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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.

Network120.167.64.0/18
Usable hosts16,382
Subnet mask255.255.192.0
Addresses16,384
Network address
120.167.64.0
Broadcast address
120.167.127.255
First usable
120.167.64.1
Last usable
120.167.127.254
Usable hosts
16,382 (16,384 less the network and broadcast addresses)
Subnet mask
255.255.192.0
Wildcard mask
0.0.63.255 (Cisco ACLs, OSPF)
Prefix length
/18
Type
Public public
Old class
A (default /8)
As numbers
Hex 78A74000 · Integer 2024226816 to 2024243199
Reverse DNS zones
64.167.120.in-addr.arpa
65.167.120.in-addr.arpa
66.167.120.in-addr.arpa
67.167.120.in-addr.arpa
68.167.120.in-addr.arpa
69.167.120.in-addr.arpa
70.167.120.in-addr.arpa
71.167.120.in-addr.arpa
72.167.120.in-addr.arpa
73.167.120.in-addr.arpa
74.167.120.in-addr.arpa
75.167.120.in-addr.arpa
76.167.120.in-addr.arpa
77.167.120.in-addr.arpa
78.167.120.in-addr.arpa
79.167.120.in-addr.arpa
and 48 more
/18 is not on a 8-bit boundary, so it takes 64 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01111000.10100111.01000000.00000000120.167.64.0
Subnet mask11111111.11111111.11000000.00000000255.255.192.0
Network01111000.10100111.01000000.00000000120.167.64.0
Broadcast01111000.10100111.01111111.11111111120.167.127.255
Split into smaller subnets/27
/19 (2)/20 (4)/21 (8)/22 (16)/23 (32)/24 (64)/25 (128)/26 (256)/27 (512)/28 (1,024)/29 (2,048)/30 (4,096)

120.167.64.0/18 makes 512 subnets of /27; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1120.167.64.0/27120.167.64.1 to 120.167.64.30120.167.64.3130
2120.167.64.32/27120.167.64.33 to 120.167.64.62120.167.64.6330
3120.167.64.64/27120.167.64.65 to 120.167.64.94120.167.64.9530
4120.167.64.96/27120.167.64.97 to 120.167.64.126120.167.64.12730
5120.167.64.128/27120.167.64.129 to 120.167.64.158120.167.64.15930
6120.167.64.160/27120.167.64.161 to 120.167.64.190120.167.64.19130
7120.167.64.192/27120.167.64.193 to 120.167.64.222120.167.64.22330
8120.167.64.224/27120.167.64.225 to 120.167.64.254120.167.64.25530
9120.167.65.0/27120.167.65.1 to 120.167.65.30120.167.65.3130
10120.167.65.32/27120.167.65.33 to 120.167.65.62120.167.65.6330
11120.167.65.64/27120.167.65.65 to 120.167.65.94120.167.65.9530
12120.167.65.96/27120.167.65.97 to 120.167.65.126120.167.65.12730
13120.167.65.128/27120.167.65.129 to 120.167.65.158120.167.65.15930
14120.167.65.160/27120.167.65.161 to 120.167.65.190120.167.65.19130
15120.167.65.192/27120.167.65.193 to 120.167.65.222120.167.65.22330
16120.167.65.224/27120.167.65.225 to 120.167.65.254120.167.65.25530
17120.167.66.0/27120.167.66.1 to 120.167.66.30120.167.66.3130
18120.167.66.32/27120.167.66.33 to 120.167.66.62120.167.66.6330
19120.167.66.64/27120.167.66.65 to 120.167.66.94120.167.66.9530
20120.167.66.96/27120.167.66.97 to 120.167.66.126120.167.66.12730
21120.167.66.128/27120.167.66.129 to 120.167.66.158120.167.66.15930
22120.167.66.160/27120.167.66.161 to 120.167.66.190120.167.66.19130
23120.167.66.192/27120.167.66.193 to 120.167.66.222120.167.66.22330
