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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.

Network220.89.0.0/17
Usable hosts32,766
Subnet mask255.255.128.0
Addresses32,768
Network address
220.89.0.0
Broadcast address
220.89.127.255
First usable
220.89.0.1
Last usable
220.89.127.254
Usable hosts
32,766 (32,768 less the network and broadcast addresses)
Subnet mask
255.255.128.0
Wildcard mask
0.0.127.255 (Cisco ACLs, OSPF)
Prefix length
/17
Type
Public public
Old class
C (default /24)
As numbers
Hex DC590000 · Integer 3696820224 to 3696852991
Reverse DNS zones
0.89.220.in-addr.arpa
1.89.220.in-addr.arpa
2.89.220.in-addr.arpa
3.89.220.in-addr.arpa
4.89.220.in-addr.arpa
5.89.220.in-addr.arpa
6.89.220.in-addr.arpa
7.89.220.in-addr.arpa
8.89.220.in-addr.arpa
9.89.220.in-addr.arpa
10.89.220.in-addr.arpa
11.89.220.in-addr.arpa
12.89.220.in-addr.arpa
13.89.220.in-addr.arpa
14.89.220.in-addr.arpa
15.89.220.in-addr.arpa
and 112 more
/17 is not on a 8-bit boundary, so it takes 128 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11011100.01011001.00000000.00000000220.89.0.0
Subnet mask11111111.11111111.10000000.00000000255.255.128.0
Network11011100.01011001.00000000.00000000220.89.0.0
Broadcast11011100.01011001.01111111.11111111220.89.127.255
Split into smaller subnets/27
/18 (2)/19 (4)/20 (8)/21 (16)/22 (32)/23 (64)/24 (128)/25 (256)/26 (512)/27 (1,024)/28 (2,048)/29 (4,096)

220.89.0.0/17 makes 1,024 subnets of /27; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1220.89.0.0/27220.89.0.1 to 220.89.0.30220.89.0.3130
2220.89.0.32/27220.89.0.33 to 220.89.0.62220.89.0.6330
3220.89.0.64/27220.89.0.65 to 220.89.0.94220.89.0.9530
4220.89.0.96/27220.89.0.97 to 220.89.0.126220.89.0.12730
5220.89.0.128/27220.89.0.129 to 220.89.0.158220.89.0.15930
6220.89.0.160/27220.89.0.161 to 220.89.0.190220.89.0.19130
7220.89.0.192/27220.89.0.193 to 220.89.0.222220.89.0.22330
8220.89.0.224/27220.89.0.225 to 220.89.0.254220.89.0.25530
9220.89.1.0/27220.89.1.1 to 220.89.1.30220.89.1.3130
10220.89.1.32/27220.89.1.33 to 220.89.1.62220.89.1.6330
11220.89.1.64/27220.89.1.65 to 220.89.1.94220.89.1.9530
12220.89.1.96/27220.89.1.97 to 220.89.1.126220.89.1.12730
13220.89.1.128/27220.89.1.129 to 220.89.1.158220.89.1.15930
14220.89.1.160/27220.89.1.161 to 220.89.1.190220.89.1.19130
15220.89.1.192/27220.89.1.193 to 220.89.1.222220.89.1.22330
16220.89.1.224/27220.89.1.225 to 220.89.1.254220.89.1.25530
17220.89.2.0/27220.89.2.1 to 220.89.2.30220.89.2.3130
18220.89.2.32/27220.89.2.33 to 220.89.2.62220.89.2.6330
19220.89.2.64/27220.89.2.65 to 220.89.2.94220.89.2.9530
20220.89.2.96/27220.89.2.97 to 220.89.2.126220.89.2.12730
21220.89.2.128/27220.89.2.129 to 220.89.2.158220.89.2.15930
22220.89.2.160/27220.89.2.161 to 220.89.2.190220.89.2.19130
23220.89.2.192/27220.89.2.193 to 220.89.2.222220.89.2.22330
24220.89.2.224/27220.89.2.225 to 220.89.2.254220.89.2.25530
