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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.

Network210.167.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
210.167.0.0
Broadcast address
210.167.255.255
First usable
210.167.0.1
Last usable
210.167.255.254
Usable hosts
65,534 (65,536 less the network and broadcast addresses)
Subnet mask
255.255.0.0
Wildcard mask
0.0.255.255 (Cisco ACLs, OSPF)
Prefix length
/16
Type
Public public
Old class
C (default /24)
As numbers
Hex D2A70000 · Integer 3534159872 to 3534225407
Reverse DNS zone
167.210.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11010010.10100111..00000000.00000000210.167.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network11010010.10100111..00000000.00000000210.167.0.0
Broadcast11010010.10100111..11111111.11111111210.167.255.255
Split into smaller subnets/27
/17 (2)/18 (4)/19 (8)/20 (16)/21 (32)/22 (64)/23 (128)/24 (256)/25 (512)/26 (1,024)/27 (2,048)/28 (4,096)

210.167.0.0/16 makes 2,048 subnets of /27; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1210.167.0.0/27210.167.0.1 to 210.167.0.30210.167.0.3130
2210.167.0.32/27210.167.0.33 to 210.167.0.62210.167.0.6330
3210.167.0.64/27210.167.0.65 to 210.167.0.94210.167.0.9530
4210.167.0.96/27210.167.0.97 to 210.167.0.126210.167.0.12730
5210.167.0.128/27210.167.0.129 to 210.167.0.158210.167.0.15930
6210.167.0.160/27210.167.0.161 to 210.167.0.190210.167.0.19130
7210.167.0.192/27210.167.0.193 to 210.167.0.222210.167.0.22330
8210.167.0.224/27210.167.0.225 to 210.167.0.254210.167.0.25530
9210.167.1.0/27210.167.1.1 to 210.167.1.30210.167.1.3130
10210.167.1.32/27210.167.1.33 to 210.167.1.62210.167.1.6330
11210.167.1.64/27210.167.1.65 to 210.167.1.94210.167.1.9530
12210.167.1.96/27210.167.1.97 to 210.167.1.126210.167.1.12730
13210.167.1.128/27210.167.1.129 to 210.167.1.158210.167.1.15930
14210.167.1.160/27210.167.1.161 to 210.167.1.190210.167.1.19130
15210.167.1.192/27210.167.1.193 to 210.167.1.222210.167.1.22330
16210.167.1.224/27210.167.1.225 to 210.167.1.254210.167.1.25530
17210.167.2.0/27210.167.2.1 to 210.167.2.30210.167.2.3130
18210.167.2.32/27210.167.2.33 to 210.167.2.62210.167.2.6330
19210.167.2.64/27210.167.2.65 to 210.167.2.94210.167.2.9530
20210.167.2.96/27210.167.2.97 to 210.167.2.126210.167.2.12730
21210.167.2.128/27210.167.2.129 to 210.167.2.158210.167.2.15930
22210.167.2.160/27210.167.2.161 to 210.167.2.190210.167.2.19130
23210.167.2.192/27210.167.2.193 to 210.167.2.222210.167.2.22330
24210.167.2.224/27210.167.2.225 to 210.167.2.254210.167.2.25530
25210.167.3.0/27210.167.3.1 to 210.167.3.30210.167.3.3130
26210.167.3.32/27210.167.3.33 to 210.167.3.62210.167.3.6330
27210.167.3.64/27210.167.3.65 to 210.167.3.94210.167.3.9530
28210.167.3.96/27210.167.3.97 to 210.167.3.126210.167.3.12730
29210.167.3.128/27210.167.3.129 to 210.167.3.158210.167.3.15930
30210.167.3.160/27210.167.3.161 to 210.167.3.190210.167.3.19130
31210.167.3.192/27210.167.3.193 to 210.167.3.222210.167.3.22330
