,190
80220.9.224.0/19220.9.224.1 to 220.9.255.254220.9.255.2558,190
81220.10.0.0/19220.10.0.1 to 220.10.31.254220.10.31.2558,190
82220.10.32.0/19220.10.32.1 to 220.10.63.254220.10.63.2558,190
83220.10.64.0/19220.10.64.1 to 220.10.95.254220.10.95.2558,190
84220.10.96.0/19220.10.96.1 to 220.10.127.254220.10.127.2558,190
85220.10.128.0/19220.10.128.1 to 220.10.159.254220.10.159.2558,190
86220.10.160.0/19220.10.160.1 to 220.10.191.254220.10.191.2558,190
87220.10.192.0/19220.10.192.1 to 220.10.223.254220.10.223.2558,190
88220.10.224.0/19220.10.224.1 to 220.10.255.254220.10.255.2558,190
89220.11.0.0/19220.11.0.1 to 220.11.31.254220.11.31.2558,190
90220.11.32.0/19220.11.32.1 to 220.11.63.254220.11.63.2558,190
91220.11.64.0/19220.11.64.1 to 220.11.95.254220.11.95.2558,190
92220.11.96.0/19220.11.96.1 to 220.11.127.254220.11.127.2558,190
93220.11.128.0/19220.11.128.1 to 220.11.159.254220.11.159.2558,190
94220.11.160.0/19220.11.160.1 to 220.11.191.254220.11.191.2558,190
95220.11.192.0/19220.11.192.1 to 220.11.223.254220.11.223.2558,190
96220.11.224.0/19220.11.224.1 to 220.11.255.254220.11.255.2558,190
97220.12.0.0/19220.12.0.1 to 220.12.31.254220.12.31.2558,190
98220.12.32.0/19220.12.32.1 to 220.12.63.254220.12.63.2558,190
99220.12.64.0/19220.12.64.1 to 220.12.95.254220.12.95.2558,190
100220.12.96.0/19220.12.96.1 to 220.12.127.254220.12.127.2558,190
101220.12.128.0/19220.12.128.1 to 220.12.159.254220.12.159.2558,190
102220.12.160.0/19220.12.160.1 to 220.12.191.254220.12.191.2558,190
103220.12.192.0/19220.12.192.1 to 220.12.223.254220.12.223.2558,190
104220.12.224.0/19220.12.224.1 to 220.12.255.254220.12.255.2558,190
105220.13.0.0/19220.13.0.1 to 220.13.31.254220.13.31.2558,190
106220.13.32.0/19220.13.32.1 to 220.13.63.254220.13.63.2558,190
107220.13.64.0/19220.13.64.1 to 220.13.95.254220.13.95.2558,190
108220.13.96.0/19220.13.96.1 to 220.13.127.254220.13.127.2558,190
109220.13.128.0/19220.13.128.1 to 220.13.159.254220.13.159.2558,190
110220.13.160.0/19220.13.160.1 to 220.13.191.254220.13.191.2558,190
111220.13.192.0/19220.13.192.1 to 220.13.223.254220.13.223.2558,190
112220.13.224.0/19220.13.224.1 to 220.13.255.254220.13.255.2558,190
113220.14.0.0/19220.14.0.1 to 220.14.31.254220.14.31.2558,190
114220.14.32.0/19220.14.32.1 to 220.14.63.254220.14.63.2558,190
115220.14.64.0/19220.14.64.1 to 220.14.95.254220.14.95.2558,190
116220.14.96.0/19220.14.96.1 to 220.14.127.254220.14.127.2558,190
117220.14.128.0/19220.14.128.1 to 220.14.159.254220.14.159.2558,190
118220.14.160.0/19220.14.160.1 to 220.14.191.254220.14.191.2558,190
119220.14.192.0/19220.14.192.1 to 220.14.223.254220.14.223.2558,190
120220.14.224.0/19220.14.224.1 to 220.14.255.254220.14.255.2558,190
121220.15.0.0/19220.15.0.1 to 220.15.31.254220.15.31.2558,190
122220.15.32.0/19220.15.32.1 to 220.15.63.254220.15.63.2558,190
123220.15.64.0/19220.15.64.1 to 220.15.95.254220.15.95.2558,190
124220.15.96.0/19220.15.96.1 to 220.15.127.254220.15.127.2558,190