25220.89.3.0/27220.89.3.1 to 220.89.3.30220.89.3.3130
26220.89.3.32/27220.89.3.33 to 220.89.3.62220.89.3.6330
27220.89.3.64/27220.89.3.65 to 220.89.3.94220.89.3.9530
28220.89.3.96/27220.89.3.97 to 220.89.3.126220.89.3.12730
29220.89.3.128/27220.89.3.129 to 220.89.3.158220.89.3.15930
30220.89.3.160/27220.89.3.161 to 220.89.3.190220.89.3.19130
31220.89.3.192/27220.89.3.193 to 220.89.3.222220.89.3.22330
32220.89.3.224/27220.89.3.225 to 220.89.3.254220.89.3.25530
33220.89.4.0/27220.89.4.1 to 220.89.4.30220.89.4.3130
34220.89.4.32/27220.89.4.33 to 220.89.4.62220.89.4.6330
35220.89.4.64/27220.89.4.65 to 220.89.4.94220.89.4.9530
36220.89.4.96/27220.89.4.97 to 220.89.4.126220.89.4.12730
37220.89.4.128/27220.89.4.129 to 220.89.4.158220.89.4.15930
38220.89.4.160/27220.89.4.161 to 220.89.4.190220.89.4.19130
39220.89.4.192/27220.89.4.193 to 220.89.4.222220.89.4.22330
40220.89.4.224/27220.89.4.225 to 220.89.4.254220.89.4.25530
41220.89.5.0/27220.89.5.1 to 220.89.5.30220.89.5.3130
42220.89.5.32/27220.89.5.33 to 220.89.5.62220.89.5.6330
43220.89.5.64/27220.89.5.65 to 220.89.5.94220.89.5.9530
44220.89.5.96/27220.89.5.97 to 220.89.5.126220.89.5.12730
45220.89.5.128/27220.89.5.129 to 220.89.5.158220.89.5.15930
46220.89.5.160/27220.89.5.161 to 220.89.5.190220.89.5.19130
47220.89.5.192/27220.89.5.193 to 220.89.5.222220.89.5.22330
48220.89.5.224/27220.89.5.225 to 220.89.5.254220.89.5.25530
49220.89.6.0/27220.89.6.1 to 220.89.6.30220.89.6.3130
50220.89.6.32/27220.89.6.33 to 220.89.6.62220.89.6.6330
51220.89.6.64/27220.89.6.65 to 220.89.6.94220.89.6.9530
52220.89.6.96/27220.89.6.97 to 220.89.6.126220.89.6.12730
53220.89.6.128/27220.89.6.129 to 220.89.6.158220.89.6.15930
54220.89.6.160/27220.89.6.161 to 220.89.6.190220.89.6.19130
55220.89.6.192/27220.89.6.193 to 220.89.6.222220.89.6.22330
56220.89.6.224/27220.89.6.225 to 220.89.6.254220.89.6.25530
57220.89.7.0/27220.89.7.1 to 220.89.7.30220.89.7.3130
58220.89.7.32/27220.89.7.33 to 220.89.7.62220.89.7.6330
59220.89.7.64/27220.89.7.65 to 220.89.7.94220.89.7.9530
60220.89.7.96/27220.89.7.97 to 220.89.7.126220.89.7.12730
61220.89.7.128/27220.89.7.129 to 220.89.7.158220.89.7.15930
62220.89.7.160/27220.89.7.161 to 220.89.7.190220.89.7.19130
63220.89.7.192/27220.89.7.193 to 220.89.7.222220.89.7.22330
64220.89.7.224/27220.89.7.225 to 220.89.7.254220.89.7.25530
65220.89.8.0/27220.89.8.1 to 220.89.8.30220.89.8.3130
66220.89.8.32/27220.89.8.33 to 220.89.8.62220.89.8.6330
67220.89.8.64/27220.89.8.65 to 220.89.8.94220.89.8.9530
68220.89.8.96/27220.89.8.97 to 220.89.8.126220.89.8.12730
69220.89.8.128/27220.89.8.129 to 220.89.8.158220.89.8.15930
70220.89.8.160/27220.89.8.161 to 220.89.8.190220.89.8.19130
71220.89.8.192/27220.89.8.193 to 220.89.8.222220.89.8.22330
72220.89.8.224/27220.89.8.225 to 220.89.8.254220.89.8.25530
73220.89.9.0/27220.89.9.1 to 220.89.9.30220.89.9.3130
74220.89.9.32/27220.89.9.33 to 220.89.9.62220.89.9.6330
