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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/28
/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 4,096 subnets of /28; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1210.167.0.0/28210.167.0.1 to 210.167.0.14210.167.0.1514
2210.167.0.16/28210.167.0.17 to 210.167.0.30210.167.0.3114
3210.167.0.32/28210.167.0.33 to 210.167.0.46210.167.0.4714
4210.167.0.48/28210.167.0.49 to 210.167.0.62210.167.0.6314
5210.167.0.64/28210.167.0.65 to 210.167.0.78210.167.0.7914
6210.167.0.80/28210.167.0.81 to 210.167.0.94210.167.0.9514
7210.167.0.96/28210.167.0.97 to 210.167.0.110210.167.0.11114
8210.167.0.112/28210.167.0.113 to 210.167.0.126210.167.0.12714
9210.167.0.128/28210.167.0.129 to 210.167.0.142210.167.0.14314
10210.167.0.144/28210.167.0.145 to 210.167.0.158210.167.0.15914
11210.167.0.160/28210.167.0.161 to 210.167.0.174210.167.0.17514
12210.167.0.176/28210.167.0.177 to 210.167.0.190210.167.0.19114
13210.167.0.192/28210.167.0.193 to 210.167.0.206210.167.0.20714
14210.167.0.208/28210.167.0.209 to 210.167.0.222210.167.0.22314
15210.167.0.224/28210.167.0.225 to 210.167.0.238210.167.0.23914
16210.167.0.240/28210.167.0.241 to 210.167.0.254210.167.0.25514
17210.167.1.0/28210.167.1.1 to 210.167.1.14210.167.1.1514
18210.167.1.16/28210.167.1.17 to 210.167.1.30210.167.1.3114
19210.167.1.32/28210.167.1.33 to 210.167.1.46210.167.1.4714
20210.167.1.48/28210.167.1.49 to 210.167.1.62210.167.1.6314
21210.167.1.64/28210.167.1.65 to 210.167.1.78210.167.1.7914
22210.167.1.80/28210.167.1.81 to 210.167.1.94210.167.1.9514
23210.167.1.96/28210.167.1.97 to 210.167.1.110210.167.1.11114
24210.167.1.112/28210.167.1.113 to 210.167.1.126210.167.1.12714
25210.167.1.128/28210.167.1.129 to 210.167.1.142210.167.1.14314
26210.167.1.144/28210.167.1.145 to 210.167.1.158210.167.1.15914
27210.167.1.160/28210.167.1.161 to 210.167.1.174210.167.1.17514
28210.167.1.176/28210.167.1.177 to 210.167.1.190210.167.1.19114
29210.167.1.192/28210.167.1.193 to 210.167.1.206210.167.1.20714
30210.167.1.208/28210.167.1.209 to 210.167.1.222210.167.1.22314
31210.167.1.224/28210.167.1.225 to 210.167.1.238210.167.1.23914
32210.167.1.240/28210.167.1.241 to 210.167.1.254210.167.1.25514
33210.167.2.0/28210.167.2.1 to 210.167.2.14210.167.2.1514
34210.167.2.16/28210.167.2.17 to 210.167.2.30210.167.2.3114
35210.167.2.32/28210.167.2.33 to 210.167.2.46210.167.2.4714
36210.167.2.48/28210.167.2.49 to 210.167.2.62210.167.2.6314
37210.167.2.64/28210.167.2.65 to 210.167.2.78210.167.2.7914
38210.167.2.80/28210.167.2.81 to 210.167.2.94210.167.2.9514
39210.167.2.96/28210.167.2.97 to 210.167.2.110210.167.2.11114
40210.167.2.112/28210.167.2.113 to 210.167.2.126210.167.2.12714
41210.167.2.128/28210.167.2.129 to 210.167.2.142210.167.2.14314