125220.15.128.0/19220.15.128.1 to 220.15.159.254220.15.159.2558,190
126220.15.160.0/19220.15.160.1 to 220.15.191.254220.15.191.2558,190
127220.15.192.0/19220.15.192.1 to 220.15.223.254220.15.223.2558,190
128220.15.224.0/19220.15.224.1 to 220.15.255.254220.15.255.2558,190
129220.16.0.0/19220.16.0.1 to 220.16.31.254220.16.31.2558,190
130220.16.32.0/19220.16.32.1 to 220.16.63.254220.16.63.2558,190
131220.16.64.0/19220.16.64.1 to 220.16.95.254220.16.95.2558,190
132220.16.96.0/19220.16.96.1 to 220.16.127.254220.16.127.2558,190
133220.16.128.0/19220.16.128.1 to 220.16.159.254220.16.159.2558,190
134220.16.160.0/19220.16.160.1 to 220.16.191.254220.16.191.2558,190
135220.16.192.0/19220.16.192.1 to 220.16.223.254220.16.223.2558,190
136220.16.224.0/19220.16.224.1 to 220.16.255.254220.16.255.2558,190
137220.17.0.0/19220.17.0.1 to 220.17.31.254220.17.31.2558,190
138220.17.32.0/19220.17.32.1 to 220.17.63.254220.17.63.2558,190
139220.17.64.0/19220.17.64.1 to 220.17.95.254220.17.95.2558,190
140220.17.96.0/19220.17.96.1 to 220.17.127.254220.17.127.2558,190
141220.17.128.0/19220.17.128.1 to 220.17.159.254220.17.159.2558,190
142220.17.160.0/19220.17.160.1 to 220.17.191.254220.17.191.2558,190
143220.17.192.0/19220.17.192.1 to 220.17.223.254220.17.223.2558,190
144220.17.224.0/19220.17.224.1 to 220.17.255.254220.17.255.2558,190
145220.18.0.0/19220.18.0.1 to 220.18.31.254220.18.31.2558,190
146220.18.32.0/19220.18.32.1 to 220.18.63.254220.18.63.2558,190
147220.18.64.0/19220.18.64.1 to 220.18.95.254220.18.95.2558,190
148220.18.96.0/19220.18.96.1 to 220.18.127.254220.18.127.2558,190
149220.18.128.0/19220.18.128.1 to 220.18.159.254220.18.159.2558,190
150220.18.160.0/19220.18.160.1 to 220.18.191.254220.18.191.2558,190
151220.18.192.0/19220.18.192.1 to 220.18.223.254220.18.223.2558,190
152220.18.224.0/19220.18.224.1 to 220.18.255.254220.18.255.2558,190
153220.19.0.0/19220.19.0.1 to 220.19.31.254220.19.31.2558,190
154220.19.32.0/19220.19.32.1 to 220.19.63.254220.19.63.2558,190
155220.19.64.0/19220.19.64.1 to 220.19.95.254220.19.95.2558,190
156220.19.96.0/19220.19.96.1 to 220.19.127.254220.19.127.2558,190
157220.19.128.0/19220.19.128.1 to 220.19.159.254220.19.159.2558,190
158220.19.160.0/19220.19.160.1 to 220.19.191.254220.19.191.2558,190
159220.19.192.0/19220.19.192.1 to 220.19.223.254220.19.223.2558,190
160220.19.224.0/19220.19.224.1 to 220.19.255.254220.19.255.2558,190
161220.20.0.0/19220.20.0.1 to 220.20.31.254220.20.31.2558,190
162220.20.32.0/19220.20.32.1 to 220.20.63.254220.20.63.2558,190
163220.20.64.0/19220.20.64.1 to 220.20.95.254220.20.95.2558,190
164220.20.96.0/19220.20.96.1 to 220.20.127.254220.20.127.2558,190
165220.20.128.0/19220.20.128.1 to 220.20.159.254220.20.159.2558,190
166220.20.160.0/19220.20.160.1 to 220.20.191.254220.20.191.2558,190
167220.20.192.0/19220.20.192.1 to 220.20.223.254220.20.223.2558,190
168220.20.224.0/19220.20.224.1 to 220.20.255.254220.20.255.2558,190