75220.89.9.64/27220.89.9.65 to 220.89.9.94220.89.9.9530
76220.89.9.96/27220.89.9.97 to 220.89.9.126220.89.9.12730
77220.89.9.128/27220.89.9.129 to 220.89.9.158220.89.9.15930
78220.89.9.160/27220.89.9.161 to 220.89.9.190220.89.9.19130
79220.89.9.192/27220.89.9.193 to 220.89.9.222220.89.9.22330
80220.89.9.224/27220.89.9.225 to 220.89.9.254220.89.9.25530
81220.89.10.0/27220.89.10.1 to 220.89.10.30220.89.10.3130
82220.89.10.32/27220.89.10.33 to 220.89.10.62220.89.10.6330
83220.89.10.64/27220.89.10.65 to 220.89.10.94220.89.10.9530
84220.89.10.96/27220.89.10.97 to 220.89.10.126220.89.10.12730
85220.89.10.128/27220.89.10.129 to 220.89.10.158220.89.10.15930
86220.89.10.160/27220.89.10.161 to 220.89.10.190220.89.10.19130
87220.89.10.192/27220.89.10.193 to 220.89.10.222220.89.10.22330
88220.89.10.224/27220.89.10.225 to 220.89.10.254220.89.10.25530
89220.89.11.0/27220.89.11.1 to 220.89.11.30220.89.11.3130
90220.89.11.32/27220.89.11.33 to 220.89.11.62220.89.11.6330
91220.89.11.64/27220.89.11.65 to 220.89.11.94220.89.11.9530
92220.89.11.96/27220.89.11.97 to 220.89.11.126220.89.11.12730
93220.89.11.128/27220.89.11.129 to 220.89.11.158220.89.11.15930
94220.89.11.160/27220.89.11.161 to 220.89.11.190220.89.11.19130
95220.89.11.192/27220.89.11.193 to 220.89.11.222220.89.11.22330
96220.89.11.224/27220.89.11.225 to 220.89.11.254220.89.11.25530
97220.89.12.0/27220.89.12.1 to 220.89.12.30220.89.12.3130
98220.89.12.32/27220.89.12.33 to 220.89.12.62220.89.12.6330
99220.89.12.64/27220.89.12.65 to 220.89.12.94220.89.12.9530
100220.89.12.96/27220.89.12.97 to 220.89.12.126220.89.12.12730
101220.89.12.128/27220.89.12.129 to 220.89.12.158220.89.12.15930
102220.89.12.160/27220.89.12.161 to 220.89.12.190220.89.12.19130
103220.89.12.192/27220.89.12.193 to 220.89.12.222220.89.12.22330
104220.89.12.224/27220.89.12.225 to 220.89.12.254220.89.12.25530
105220.89.13.0/27220.89.13.1 to 220.89.13.30220.89.13.3130
106220.89.13.32/27220.89.13.33 to 220.89.13.62220.89.13.6330
107220.89.13.64/27220.89.13.65 to 220.89.13.94220.89.13.9530
108220.89.13.96/27220.89.13.97 to 220.89.13.126220.89.13.12730
109220.89.13.128/27220.89.13.129 to 220.89.13.158220.89.13.15930
110220.89.13.160/27220.89.13.161 to 220.89.13.190220.89.13.19130
111220.89.13.192/27220.89.13.193 to 220.89.13.222220.89.13.22330
112220.89.13.224/27220.89.13.225 to 220.89.13.254220.89.13.25530
113220.89.14.0/27220.89.14.1 to 220.89.14.30220.89.14.3130
114220.89.14.32/27220.89.14.33 to 220.89.14.62220.89.14.6330
115220.89.14.64/27220.89.14.65 to 220.89.14.94220.89.14.9530
116220.89.14.96/27220.89.14.97 to 220.89.14.126220.89.14.12730
117220.89.14.128/27220.89.14.129 to 220.89.14.158220.89.14.15930
118220.89.14.160/27220.89.14.161 to 220.89.14.190220.89.14.19130
119220.89.14.192/27220.89.14.193 to 220.89.14.222220.89.14.22330
120220.89.14.224/27220.89.14.225 to 220.89.14.254220.89.14.25530