24120.167.66.224/27120.167.66.225 to 120.167.66.254120.167.66.25530
25120.167.67.0/27120.167.67.1 to 120.167.67.30120.167.67.3130
26120.167.67.32/27120.167.67.33 to 120.167.67.62120.167.67.6330
27120.167.67.64/27120.167.67.65 to 120.167.67.94120.167.67.9530
28120.167.67.96/27120.167.67.97 to 120.167.67.126120.167.67.12730
29120.167.67.128/27120.167.67.129 to 120.167.67.158120.167.67.15930
30120.167.67.160/27120.167.67.161 to 120.167.67.190120.167.67.19130
31120.167.67.192/27120.167.67.193 to 120.167.67.222120.167.67.22330
32120.167.67.224/27120.167.67.225 to 120.167.67.254120.167.67.25530
33120.167.68.0/27120.167.68.1 to 120.167.68.30120.167.68.3130
34120.167.68.32/27120.167.68.33 to 120.167.68.62120.167.68.6330
35120.167.68.64/27120.167.68.65 to 120.167.68.94120.167.68.9530
36120.167.68.96/27120.167.68.97 to 120.167.68.126120.167.68.12730
37120.167.68.128/27120.167.68.129 to 120.167.68.158120.167.68.15930
38120.167.68.160/27120.167.68.161 to 120.167.68.190120.167.68.19130
39120.167.68.192/27120.167.68.193 to 120.167.68.222120.167.68.22330
40120.167.68.224/27120.167.68.225 to 120.167.68.254120.167.68.25530
41120.167.69.0/27120.167.69.1 to 120.167.69.30120.167.69.3130
42120.167.69.32/27120.167.69.33 to 120.167.69.62120.167.69.6330
43120.167.69.64/27120.167.69.65 to 120.167.69.94120.167.69.9530
44120.167.69.96/27120.167.69.97 to 120.167.69.126120.167.69.12730
45120.167.69.128/27120.167.69.129 to 120.167.69.158120.167.69.15930
46120.167.69.160/27120.167.69.161 to 120.167.69.190120.167.69.19130
47120.167.69.192/27120.167.69.193 to 120.167.69.222120.167.69.22330
48120.167.69.224/27120.167.69.225 to 120.167.69.254120.167.69.25530
49120.167.70.0/27120.167.70.1 to 120.167.70.30120.167.70.3130
50120.167.70.32/27120.167.70.33 to 120.167.70.62120.167.70.6330
51120.167.70.64/27120.167.70.65 to 120.167.70.94120.167.70.9530
52120.167.70.96/27120.167.70.97 to 120.167.70.126120.167.70.12730
53120.167.70.128/27120.167.70.129 to 120.167.70.158120.167.70.15930
54120.167.70.160/27120.167.70.161 to 120.167.70.190120.167.70.19130
55120.167.70.192/27120.167.70.193 to 120.167.70.222120.167.70.22330
56120.167.70.224/27120.167.70.225 to 120.167.70.254120.167.70.25530
57120.167.71.0/27120.167.71.1 to 120.167.71.30120.167.71.3130
58120.167.71.32/27120.167.71.33 to 120.167.71.62120.167.71.6330
59120.167.71.64/27120.167.71.65 to 120.167.71.94120.167.71.9530
60120.167.71.96/27120.167.71.97 to 120.167.71.126120.167.71.12730
61120.167.71.128/27120.167.71.129 to 120.167.71.158120.167.71.15930
62120.167.71.160/27120.167.71.161 to 120.167.71.190120.167.71.19130
63120.167.71.192/27120.167.71.193 to 120.167.71.222120.167.71.22330
64120.167.71.224/27120.167.71.225 to 120.167.71.254120.167.71.25530
65120.167.72.0/27120.167.72.1 to 120.167.72.30120.167.72.3130
66120.167.72.32/27120.167.72.33 to 120.167.72.62120.167.72.6330
67120.167.72.64/27120.167.72.65 to 120.167.72.94120.167.72.9530
68120.167.72.96/27120.167.72.97 to 120.167.72.126120.167.72.12730
69120.167.72.128/27120.167.72.129 to 120.167.72.158120.167.72.15930