169220.21.0.0/19220.21.0.1 to 220.21.31.254220.21.31.2558,190
170220.21.32.0/19220.21.32.1 to 220.21.63.254220.21.63.2558,190
171220.21.64.0/19220.21.64.1 to 220.21.95.254220.21.95.2558,190
172220.21.96.0/19220.21.96.1 to 220.21.127.254220.21.127.2558,190
173220.21.128.0/19220.21.128.1 to 220.21.159.254220.21.159.2558,190
174220.21.160.0/19220.21.160.1 to 220.21.191.254220.21.191.2558,190
175220.21.192.0/19220.21.192.1 to 220.21.223.254220.21.223.2558,190
176220.21.224.0/19220.21.224.1 to 220.21.255.254220.21.255.2558,190
177220.22.0.0/19220.22.0.1 to 220.22.31.254220.22.31.2558,190
178220.22.32.0/19220.22.32.1 to 220.22.63.254220.22.63.2558,190
179220.22.64.0/19220.22.64.1 to 220.22.95.254220.22.95.2558,190
180220.22.96.0/19220.22.96.1 to 220.22.127.254220.22.127.2558,190
181220.22.128.0/19220.22.128.1 to 220.22.159.254220.22.159.2558,190
182220.22.160.0/19220.22.160.1 to 220.22.191.254220.22.191.2558,190
183220.22.192.0/19220.22.192.1 to 220.22.223.254220.22.223.2558,190
184220.22.224.0/19220.22.224.1 to 220.22.255.254220.22.255.2558,190
185220.23.0.0/19220.23.0.1 to 220.23.31.254220.23.31.2558,190
186220.23.32.0/19220.23.32.1 to 220.23.63.254220.23.63.2558,190
187220.23.64.0/19220.23.64.1 to 220.23.95.254220.23.95.2558,190
188220.23.96.0/19220.23.96.1 to 220.23.127.254220.23.127.2558,190
189220.23.128.0/19220.23.128.1 to 220.23.159.254220.23.159.2558,190
190220.23.160.0/19220.23.160.1 to 220.23.191.254220.23.191.2558,190
191220.23.192.0/19220.23.192.1 to 220.23.223.254220.23.223.2558,190
192220.23.224.0/19220.23.224.1 to 220.23.255.254220.23.255.2558,190
193220.24.0.0/19220.24.0.1 to 220.24.31.254220.24.31.2558,190
194220.24.32.0/19220.24.32.1 to 220.24.63.254220.24.63.2558,190
195220.24.64.0/19220.24.64.1 to 220.24.95.254220.24.95.2558,190
196220.24.96.0/19220.24.96.1 to 220.24.127.254220.24.127.2558,190
197220.24.128.0/19220.24.128.1 to 220.24.159.254220.24.159.2558,190
198220.24.160.0/19220.24.160.1 to 220.24.191.254220.24.191.2558,190
199220.24.192.0/19220.24.192.1 to 220.24.223.254220.24.223.2558,190
200220.24.224.0/19220.24.224.1 to 220.24.255.254220.24.255.2558,190
201220.25.0.0/19220.25.0.1 to 220.25.31.254220.25.31.2558,190
202220.25.32.0/19220.25.32.1 to 220.25.63.254220.25.63.2558,190
203220.25.64.0/19220.25.64.1 to 220.25.95.254220.25.95.2558,190
204220.25.96.0/19220.25.96.1 to 220.25.127.254220.25.127.2558,190
205220.25.128.0/19220.25.128.1 to 220.25.159.254220.25.159.2558,190
206220.25.160.0/19220.25.160.1 to 220.25.191.254220.25.191.2558,190
207220.25.192.0/19220.25.192.1 to 220.25.223.254220.25.223.2558,190
208220.25.224.0/19220.25.224.1 to 220.25.255.254220.25.255.2558,190
209220.26.0.0/19220.26.0.1 to 220.26.31.254220.26.31.2558,190
210220.26.32.0/19220.26.32.1 to 220.26.63.254220.26.63.2558,190
211220.26.64.0/19220.26.64.1 to 220.26.95.254220.26.95.2558,190
212220.26.96.0/19220.26.96.1 to 220.26.127.254220.26.127.2558,190
213220.26.128.0/19220.26.128.1 to 220.26.159.254220.26.159.2558,190