32210.167.3.224/27210.167.3.225 to 210.167.3.254210.167.3.25530
33210.167.4.0/27210.167.4.1 to 210.167.4.30210.167.4.3130
34210.167.4.32/27210.167.4.33 to 210.167.4.62210.167.4.6330
35210.167.4.64/27210.167.4.65 to 210.167.4.94210.167.4.9530
36210.167.4.96/27210.167.4.97 to 210.167.4.126210.167.4.12730
37210.167.4.128/27210.167.4.129 to 210.167.4.158210.167.4.15930
38210.167.4.160/27210.167.4.161 to 210.167.4.190210.167.4.19130
39210.167.4.192/27210.167.4.193 to 210.167.4.222210.167.4.22330
40210.167.4.224/27210.167.4.225 to 210.167.4.254210.167.4.25530
41210.167.5.0/27210.167.5.1 to 210.167.5.30210.167.5.3130
42210.167.5.32/27210.167.5.33 to 210.167.5.62210.167.5.6330
43210.167.5.64/27210.167.5.65 to 210.167.5.94210.167.5.9530
44210.167.5.96/27210.167.5.97 to 210.167.5.126210.167.5.12730
45210.167.5.128/27210.167.5.129 to 210.167.5.158210.167.5.15930
46210.167.5.160/27210.167.5.161 to 210.167.5.190210.167.5.19130
47210.167.5.192/27210.167.5.193 to 210.167.5.222210.167.5.22330
48210.167.5.224/27210.167.5.225 to 210.167.5.254210.167.5.25530
49210.167.6.0/27210.167.6.1 to 210.167.6.30210.167.6.3130
50210.167.6.32/27210.167.6.33 to 210.167.6.62210.167.6.6330
51210.167.6.64/27210.167.6.65 to 210.167.6.94210.167.6.9530
52210.167.6.96/27210.167.6.97 to 210.167.6.126210.167.6.12730
53210.167.6.128/27210.167.6.129 to 210.167.6.158210.167.6.15930
54210.167.6.160/27210.167.6.161 to 210.167.6.190210.167.6.19130
55210.167.6.192/27210.167.6.193 to 210.167.6.222210.167.6.22330
56210.167.6.224/27210.167.6.225 to 210.167.6.254210.167.6.25530
57210.167.7.0/27210.167.7.1 to 210.167.7.30210.167.7.3130
58210.167.7.32/27210.167.7.33 to 210.167.7.62210.167.7.6330
59210.167.7.64/27210.167.7.65 to 210.167.7.94210.167.7.9530
60210.167.7.96/27210.167.7.97 to 210.167.7.126210.167.7.12730
61210.167.7.128/27210.167.7.129 to 210.167.7.158210.167.7.15930
62210.167.7.160/27210.167.7.161 to 210.167.7.190210.167.7.19130
63210.167.7.192/27210.167.7.193 to 210.167.7.222210.167.7.22330
64210.167.7.224/27210.167.7.225 to 210.167.7.254210.167.7.25530
65210.167.8.0/27210.167.8.1 to 210.167.8.30210.167.8.3130
66210.167.8.32/27210.167.8.33 to 210.167.8.62210.167.8.6330
67210.167.8.64/27210.167.8.65 to 210.167.8.94210.167.8.9530
68210.167.8.96/27210.167.8.97 to 210.167.8.126210.167.8.12730
69210.167.8.128/27210.167.8.129 to 210.167.8.158210.167.8.15930
70210.167.8.160/27210.167.8.161 to 210.167.8.190210.167.8.19130
71210.167.8.192/27210.167.8.193 to 210.167.8.222210.167.8.22330
72210.167.8.224/27210.167.8.225 to 210.167.8.254210.167.8.25530
73210.167.9.0/27210.167.9.1 to 210.167.9.30210.167.9.3130
74210.167.9.32/27210.167.9.33 to 210.167.9.62210.167.9.6330
75210.167.9.64/27210.167.9.65 to 210.167.9.94210.167.9.9530
76210.167.9.96/27210.167.9.97 to 210.167.9.126210.167.9.12730
77210.167.9.128/27210.167.9.129 to 210.167.9.158210.167.9.15930
78210.167.9.160/27210.167.9.161 to 210.167.9.190210.167.9.19130
79210.167.9.192/27210.167.9.193 to 210.167.9.222210.167.9.22330