70120.167.72.160/27120.167.72.161 to 120.167.72.190120.167.72.19130
71120.167.72.192/27120.167.72.193 to 120.167.72.222120.167.72.22330
72120.167.72.224/27120.167.72.225 to 120.167.72.254120.167.72.25530
73120.167.73.0/27120.167.73.1 to 120.167.73.30120.167.73.3130
74120.167.73.32/27120.167.73.33 to 120.167.73.62120.167.73.6330
75120.167.73.64/27120.167.73.65 to 120.167.73.94120.167.73.9530
76120.167.73.96/27120.167.73.97 to 120.167.73.126120.167.73.12730
77120.167.73.128/27120.167.73.129 to 120.167.73.158120.167.73.15930
78120.167.73.160/27120.167.73.161 to 120.167.73.190120.167.73.19130
79120.167.73.192/27120.167.73.193 to 120.167.73.222120.167.73.22330
80120.167.73.224/27120.167.73.225 to 120.167.73.254120.167.73.25530
81120.167.74.0/27120.167.74.1 to 120.167.74.30120.167.74.3130
82120.167.74.32/27120.167.74.33 to 120.167.74.62120.167.74.6330
83120.167.74.64/27120.167.74.65 to 120.167.74.94120.167.74.9530
84120.167.74.96/27120.167.74.97 to 120.167.74.126120.167.74.12730
85120.167.74.128/27120.167.74.129 to 120.167.74.158120.167.74.15930
86120.167.74.160/27120.167.74.161 to 120.167.74.190120.167.74.19130
87120.167.74.192/27120.167.74.193 to 120.167.74.222120.167.74.22330
88120.167.74.224/27120.167.74.225 to 120.167.74.254120.167.74.25530
89120.167.75.0/27120.167.75.1 to 120.167.75.30120.167.75.3130
90120.167.75.32/27120.167.75.33 to 120.167.75.62120.167.75.6330
91120.167.75.64/27120.167.75.65 to 120.167.75.94120.167.75.9530
92120.167.75.96/27120.167.75.97 to 120.167.75.126120.167.75.12730
93120.167.75.128/27120.167.75.129 to 120.167.75.158120.167.75.15930
94120.167.75.160/27120.167.75.161 to 120.167.75.190120.167.75.19130
95120.167.75.192/27120.167.75.193 to 120.167.75.222120.167.75.22330
96120.167.75.224/27120.167.75.225 to 120.167.75.254120.167.75.25530
97120.167.76.0/27120.167.76.1 to 120.167.76.30120.167.76.3130
98120.167.76.32/27120.167.76.33 to 120.167.76.62120.167.76.6330
99120.167.76.64/27120.167.76.65 to 120.167.76.94120.167.76.9530
100120.167.76.96/27120.167.76.97 to 120.167.76.126120.167.76.12730
101120.167.76.128/27120.167.76.129 to 120.167.76.158120.167.76.15930
102120.167.76.160/27120.167.76.161 to 120.167.76.190120.167.76.19130
103120.167.76.192/27120.167.76.193 to 120.167.76.222120.167.76.22330
104120.167.76.224/27120.167.76.225 to 120.167.76.254120.167.76.25530
105120.167.77.0/27120.167.77.1 to 120.167.77.30120.167.77.3130
106120.167.77.32/27120.167.77.33 to 120.167.77.62120.167.77.6330
107120.167.77.64/27120.167.77.65 to 120.167.77.94120.167.77.9530
108120.167.77.96/27120.167.77.97 to 120.167.77.126120.167.77.12730
109120.167.77.128/27120.167.77.129 to 120.167.77.158120.167.77.15930
110120.167.77.160/27120.167.77.161 to 120.167.77.190120.167.77.19130
111120.167.77.192/27120.167.77.193 to 120.167.77.222120.167.77.22330
112120.167.77.224/27120.167.77.225 to 120.167.77.254120.167.77.25530
113120.167.78.0/27120.167.78.1 to 120.167.78.30120.167.78.3130
114120.167.78.32/27120.167.78.33 to 120.167.78.62120.167.78.6330