42210.167.2.144/28210.167.2.145 to 210.167.2.158210.167.2.15914
43210.167.2.160/28210.167.2.161 to 210.167.2.174210.167.2.17514
44210.167.2.176/28210.167.2.177 to 210.167.2.190210.167.2.19114
45210.167.2.192/28210.167.2.193 to 210.167.2.206210.167.2.20714
46210.167.2.208/28210.167.2.209 to 210.167.2.222210.167.2.22314
47210.167.2.224/28210.167.2.225 to 210.167.2.238210.167.2.23914
48210.167.2.240/28210.167.2.241 to 210.167.2.254210.167.2.25514
49210.167.3.0/28210.167.3.1 to 210.167.3.14210.167.3.1514
50210.167.3.16/28210.167.3.17 to 210.167.3.30210.167.3.3114
51210.167.3.32/28210.167.3.33 to 210.167.3.46210.167.3.4714
52210.167.3.48/28210.167.3.49 to 210.167.3.62210.167.3.6314
53210.167.3.64/28210.167.3.65 to 210.167.3.78210.167.3.7914
54210.167.3.80/28210.167.3.81 to 210.167.3.94210.167.3.9514
55210.167.3.96/28210.167.3.97 to 210.167.3.110210.167.3.11114
56210.167.3.112/28210.167.3.113 to 210.167.3.126210.167.3.12714
57210.167.3.128/28210.167.3.129 to 210.167.3.142210.167.3.14314
58210.167.3.144/28210.167.3.145 to 210.167.3.158210.167.3.15914
59210.167.3.160/28210.167.3.161 to 210.167.3.174210.167.3.17514
60210.167.3.176/28210.167.3.177 to 210.167.3.190210.167.3.19114
61210.167.3.192/28210.167.3.193 to 210.167.3.206210.167.3.20714
62210.167.3.208/28210.167.3.209 to 210.167.3.222210.167.3.22314
63210.167.3.224/28210.167.3.225 to 210.167.3.238210.167.3.23914
64210.167.3.240/28210.167.3.241 to 210.167.3.254210.167.3.25514
65210.167.4.0/28210.167.4.1 to 210.167.4.14210.167.4.1514
66210.167.4.16/28210.167.4.17 to 210.167.4.30210.167.4.3114
67210.167.4.32/28210.167.4.33 to 210.167.4.46210.167.4.4714
68210.167.4.48/28210.167.4.49 to 210.167.4.62210.167.4.6314
69210.167.4.64/28210.167.4.65 to 210.167.4.78210.167.4.7914
70210.167.4.80/28210.167.4.81 to 210.167.4.94210.167.4.9514
71210.167.4.96/28210.167.4.97 to 210.167.4.110210.167.4.11114
72210.167.4.112/28210.167.4.113 to 210.167.4.126210.167.4.12714
73210.167.4.128/28210.167.4.129 to 210.167.4.142210.167.4.14314
74210.167.4.144/28210.167.4.145 to 210.167.4.158210.167.4.15914
75210.167.4.160/28210.167.4.161 to 210.167.4.174210.167.4.17514
76210.167.4.176/28210.167.4.177 to 210.167.4.190210.167.4.19114
77210.167.4.192/28210.167.4.193 to 210.167.4.206210.167.4.20714
78210.167.4.208/28210.167.4.209 to 210.167.4.222210.167.4.22314
79210.167.4.224/28210.167.4.225 to 210.167.4.238210.167.4.23914
80210.167.4.240/28210.167.4.241 to 210.167.4.254210.167.4.25514
81210.167.5.0/28210.167.5.1 to 210.167.5.14210.167.5.1514
82210.167.5.16/28210.167.5.17 to 210.167.5.30210.167.5.3114
83210.167.5.32/28210.167.5.33 to 210.167.5.46210.167.5.4714
84210.167.5.48/28210.167.5.49 to 210.167.5.62210.167.5.6314
85210.167.5.64/28210.167.5.65 to 210.167.5.78210.167.5.7914
86210.167.5.80/28210.167.5.81 to 210.167.5.94210.167.5.9514