80210.167.9.224/27210.167.9.225 to 210.167.9.254210.167.9.25530
81210.167.10.0/27210.167.10.1 to 210.167.10.30210.167.10.3130
82210.167.10.32/27210.167.10.33 to 210.167.10.62210.167.10.6330
83210.167.10.64/27210.167.10.65 to 210.167.10.94210.167.10.9530
84210.167.10.96/27210.167.10.97 to 210.167.10.126210.167.10.12730
85210.167.10.128/27210.167.10.129 to 210.167.10.158210.167.10.15930
86210.167.10.160/27210.167.10.161 to 210.167.10.190210.167.10.19130
87210.167.10.192/27210.167.10.193 to 210.167.10.222210.167.10.22330
88210.167.10.224/27210.167.10.225 to 210.167.10.254210.167.10.25530
89210.167.11.0/27210.167.11.1 to 210.167.11.30210.167.11.3130
90210.167.11.32/27210.167.11.33 to 210.167.11.62210.167.11.6330
91210.167.11.64/27210.167.11.65 to 210.167.11.94210.167.11.9530
92210.167.11.96/27210.167.11.97 to 210.167.11.126210.167.11.12730
93210.167.11.128/27210.167.11.129 to 210.167.11.158210.167.11.15930
94210.167.11.160/27210.167.11.161 to 210.167.11.190210.167.11.19130
95210.167.11.192/27210.167.11.193 to 210.167.11.222210.167.11.22330
96210.167.11.224/27210.167.11.225 to 210.167.11.254210.167.11.25530
97210.167.12.0/27210.167.12.1 to 210.167.12.30210.167.12.3130
98210.167.12.32/27210.167.12.33 to 210.167.12.62210.167.12.6330
99210.167.12.64/27210.167.12.65 to 210.167.12.94210.167.12.9530
100210.167.12.96/27210.167.12.97 to 210.167.12.126210.167.12.12730
101210.167.12.128/27210.167.12.129 to 210.167.12.158210.167.12.15930
102210.167.12.160/27210.167.12.161 to 210.167.12.190210.167.12.19130
103210.167.12.192/27210.167.12.193 to 210.167.12.222210.167.12.22330
104210.167.12.224/27210.167.12.225 to 210.167.12.254210.167.12.25530
105210.167.13.0/27210.167.13.1 to 210.167.13.30210.167.13.3130
106210.167.13.32/27210.167.13.33 to 210.167.13.62210.167.13.6330
107210.167.13.64/27210.167.13.65 to 210.167.13.94210.167.13.9530
108210.167.13.96/27210.167.13.97 to 210.167.13.126210.167.13.12730
109210.167.13.128/27210.167.13.129 to 210.167.13.158210.167.13.15930
110210.167.13.160/27210.167.13.161 to 210.167.13.190210.167.13.19130
111210.167.13.192/27210.167.13.193 to 210.167.13.222210.167.13.22330
112210.167.13.224/27210.167.13.225 to 210.167.13.254210.167.13.25530
113210.167.14.0/27210.167.14.1 to 210.167.14.30210.167.14.3130
114210.167.14.32/27210.167.14.33 to 210.167.14.62210.167.14.6330
115210.167.14.64/27210.167.14.65 to 210.167.14.94210.167.14.9530
116210.167.14.96/27210.167.14.97 to 210.167.14.126210.167.14.12730
117210.167.14.128/27210.167.14.129 to 210.167.14.158210.167.14.15930
118210.167.14.160/27210.167.14.161 to 210.167.14.190210.167.14.19130
119210.167.14.192/27210.167.14.193 to 210.167.14.222210.167.14.22330
120210.167.14.224/27210.167.14.225 to 210.167.14.254210.167.14.25530
121210.167.15.0/27210.167.15.1 to 210.167.15.30210.167.15.3130
122210.167.15.32/27210.167.15.33 to 210.167.15.62210.167.15.6330
123210.167.15.64/27210.167.15.65 to 210.167.15.94210.167.15.9530
124210.167.15.96/27210.167.15.97 to 210.167.15.126210.167.15.12730