115120.167.78.64/27120.167.78.65 to 120.167.78.94120.167.78.9530
116120.167.78.96/27120.167.78.97 to 120.167.78.126120.167.78.12730
117120.167.78.128/27120.167.78.129 to 120.167.78.158120.167.78.15930
118120.167.78.160/27120.167.78.161 to 120.167.78.190120.167.78.19130
119120.167.78.192/27120.167.78.193 to 120.167.78.222120.167.78.22330
120120.167.78.224/27120.167.78.225 to 120.167.78.254120.167.78.25530
121120.167.79.0/27120.167.79.1 to 120.167.79.30120.167.79.3130
122120.167.79.32/27120.167.79.33 to 120.167.79.62120.167.79.6330
123120.167.79.64/27120.167.79.65 to 120.167.79.94120.167.79.9530
124120.167.79.96/27120.167.79.97 to 120.167.79.126120.167.79.12730
125120.167.79.128/27120.167.79.129 to 120.167.79.158120.167.79.15930
126120.167.79.160/27120.167.79.161 to 120.167.79.190120.167.79.19130
127120.167.79.192/27120.167.79.193 to 120.167.79.222120.167.79.22330
128120.167.79.224/27120.167.79.225 to 120.167.79.254120.167.79.25530
129120.167.80.0/27120.167.80.1 to 120.167.80.30120.167.80.3130
130120.167.80.32/27120.167.80.33 to 120.167.80.62120.167.80.6330
131120.167.80.64/27120.167.80.65 to 120.167.80.94120.167.80.9530
132120.167.80.96/27120.167.80.97 to 120.167.80.126120.167.80.12730
133120.167.80.128/27120.167.80.129 to 120.167.80.158120.167.80.15930
134120.167.80.160/27120.167.80.161 to 120.167.80.190120.167.80.19130
135120.167.80.192/27120.167.80.193 to 120.167.80.222120.167.80.22330
136120.167.80.224/27120.167.80.225 to 120.167.80.254120.167.80.25530
137120.167.81.0/27120.167.81.1 to 120.167.81.30120.167.81.3130
138120.167.81.32/27120.167.81.33 to 120.167.81.62120.167.81.6330
139120.167.81.64/27120.167.81.65 to 120.167.81.94120.167.81.9530
140120.167.81.96/27120.167.81.97 to 120.167.81.126120.167.81.12730
141120.167.81.128/27120.167.81.129 to 120.167.81.158120.167.81.15930
142120.167.81.160/27120.167.81.161 to 120.167.81.190120.167.81.19130
143120.167.81.192/27120.167.81.193 to 120.167.81.222120.167.81.22330
144120.167.81.224/27120.167.81.225 to 120.167.81.254120.167.81.25530
145120.167.82.0/27120.167.82.1 to 120.167.82.30120.167.82.3130
146120.167.82.32/27120.167.82.33 to 120.167.82.62120.167.82.6330
147120.167.82.64/27120.167.82.65 to 120.167.82.94120.167.82.9530
148120.167.82.96/27120.167.82.97 to 120.167.82.126120.167.82.12730
149120.167.82.128/27120.167.82.129 to 120.167.82.158120.167.82.15930
150120.167.82.160/27120.167.82.161 to 120.167.82.190120.167.82.19130
151120.167.82.192/27120.167.82.193 to 120.167.82.222120.167.82.22330
152120.167.82.224/27120.167.82.225 to 120.167.82.254120.167.82.25530
153120.167.83.0/27120.167.83.1 to 120.167.83.30120.167.83.3130
154120.167.83.32/27120.167.83.33 to 120.167.83.62120.167.83.6330
155120.167.83.64/27120.167.83.65 to 120.167.83.94120.167.83.9530
156120.167.83.96/27120.167.83.97 to 120.167.83.126120.167.83.12730
157120.167.83.128/27120.167.83.129 to 120.167.83.158120.167.83.15930
158120.167.83.160/27120.167.83.161 to 120.167.83.190120.167.83.19130
159120.167.83.192/27120.167.83.193 to 120.167.83.222120.167.83.22330
160120.167.83.224/27120.167.83.225 to 120.167.83.254120.167.83.25530