121220.89.15.0/27220.89.15.1 to 220.89.15.30220.89.15.3130
122220.89.15.32/27220.89.15.33 to 220.89.15.62220.89.15.6330
123220.89.15.64/27220.89.15.65 to 220.89.15.94220.89.15.9530
124220.89.15.96/27220.89.15.97 to 220.89.15.126220.89.15.12730
125220.89.15.128/27220.89.15.129 to 220.89.15.158220.89.15.15930
126220.89.15.160/27220.89.15.161 to 220.89.15.190220.89.15.19130
127220.89.15.192/27220.89.15.193 to 220.89.15.222220.89.15.22330
128220.89.15.224/27220.89.15.225 to 220.89.15.254220.89.15.25530
129220.89.16.0/27220.89.16.1 to 220.89.16.30220.89.16.3130
130220.89.16.32/27220.89.16.33 to 220.89.16.62220.89.16.6330
131220.89.16.64/27220.89.16.65 to 220.89.16.94220.89.16.9530
132220.89.16.96/27220.89.16.97 to 220.89.16.126220.89.16.12730
133220.89.16.128/27220.89.16.129 to 220.89.16.158220.89.16.15930
134220.89.16.160/27220.89.16.161 to 220.89.16.190220.89.16.19130
135220.89.16.192/27220.89.16.193 to 220.89.16.222220.89.16.22330
136220.89.16.224/27220.89.16.225 to 220.89.16.254220.89.16.25530
137220.89.17.0/27220.89.17.1 to 220.89.17.30220.89.17.3130
138220.89.17.32/27220.89.17.33 to 220.89.17.62220.89.17.6330
139220.89.17.64/27220.89.17.65 to 220.89.17.94220.89.17.9530
140220.89.17.96/27220.89.17.97 to 220.89.17.126220.89.17.12730
141220.89.17.128/27220.89.17.129 to 220.89.17.158220.89.17.15930
142220.89.17.160/27220.89.17.161 to 220.89.17.190220.89.17.19130
143220.89.17.192/27220.89.17.193 to 220.89.17.222220.89.17.22330
144220.89.17.224/27220.89.17.225 to 220.89.17.254220.89.17.25530
145220.89.18.0/27220.89.18.1 to 220.89.18.30220.89.18.3130
146220.89.18.32/27220.89.18.33 to 220.89.18.62220.89.18.6330
147220.89.18.64/27220.89.18.65 to 220.89.18.94220.89.18.9530
148220.89.18.96/27220.89.18.97 to 220.89.18.126220.89.18.12730
149220.89.18.128/27220.89.18.129 to 220.89.18.158220.89.18.15930
150220.89.18.160/27220.89.18.161 to 220.89.18.190220.89.18.19130
151220.89.18.192/27220.89.18.193 to 220.89.18.222220.89.18.22330
152220.89.18.224/27220.89.18.225 to 220.89.18.254220.89.18.25530
153220.89.19.0/27220.89.19.1 to 220.89.19.30220.89.19.3130
154220.89.19.32/27220.89.19.33 to 220.89.19.62220.89.19.6330
155220.89.19.64/27220.89.19.65 to 220.89.19.94220.89.19.9530
156220.89.19.96/27220.89.19.97 to 220.89.19.126220.89.19.12730
157220.89.19.128/27220.89.19.129 to 220.89.19.158220.89.19.15930
158220.89.19.160/27220.89.19.161 to 220.89.19.190220.89.19.19130
159220.89.19.192/27220.89.19.193 to 220.89.19.222220.89.19.22330
160220.89.19.224/27220.89.19.225 to 220.89.19.254220.89.19.25530
161220.89.20.0/27220.89.20.1 to 220.89.20.30220.89.20.3130
162220.89.20.32/27220.89.20.33 to 220.89.20.62220.89.20.6330
163220.89.20.64/27220.89.20.65 to 220.89.20.94220.89.20.9530
164220.89.20.96/27220.89.20.97 to 220.89.20.126220.89.20.12730
165220.89.20.128/27220.89.20.129 to 220.89.20.158220.89.20.15930
166220.89.20.160/27220.89.20.161 to 220.89.20.190220.89.20.19130