125210.167.15.128/27210.167.15.129 to 210.167.15.158210.167.15.15930
126210.167.15.160/27210.167.15.161 to 210.167.15.190210.167.15.19130
127210.167.15.192/27210.167.15.193 to 210.167.15.222210.167.15.22330
128210.167.15.224/27210.167.15.225 to 210.167.15.254210.167.15.25530
129210.167.16.0/27210.167.16.1 to 210.167.16.30210.167.16.3130
130210.167.16.32/27210.167.16.33 to 210.167.16.62210.167.16.6330
131210.167.16.64/27210.167.16.65 to 210.167.16.94210.167.16.9530
132210.167.16.96/27210.167.16.97 to 210.167.16.126210.167.16.12730
133210.167.16.128/27210.167.16.129 to 210.167.16.158210.167.16.15930
134210.167.16.160/27210.167.16.161 to 210.167.16.190210.167.16.19130
135210.167.16.192/27210.167.16.193 to 210.167.16.222210.167.16.22330
136210.167.16.224/27210.167.16.225 to 210.167.16.254210.167.16.25530
137210.167.17.0/27210.167.17.1 to 210.167.17.30210.167.17.3130
138210.167.17.32/27210.167.17.33 to 210.167.17.62210.167.17.6330
139210.167.17.64/27210.167.17.65 to 210.167.17.94210.167.17.9530
140210.167.17.96/27210.167.17.97 to 210.167.17.126210.167.17.12730
141210.167.17.128/27210.167.17.129 to 210.167.17.158210.167.17.15930
142210.167.17.160/27210.167.17.161 to 210.167.17.190210.167.17.19130
143210.167.17.192/27210.167.17.193 to 210.167.17.222210.167.17.22330
144210.167.17.224/27210.167.17.225 to 210.167.17.254210.167.17.25530
145210.167.18.0/27210.167.18.1 to 210.167.18.30210.167.18.3130
146210.167.18.32/27210.167.18.33 to 210.167.18.62210.167.18.6330
147210.167.18.64/27210.167.18.65 to 210.167.18.94210.167.18.9530
148210.167.18.96/27210.167.18.97 to 210.167.18.126210.167.18.12730
149210.167.18.128/27210.167.18.129 to 210.167.18.158210.167.18.15930
150210.167.18.160/27210.167.18.161 to 210.167.18.190210.167.18.19130
151210.167.18.192/27210.167.18.193 to 210.167.18.222210.167.18.22330
152210.167.18.224/27210.167.18.225 to 210.167.18.254210.167.18.25530
153210.167.19.0/27210.167.19.1 to 210.167.19.30210.167.19.3130
154210.167.19.32/27210.167.19.33 to 210.167.19.62210.167.19.6330
155210.167.19.64/27210.167.19.65 to 210.167.19.94210.167.19.9530
156210.167.19.96/27210.167.19.97 to 210.167.19.126210.167.19.12730
157210.167.19.128/27210.167.19.129 to 210.167.19.158210.167.19.15930
158210.167.19.160/27210.167.19.161 to 210.167.19.190210.167.19.19130
159210.167.19.192/27210.167.19.193 to 210.167.19.222210.167.19.22330
160210.167.19.224/27210.167.19.225 to 210.167.19.254210.167.19.25530
161210.167.20.0/27210.167.20.1 to 210.167.20.30210.167.20.3130
162210.167.20.32/27210.167.20.33 to 210.167.20.62210.167.20.6330
163210.167.20.64/27210.167.20.65 to 210.167.20.94210.167.20.9530
164210.167.20.96/27210.167.20.97 to 210.167.20.126210.167.20.12730
165210.167.20.128/27210.167.20.129 to 210.167.20.158210.167.20.15930
166210.167.20.160/27210.167.20.161 to 210.167.20.190210.167.20.19130
167210.167.20.192/27210.167.20.193 to 210.167.20.222210.167.20.22330
168210.167.20.224/27210.167.20.225 to 210.167.20.254210.167.20.25530