214220.26.160.0/19220.26.160.1 to 220.26.191.254220.26.191.2558,190
215220.26.192.0/19220.26.192.1 to 220.26.223.254220.26.223.2558,190
216220.26.224.0/19220.26.224.1 to 220.26.255.254220.26.255.2558,190
217220.27.0.0/19220.27.0.1 to 220.27.31.254220.27.31.2558,190
218220.27.32.0/19220.27.32.1 to 220.27.63.254220.27.63.2558,190
219220.27.64.0/19220.27.64.1 to 220.27.95.254220.27.95.2558,190
220220.27.96.0/19220.27.96.1 to 220.27.127.254220.27.127.2558,190
221220.27.128.0/19220.27.128.1 to 220.27.159.254220.27.159.2558,190
222220.27.160.0/19220.27.160.1 to 220.27.191.254220.27.191.2558,190
223220.27.192.0/19220.27.192.1 to 220.27.223.254220.27.223.2558,190
224220.27.224.0/19220.27.224.1 to 220.27.255.254220.27.255.2558,190
225220.28.0.0/19220.28.0.1 to 220.28.31.254220.28.31.2558,190
226220.28.32.0/19220.28.32.1 to 220.28.63.254220.28.63.2558,190
227220.28.64.0/19220.28.64.1 to 220.28.95.254220.28.95.2558,190
228220.28.96.0/19220.28.96.1 to 220.28.127.254220.28.127.2558,190
229220.28.128.0/19220.28.128.1 to 220.28.159.254220.28.159.2558,190
230220.28.160.0/19220.28.160.1 to 220.28.191.254220.28.191.2558,190
231220.28.192.0/19220.28.192.1 to 220.28.223.254220.28.223.2558,190
232220.28.224.0/19220.28.224.1 to 220.28.255.254220.28.255.2558,190
233220.29.0.0/19220.29.0.1 to 220.29.31.254220.29.31.2558,190
234220.29.32.0/19220.29.32.1 to 220.29.63.254220.29.63.2558,190
235220.29.64.0/19220.29.64.1 to 220.29.95.254220.29.95.2558,190
236220.29.96.0/19220.29.96.1 to 220.29.127.254220.29.127.2558,190
237220.29.128.0/19220.29.128.1 to 220.29.159.254220.29.159.2558,190
238220.29.160.0/19220.29.160.1 to 220.29.191.254220.29.191.2558,190
239220.29.192.0/19220.29.192.1 to 220.29.223.254220.29.223.2558,190
240220.29.224.0/19220.29.224.1 to 220.29.255.254220.29.255.2558,190
241220.30.0.0/19220.30.0.1 to 220.30.31.254220.30.31.2558,190
242220.30.32.0/19220.30.32.1 to 220.30.63.254220.30.63.2558,190
243220.30.64.0/19220.30.64.1 to 220.30.95.254220.30.95.2558,190
244220.30.96.0/19220.30.96.1 to 220.30.127.254220.30.127.2558,190
245220.30.128.0/19220.30.128.1 to 220.30.159.254220.30.159.2558,190
246220.30.160.0/19220.30.160.1 to 220.30.191.254220.30.191.2558,190
247220.30.192.0/19220.30.192.1 to 220.30.223.254220.30.223.2558,190
248220.30.224.0/19220.30.224.1 to 220.30.255.254220.30.255.2558,190
249220.31.0.0/19220.31.0.1 to 220.31.31.254220.31.31.2558,190
250220.31.32.0/19220.31.32.1 to 220.31.63.254220.31.63.2558,190
251220.31.64.0/19220.31.64.1 to 220.31.95.254220.31.95.2558,190
252220.31.96.0/19220.31.96.1 to 220.31.127.254220.31.127.2558,190
253220.31.128.0/19220.31.128.1 to 220.31.159.254220.31.159.2558,190
254220.31.160.0/19220.31.160.1 to 220.31.191.254220.31.191.2558,190
255220.31.192.0/19220.31.192.1 to 220.31.223.254220.31.223.2558,190
256220.31.224.0/19220.31.224.1 to 220.31.255.254220.31.255.2558,190

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.