87210.167.5.96/28210.167.5.97 to 210.167.5.110210.167.5.11114
88210.167.5.112/28210.167.5.113 to 210.167.5.126210.167.5.12714
89210.167.5.128/28210.167.5.129 to 210.167.5.142210.167.5.14314
90210.167.5.144/28210.167.5.145 to 210.167.5.158210.167.5.15914
91210.167.5.160/28210.167.5.161 to 210.167.5.174210.167.5.17514
92210.167.5.176/28210.167.5.177 to 210.167.5.190210.167.5.19114
93210.167.5.192/28210.167.5.193 to 210.167.5.206210.167.5.20714
94210.167.5.208/28210.167.5.209 to 210.167.5.222210.167.5.22314
95210.167.5.224/28210.167.5.225 to 210.167.5.238210.167.5.23914
96210.167.5.240/28210.167.5.241 to 210.167.5.254210.167.5.25514
97210.167.6.0/28210.167.6.1 to 210.167.6.14210.167.6.1514
98210.167.6.16/28210.167.6.17 to 210.167.6.30210.167.6.3114
99210.167.6.32/28210.167.6.33 to 210.167.6.46210.167.6.4714
100210.167.6.48/28210.167.6.49 to 210.167.6.62210.167.6.6314
101210.167.6.64/28210.167.6.65 to 210.167.6.78210.167.6.7914
102210.167.6.80/28210.167.6.81 to 210.167.6.94210.167.6.9514
103210.167.6.96/28210.167.6.97 to 210.167.6.110210.167.6.11114
104210.167.6.112/28210.167.6.113 to 210.167.6.126210.167.6.12714
105210.167.6.128/28210.167.6.129 to 210.167.6.142210.167.6.14314
106210.167.6.144/28210.167.6.145 to 210.167.6.158210.167.6.15914
107210.167.6.160/28210.167.6.161 to 210.167.6.174210.167.6.17514
108210.167.6.176/28210.167.6.177 to 210.167.6.190210.167.6.19114
109210.167.6.192/28210.167.6.193 to 210.167.6.206210.167.6.20714
110210.167.6.208/28210.167.6.209 to 210.167.6.222210.167.6.22314
111210.167.6.224/28210.167.6.225 to 210.167.6.238210.167.6.23914
112210.167.6.240/28210.167.6.241 to 210.167.6.254210.167.6.25514
113210.167.7.0/28210.167.7.1 to 210.167.7.14210.167.7.1514
114210.167.7.16/28210.167.7.17 to 210.167.7.30210.167.7.3114
115210.167.7.32/28210.167.7.33 to 210.167.7.46210.167.7.4714
116210.167.7.48/28210.167.7.49 to 210.167.7.62210.167.7.6314
117210.167.7.64/28210.167.7.65 to 210.167.7.78210.167.7.7914
118210.167.7.80/28210.167.7.81 to 210.167.7.94210.167.7.9514
119210.167.7.96/28210.167.7.97 to 210.167.7.110210.167.7.11114
120210.167.7.112/28210.167.7.113 to 210.167.7.126210.167.7.12714
121210.167.7.128/28210.167.7.129 to 210.167.7.142210.167.7.14314
122210.167.7.144/28210.167.7.145 to 210.167.7.158210.167.7.15914
123210.167.7.160/28210.167.7.161 to 210.167.7.174210.167.7.17514
124210.167.7.176/28210.167.7.177 to 210.167.7.190210.167.7.19114
125210.167.7.192/28210.167.7.193 to 210.167.7.206210.167.7.20714
126210.167.7.208/28210.167.7.209 to 210.167.7.222210.167.7.22314
127210.167.7.224/28210.167.7.225 to 210.167.7.238210.167.7.23914
128210.167.7.240/28210.167.7.241 to 210.167.7.254210.167.7.25514
129210.167.8.0/28210.167.8.1 to 210.167.8.14210.167.8.1514
130210.167.8.16/28210.167.8.17 to 210.167.8.30210.167.8.3114
131210.167.8.32/28210.167.8.33 to 210.167.8.46210.167.8.4714