167220.89.20.192/27220.89.20.193 to 220.89.20.222220.89.20.22330
168220.89.20.224/27220.89.20.225 to 220.89.20.254220.89.20.25530
169220.89.21.0/27220.89.21.1 to 220.89.21.30220.89.21.3130
170220.89.21.32/27220.89.21.33 to 220.89.21.62220.89.21.6330
171220.89.21.64/27220.89.21.65 to 220.89.21.94220.89.21.9530
172220.89.21.96/27220.89.21.97 to 220.89.21.126220.89.21.12730
173220.89.21.128/27220.89.21.129 to 220.89.21.158220.89.21.15930
174220.89.21.160/27220.89.21.161 to 220.89.21.190220.89.21.19130
175220.89.21.192/27220.89.21.193 to 220.89.21.222220.89.21.22330
176220.89.21.224/27220.89.21.225 to 220.89.21.254220.89.21.25530
177220.89.22.0/27220.89.22.1 to 220.89.22.30220.89.22.3130
178220.89.22.32/27220.89.22.33 to 220.89.22.62220.89.22.6330
179220.89.22.64/27220.89.22.65 to 220.89.22.94220.89.22.9530
180220.89.22.96/27220.89.22.97 to 220.89.22.126220.89.22.12730
181220.89.22.128/27220.89.22.129 to 220.89.22.158220.89.22.15930
182220.89.22.160/27220.89.22.161 to 220.89.22.190220.89.22.19130
183220.89.22.192/27220.89.22.193 to 220.89.22.222220.89.22.22330
184220.89.22.224/27220.89.22.225 to 220.89.22.254220.89.22.25530
185220.89.23.0/27220.89.23.1 to 220.89.23.30220.89.23.3130
186220.89.23.32/27220.89.23.33 to 220.89.23.62220.89.23.6330
187220.89.23.64/27220.89.23.65 to 220.89.23.94220.89.23.9530
188220.89.23.96/27220.89.23.97 to 220.89.23.126220.89.23.12730
189220.89.23.128/27220.89.23.129 to 220.89.23.158220.89.23.15930
190220.89.23.160/27220.89.23.161 to 220.89.23.190220.89.23.19130
191220.89.23.192/27220.89.23.193 to 220.89.23.222220.89.23.22330
192220.89.23.224/27220.89.23.225 to 220.89.23.254220.89.23.25530
193220.89.24.0/27220.89.24.1 to 220.89.24.30220.89.24.3130
194220.89.24.32/27220.89.24.33 to 220.89.24.62220.89.24.6330
195220.89.24.64/27220.89.24.65 to 220.89.24.94220.89.24.9530
196220.89.24.96/27220.89.24.97 to 220.89.24.126220.89.24.12730
197220.89.24.128/27220.89.24.129 to 220.89.24.158220.89.24.15930
198220.89.24.160/27220.89.24.161 to 220.89.24.190220.89.24.19130
199220.89.24.192/27220.89.24.193 to 220.89.24.222220.89.24.22330
200220.89.24.224/27220.89.24.225 to 220.89.24.254220.89.24.25530
201220.89.25.0/27220.89.25.1 to 220.89.25.30220.89.25.3130
202220.89.25.32/27220.89.25.33 to 220.89.25.62220.89.25.6330
203220.89.25.64/27220.89.25.65 to 220.89.25.94220.89.25.9530
204220.89.25.96/27220.89.25.97 to 220.89.25.126220.89.25.12730
205220.89.25.128/27220.89.25.129 to 220.89.25.158220.89.25.15930
206220.89.25.160/27220.89.25.161 to 220.89.25.190220.89.25.19130
207220.89.25.192/27220.89.25.193 to 220.89.25.222220.89.25.22330
208220.89.25.224/27220.89.25.225 to 220.89.25.254220.89.25.25530
209220.89.26.0/27220.89.26.1 to 220.89.26.30220.89.26.3130
210220.89.26.32/27220.89.26.33 to 220.89.26.62220.89.26.6330
211220.89.26.64/27220.89.26.65 to 220.89.26.94220.89.26.9530