169210.167.21.0/27210.167.21.1 to 210.167.21.30210.167.21.3130
170210.167.21.32/27210.167.21.33 to 210.167.21.62210.167.21.6330
171210.167.21.64/27210.167.21.65 to 210.167.21.94210.167.21.9530
172210.167.21.96/27210.167.21.97 to 210.167.21.126210.167.21.12730
173210.167.21.128/27210.167.21.129 to 210.167.21.158210.167.21.15930
174210.167.21.160/27210.167.21.161 to 210.167.21.190210.167.21.19130
175210.167.21.192/27210.167.21.193 to 210.167.21.222210.167.21.22330
176210.167.21.224/27210.167.21.225 to 210.167.21.254210.167.21.25530
177210.167.22.0/27210.167.22.1 to 210.167.22.30210.167.22.3130
178210.167.22.32/27210.167.22.33 to 210.167.22.62210.167.22.6330
179210.167.22.64/27210.167.22.65 to 210.167.22.94210.167.22.9530
180210.167.22.96/27210.167.22.97 to 210.167.22.126210.167.22.12730
181210.167.22.128/27210.167.22.129 to 210.167.22.158210.167.22.15930
182210.167.22.160/27210.167.22.161 to 210.167.22.190210.167.22.19130
183210.167.22.192/27210.167.22.193 to 210.167.22.222210.167.22.22330
184210.167.22.224/27210.167.22.225 to 210.167.22.254210.167.22.25530
185210.167.23.0/27210.167.23.1 to 210.167.23.30210.167.23.3130
186210.167.23.32/27210.167.23.33 to 210.167.23.62210.167.23.6330
187210.167.23.64/27210.167.23.65 to 210.167.23.94210.167.23.9530
188210.167.23.96/27210.167.23.97 to 210.167.23.126210.167.23.12730
189210.167.23.128/27210.167.23.129 to 210.167.23.158210.167.23.15930
190210.167.23.160/27210.167.23.161 to 210.167.23.190210.167.23.19130
191210.167.23.192/27210.167.23.193 to 210.167.23.222210.167.23.22330
192210.167.23.224/27210.167.23.225 to 210.167.23.254210.167.23.25530
193210.167.24.0/27210.167.24.1 to 210.167.24.30210.167.24.3130
194210.167.24.32/27210.167.24.33 to 210.167.24.62210.167.24.6330
195210.167.24.64/27210.167.24.65 to 210.167.24.94210.167.24.9530
196210.167.24.96/27210.167.24.97 to 210.167.24.126210.167.24.12730
197210.167.24.128/27210.167.24.129 to 210.167.24.158210.167.24.15930
198210.167.24.160/27210.167.24.161 to 210.167.24.190210.167.24.19130
199210.167.24.192/27210.167.24.193 to 210.167.24.222210.167.24.22330
200210.167.24.224/27210.167.24.225 to 210.167.24.254210.167.24.25530
201210.167.25.0/27210.167.25.1 to 210.167.25.30210.167.25.3130
202210.167.25.32/27210.167.25.33 to 210.167.25.62210.167.25.6330
203210.167.25.64/27210.167.25.65 to 210.167.25.94210.167.25.9530
204210.167.25.96/27210.167.25.97 to 210.167.25.126210.167.25.12730
205210.167.25.128/27210.167.25.129 to 210.167.25.158210.167.25.15930
206210.167.25.160/27210.167.25.161 to 210.167.25.190210.167.25.19130
207210.167.25.192/27210.167.25.193 to 210.167.25.222210.167.25.22330
208210.167.25.224/27210.167.25.225 to 210.167.25.254210.167.25.25530
209210.167.26.0/27210.167.26.1 to 210.167.26.30210.167.26.3130
210210.167.26.32/27210.167.26.33 to 210.167.26.62210.167.26.6330
211210.167.26.64/27210.167.26.65 to 210.167.26.94210.167.26.9530
212210.167.26.96/27210.167.26.97 to 210.167.26.126210.167.26.12730
213210.167.26.128/27210.167.26.129 to 210.167.26.158210.167.26.15930