132210.167.8.48/28210.167.8.49 to 210.167.8.62210.167.8.6314
133210.167.8.64/28210.167.8.65 to 210.167.8.78210.167.8.7914
134210.167.8.80/28210.167.8.81 to 210.167.8.94210.167.8.9514
135210.167.8.96/28210.167.8.97 to 210.167.8.110210.167.8.11114
136210.167.8.112/28210.167.8.113 to 210.167.8.126210.167.8.12714
137210.167.8.128/28210.167.8.129 to 210.167.8.142210.167.8.14314
138210.167.8.144/28210.167.8.145 to 210.167.8.158210.167.8.15914
139210.167.8.160/28210.167.8.161 to 210.167.8.174210.167.8.17514
140210.167.8.176/28210.167.8.177 to 210.167.8.190210.167.8.19114
141210.167.8.192/28210.167.8.193 to 210.167.8.206210.167.8.20714
142210.167.8.208/28210.167.8.209 to 210.167.8.222210.167.8.22314
143210.167.8.224/28210.167.8.225 to 210.167.8.238210.167.8.23914
144210.167.8.240/28210.167.8.241 to 210.167.8.254210.167.8.25514
145210.167.9.0/28210.167.9.1 to 210.167.9.14210.167.9.1514
146210.167.9.16/28210.167.9.17 to 210.167.9.30210.167.9.3114
147210.167.9.32/28210.167.9.33 to 210.167.9.46210.167.9.4714
148210.167.9.48/28210.167.9.49 to 210.167.9.62210.167.9.6314
149210.167.9.64/28210.167.9.65 to 210.167.9.78210.167.9.7914
150210.167.9.80/28210.167.9.81 to 210.167.9.94210.167.9.9514
151210.167.9.96/28210.167.9.97 to 210.167.9.110210.167.9.11114
152210.167.9.112/28210.167.9.113 to 210.167.9.126210.167.9.12714
153210.167.9.128/28210.167.9.129 to 210.167.9.142210.167.9.14314
154210.167.9.144/28210.167.9.145 to 210.167.9.158210.167.9.15914
155210.167.9.160/28210.167.9.161 to 210.167.9.174210.167.9.17514
156210.167.9.176/28210.167.9.177 to 210.167.9.190210.167.9.19114
157210.167.9.192/28210.167.9.193 to 210.167.9.206210.167.9.20714
158210.167.9.208/28210.167.9.209 to 210.167.9.222210.167.9.22314
159210.167.9.224/28210.167.9.225 to 210.167.9.238210.167.9.23914
160210.167.9.240/28210.167.9.241 to 210.167.9.254210.167.9.25514
161210.167.10.0/28210.167.10.1 to 210.167.10.14210.167.10.1514
162210.167.10.16/28210.167.10.17 to 210.167.10.30210.167.10.3114
163210.167.10.32/28210.167.10.33 to 210.167.10.46210.167.10.4714
164210.167.10.48/28210.167.10.49 to 210.167.10.62210.167.10.6314
165210.167.10.64/28210.167.10.65 to 210.167.10.78210.167.10.7914
166210.167.10.80/28210.167.10.81 to 210.167.10.94210.167.10.9514
167210.167.10.96/28210.167.10.97 to 210.167.10.110210.167.10.11114
168210.167.10.112/28210.167.10.113 to 210.167.10.126210.167.10.12714
169210.167.10.128/28210.167.10.129 to 210.167.10.142210.167.10.14314
170210.167.10.144/28210.167.10.145 to 210.167.10.158210.167.10.15914
171210.167.10.160/28210.167.10.161 to 210.167.10.174210.167.10.17514
172210.167.10.176/28210.167.10.177 to 210.167.10.190210.167.10.19114
173210.167.10.192/28210.167.10.193 to 210.167.10.206210.167.10.20714
174210.167.10.208/28210.167.10.209 to 210.167.10.222210.167.10.22314