212220.89.26.96/27220.89.26.97 to 220.89.26.126220.89.26.12730
213220.89.26.128/27220.89.26.129 to 220.89.26.158220.89.26.15930
214220.89.26.160/27220.89.26.161 to 220.89.26.190220.89.26.19130
215220.89.26.192/27220.89.26.193 to 220.89.26.222220.89.26.22330
216220.89.26.224/27220.89.26.225 to 220.89.26.254220.89.26.25530
217220.89.27.0/27220.89.27.1 to 220.89.27.30220.89.27.3130
218220.89.27.32/27220.89.27.33 to 220.89.27.62220.89.27.6330
219220.89.27.64/27220.89.27.65 to 220.89.27.94220.89.27.9530
220220.89.27.96/27220.89.27.97 to 220.89.27.126220.89.27.12730
221220.89.27.128/27220.89.27.129 to 220.89.27.158220.89.27.15930
222220.89.27.160/27220.89.27.161 to 220.89.27.190220.89.27.19130
223220.89.27.192/27220.89.27.193 to 220.89.27.222220.89.27.22330
224220.89.27.224/27220.89.27.225 to 220.89.27.254220.89.27.25530
225220.89.28.0/27220.89.28.1 to 220.89.28.30220.89.28.3130
226220.89.28.32/27220.89.28.33 to 220.89.28.62220.89.28.6330
227220.89.28.64/27220.89.28.65 to 220.89.28.94220.89.28.9530
228220.89.28.96/27220.89.28.97 to 220.89.28.126220.89.28.12730
229220.89.28.128/27220.89.28.129 to 220.89.28.158220.89.28.15930
230220.89.28.160/27220.89.28.161 to 220.89.28.190220.89.28.19130
231220.89.28.192/27220.89.28.193 to 220.89.28.222220.89.28.22330
232220.89.28.224/27220.89.28.225 to 220.89.28.254220.89.28.25530
233220.89.29.0/27220.89.29.1 to 220.89.29.30220.89.29.3130
234220.89.29.32/27220.89.29.33 to 220.89.29.62220.89.29.6330
235220.89.29.64/27220.89.29.65 to 220.89.29.94220.89.29.9530
236220.89.29.96/27220.89.29.97 to 220.89.29.126220.89.29.12730
237220.89.29.128/27220.89.29.129 to 220.89.29.158220.89.29.15930
238220.89.29.160/27220.89.29.161 to 220.89.29.190220.89.29.19130
239220.89.29.192/27220.89.29.193 to 220.89.29.222220.89.29.22330
240220.89.29.224/27220.89.29.225 to 220.89.29.254220.89.29.25530
241220.89.30.0/27220.89.30.1 to 220.89.30.30220.89.30.3130
242220.89.30.32/27220.89.30.33 to 220.89.30.62220.89.30.6330
243220.89.30.64/27220.89.30.65 to 220.89.30.94220.89.30.9530
244220.89.30.96/27220.89.30.97 to 220.89.30.126220.89.30.12730
245220.89.30.128/27220.89.30.129 to 220.89.30.158220.89.30.15930
246220.89.30.160/27220.89.30.161 to 220.89.30.190220.89.30.19130
247220.89.30.192/27220.89.30.193 to 220.89.30.222220.89.30.22330
248220.89.30.224/27220.89.30.225 to 220.89.30.254220.89.30.25530
249220.89.31.0/27220.89.31.1 to 220.89.31.30220.89.31.3130
250220.89.31.32/27220.89.31.33 to 220.89.31.62220.89.31.6330
251220.89.31.64/27220.89.31.65 to 220.89.31.94220.89.31.9530
252220.89.31.96/27220.89.31.97 to 220.89.31.126220.89.31.12730
253220.89.31.128/27220.89.31.129 to 220.89.31.158220.89.31.15930
254220.89.31.160/27220.89.31.161 to 220.89.31.190220.89.31.19130
255220.89.31.192/27220.89.31.193 to 220.89.31.222220.89.31.22330
256220.89.31.224/27220.89.31.225 to 220.89.31.254220.89.31.25530

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.