214210.167.26.160/27210.167.26.161 to 210.167.26.190210.167.26.19130
215210.167.26.192/27210.167.26.193 to 210.167.26.222210.167.26.22330
216210.167.26.224/27210.167.26.225 to 210.167.26.254210.167.26.25530
217210.167.27.0/27210.167.27.1 to 210.167.27.30210.167.27.3130
218210.167.27.32/27210.167.27.33 to 210.167.27.62210.167.27.6330
219210.167.27.64/27210.167.27.65 to 210.167.27.94210.167.27.9530
220210.167.27.96/27210.167.27.97 to 210.167.27.126210.167.27.12730
221210.167.27.128/27210.167.27.129 to 210.167.27.158210.167.27.15930
222210.167.27.160/27210.167.27.161 to 210.167.27.190210.167.27.19130
223210.167.27.192/27210.167.27.193 to 210.167.27.222210.167.27.22330
224210.167.27.224/27210.167.27.225 to 210.167.27.254210.167.27.25530
225210.167.28.0/27210.167.28.1 to 210.167.28.30210.167.28.3130
226210.167.28.32/27210.167.28.33 to 210.167.28.62210.167.28.6330
227210.167.28.64/27210.167.28.65 to 210.167.28.94210.167.28.9530
228210.167.28.96/27210.167.28.97 to 210.167.28.126210.167.28.12730
229210.167.28.128/27210.167.28.129 to 210.167.28.158210.167.28.15930
230210.167.28.160/27210.167.28.161 to 210.167.28.190210.167.28.19130
231210.167.28.192/27210.167.28.193 to 210.167.28.222210.167.28.22330
232210.167.28.224/27210.167.28.225 to 210.167.28.254210.167.28.25530
233210.167.29.0/27210.167.29.1 to 210.167.29.30210.167.29.3130
234210.167.29.32/27210.167.29.33 to 210.167.29.62210.167.29.6330
235210.167.29.64/27210.167.29.65 to 210.167.29.94210.167.29.9530
236210.167.29.96/27210.167.29.97 to 210.167.29.126210.167.29.12730
237210.167.29.128/27210.167.29.129 to 210.167.29.158210.167.29.15930
238210.167.29.160/27210.167.29.161 to 210.167.29.190210.167.29.19130
239210.167.29.192/27210.167.29.193 to 210.167.29.222210.167.29.22330
240210.167.29.224/27210.167.29.225 to 210.167.29.254210.167.29.25530
241210.167.30.0/27210.167.30.1 to 210.167.30.30210.167.30.3130
242210.167.30.32/27210.167.30.33 to 210.167.30.62210.167.30.6330
243210.167.30.64/27210.167.30.65 to 210.167.30.94210.167.30.9530
244210.167.30.96/27210.167.30.97 to 210.167.30.126210.167.30.12730
245210.167.30.128/27210.167.30.129 to 210.167.30.158210.167.30.15930
246210.167.30.160/27210.167.30.161 to 210.167.30.190210.167.30.19130
247210.167.30.192/27210.167.30.193 to 210.167.30.222210.167.30.22330
248210.167.30.224/27210.167.30.225 to 210.167.30.254210.167.30.25530
249210.167.31.0/27210.167.31.1 to 210.167.31.30210.167.31.3130
250210.167.31.32/27210.167.31.33 to 210.167.31.62210.167.31.6330
251210.167.31.64/27210.167.31.65 to 210.167.31.94210.167.31.9530
252210.167.31.96/27210.167.31.97 to 210.167.31.126210.167.31.12730
253210.167.31.128/27210.167.31.129 to 210.167.31.158210.167.31.15930
254210.167.31.160/27210.167.31.161 to 210.167.31.190210.167.31.19130
255210.167.31.192/27210.167.31.193 to 210.167.31.222210.167.31.22330
256210.167.31.224/27210.167.31.225 to 210.167.31.254210.167.31.25530

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.