175210.167.10.224/28210.167.10.225 to 210.167.10.238210.167.10.23914
176210.167.10.240/28210.167.10.241 to 210.167.10.254210.167.10.25514
177210.167.11.0/28210.167.11.1 to 210.167.11.14210.167.11.1514
178210.167.11.16/28210.167.11.17 to 210.167.11.30210.167.11.3114
179210.167.11.32/28210.167.11.33 to 210.167.11.46210.167.11.4714
180210.167.11.48/28210.167.11.49 to 210.167.11.62210.167.11.6314
181210.167.11.64/28210.167.11.65 to 210.167.11.78210.167.11.7914
182210.167.11.80/28210.167.11.81 to 210.167.11.94210.167.11.9514
183210.167.11.96/28210.167.11.97 to 210.167.11.110210.167.11.11114
184210.167.11.112/28210.167.11.113 to 210.167.11.126210.167.11.12714
185210.167.11.128/28210.167.11.129 to 210.167.11.142210.167.11.14314
186210.167.11.144/28210.167.11.145 to 210.167.11.158210.167.11.15914
187210.167.11.160/28210.167.11.161 to 210.167.11.174210.167.11.17514
188210.167.11.176/28210.167.11.177 to 210.167.11.190210.167.11.19114
189210.167.11.192/28210.167.11.193 to 210.167.11.206210.167.11.20714
190210.167.11.208/28210.167.11.209 to 210.167.11.222210.167.11.22314
191210.167.11.224/28210.167.11.225 to 210.167.11.238210.167.11.23914
192210.167.11.240/28210.167.11.241 to 210.167.11.254210.167.11.25514
193210.167.12.0/28210.167.12.1 to 210.167.12.14210.167.12.1514
194210.167.12.16/28210.167.12.17 to 210.167.12.30210.167.12.3114
195210.167.12.32/28210.167.12.33 to 210.167.12.46210.167.12.4714
196210.167.12.48/28210.167.12.49 to 210.167.12.62210.167.12.6314
197210.167.12.64/28210.167.12.65 to 210.167.12.78210.167.12.7914
198210.167.12.80/28210.167.12.81 to 210.167.12.94210.167.12.9514
199210.167.12.96/28210.167.12.97 to 210.167.12.110210.167.12.11114
200210.167.12.112/28210.167.12.113 to 210.167.12.126210.167.12.12714
201210.167.12.128/28210.167.12.129 to 210.167.12.142210.167.12.14314
202210.167.12.144/28210.167.12.145 to 210.167.12.158210.167.12.15914
203210.167.12.160/28210.167.12.161 to 210.167.12.174210.167.12.17514
204210.167.12.176/28210.167.12.177 to 210.167.12.190210.167.12.19114
205210.167.12.192/28210.167.12.193 to 210.167.12.206210.167.12.20714
206210.167.12.208/28210.167.12.209 to 210.167.12.222210.167.12.22314
207210.167.12.224/28210.167.12.225 to 210.167.12.238210.167.12.23914
208210.167.12.240/28210.167.12.241 to 210.167.12.254210.167.12.25514
209210.167.13.0/28210.167.13.1 to 210.167.13.14210.167.13.1514
210210.167.13.16/28210.167.13.17 to 210.167.13.30210.167.13.3114
211210.167.13.32/28210.167.13.33 to 210.167.13.46210.167.13.4714
212210.167.13.48/28210.167.13.49 to 210.167.13.62210.167.13.6314
213210.167.13.64/28210.167.13.65 to 210.167.13.78210.167.13.7914
214210.167.13.80/28210.167.13.81 to 210.167.13.94210.167.13.9514
215210.167.13.96/28210.167.13.97 to 210.167.13.110210.167.13.11114
216210.167.13.112/28210.167.13.113 to 210.167.13.126210.167.13.12714
217210.167.13.128/28210.167.13.129 to 210.167.13.142210.167.13.14314
218210.167.13.144/28210.167.13.145 to 210.167.13.158210.167.13.15914
219210.167.13.160/28210.167.13.161 to 210.167.13.174210.167.13.17514
220210.167.13.176/28210.167.13.177 to 210.167.13.190210.167.13.19114
221210.167.13.192/28210.167.13.193 to 210.167.13.206210.167.13.20714
222210.167.13.208/28210.167.13.209 to 210.167.13.222210.167.13.22314
223210.167.13.224/28210.167.13.225 to 210.167.13.238210.167.13.23914
224210.167.13.240/28210.167.13.241 to 210.167.13.254210.167.13.25514
225210.167.14.0/28210.167.14.1 to 210.167.14.14210.167.14.1514
226210.167.14.16/28210.167.14.17 to 210.167.14.30210.167.14.3114
227210.167.14.32/28210.167.14.33 to 210.167.14.46210.167.14.4714
228210.167.14.48/28210.167.14.49 to 210.167.14.62210.167.14.6314
229210.167.14.64/28210.167.14.65 to 210.167.14.78210.167.14.7914
230210.167.14.80/28210.167.14.81 to 210.167.14.94210.167.14.9514
231210.167.14.96/28210.167.14.97 to 210.167.14.110210.167.14.11114
232210.167.14.112/28210.167.14.113 to 210.167.14.126210.167.14.12714
233210.167.14.128/28210.167.14.129 to 210.167.14.142210.167.14.14314
234210.167.14.144/28210.167.14.145 to 210.167.14.158210.167.14.15914
235210.167.14.160/28210.167.14.161 to 210.167.14.174210.167.14.17514
236210.167.14.176/28210.167.14.177 to 210.167.14.190210.167.14.19114
237210.167.14.192/28210.167.14.193 to 210.167.14.206210.167.14.20714
238210.167.14.208/28210.167.14.209 to 210.167.14.222210.167.14.22314
239210.167.14.224/28210.167.14.225 to 210.167.14.238210.167.14.23914
240210.167.14.240/28210.167.14.241 to 210.167.14.254210.167.14.25514
241210.167.15.0/28210.167.15.1 to 210.167.15.14210.167.15.1514
242210.167.15.16/28210.167.15.17 to 210.167.15.30210.167.15.3114
243210.167.15.32/28210.167.15.33 to 210.167.15.46210.167.15.4714
244210.167.15.48/28210.167.15.49 to 210.167.15.62210.167.15.6314
245210.167.15.64/28210.167.15.65 to 210.167.15.78210.167.15.7914
246210.167.15.80/28210.167.15.81 to 210.167.15.94210.167.15.9514
247210.167.15.96/28210.167.15.97 to 210.167.15.110210.167.15.11114
248210.167.15.112/28210.167.15.113 to 210.167.15.126210.167.15.12714
249210.167.15.128/28210.167.15.129 to 210.167.15.142210.167.15.14314
250210.167.15.144/28210.167.15.145 to 210.167.15.158210.167.15.15914
251210.167.15.160/28210.167.15.161 to 210.167.15.174210.167.15.17514
252210.167.15.176/28210.167.15.177 to 210.167.15.190210.167.15.19114
253210.167.15.192/28210.167.15.193 to 210.167.15.206210.167.15.20714
254210.167.15.208/28210.167.15.209 to 210.167.15.222210.167.15.22314
255210.167.15.224/28210.167.15.225 to 210.167.15.238210.167.15.23914
256210.167.15.240/28210.167.15.241 to 210.167.15.254210.167.15.25514

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.