161120.167.84.0/27120.167.84.1 to 120.167.84.30120.167.84.3130
162120.167.84.32/27120.167.84.33 to 120.167.84.62120.167.84.6330
163120.167.84.64/27120.167.84.65 to 120.167.84.94120.167.84.9530
164120.167.84.96/27120.167.84.97 to 120.167.84.126120.167.84.12730
165120.167.84.128/27120.167.84.129 to 120.167.84.158120.167.84.15930
166120.167.84.160/27120.167.84.161 to 120.167.84.190120.167.84.19130
167120.167.84.192/27120.167.84.193 to 120.167.84.222120.167.84.22330
168120.167.84.224/27120.167.84.225 to 120.167.84.254120.167.84.25530
169120.167.85.0/27120.167.85.1 to 120.167.85.30120.167.85.3130
170120.167.85.32/27120.167.85.33 to 120.167.85.62120.167.85.6330
171120.167.85.64/27120.167.85.65 to 120.167.85.94120.167.85.9530
172120.167.85.96/27120.167.85.97 to 120.167.85.126120.167.85.12730
173120.167.85.128/27120.167.85.129 to 120.167.85.158120.167.85.15930
174120.167.85.160/27120.167.85.161 to 120.167.85.190120.167.85.19130
175120.167.85.192/27120.167.85.193 to 120.167.85.222120.167.85.22330
176120.167.85.224/27120.167.85.225 to 120.167.85.254120.167.85.25530
177120.167.86.0/27120.167.86.1 to 120.167.86.30120.167.86.3130
178120.167.86.32/27120.167.86.33 to 120.167.86.62120.167.86.6330
179120.167.86.64/27120.167.86.65 to 120.167.86.94120.167.86.9530
180120.167.86.96/27120.167.86.97 to 120.167.86.126120.167.86.12730
181120.167.86.128/27120.167.86.129 to 120.167.86.158120.167.86.15930
182120.167.86.160/27120.167.86.161 to 120.167.86.190120.167.86.19130
183120.167.86.192/27120.167.86.193 to 120.167.86.222120.167.86.22330
184120.167.86.224/27120.167.86.225 to 120.167.86.254120.167.86.25530
185120.167.87.0/27120.167.87.1 to 120.167.87.30120.167.87.3130
186120.167.87.32/27120.167.87.33 to 120.167.87.62120.167.87.6330
187120.167.87.64/27120.167.87.65 to 120.167.87.94120.167.87.9530
188120.167.87.96/27120.167.87.97 to 120.167.87.126120.167.87.12730
189120.167.87.128/27120.167.87.129 to 120.167.87.158120.167.87.15930
190120.167.87.160/27120.167.87.161 to 120.167.87.190120.167.87.19130
191120.167.87.192/27120.167.87.193 to 120.167.87.222120.167.87.22330
192120.167.87.224/27120.167.87.225 to 120.167.87.254120.167.87.25530
193120.167.88.0/27120.167.88.1 to 120.167.88.30120.167.88.3130
194120.167.88.32/27120.167.88.33 to 120.167.88.62120.167.88.6330
195120.167.88.64/27120.167.88.65 to 120.167.88.94120.167.88.9530
196120.167.88.96/27120.167.88.97 to 120.167.88.126120.167.88.12730
197120.167.88.128/27120.167.88.129 to 120.167.88.158120.167.88.15930
198120.167.88.160/27120.167.88.161 to 120.167.88.190120.167.88.19130
199120.167.88.192/27120.167.88.193 to 120.167.88.222120.167.88.22330
200120.167.88.224/27120.167.88.225 to 120.167.88.254120.167.88.25530
201120.167.89.0/27120.167.89.1 to 120.167.89.30120.167.89.3130
202120.167.89.32/27120.167.89.33 to 120.167.89.62120.167.89.6330
203120.167.89.64/27120.167.89.65 to 120.167.89.94120.167.89.9530
204120.167.89.96/27120.167.89.97 to 120.167.89.126120.167.89.12730
205120.167.89.128/27120.167.89.129 to 120.167.89.158120.167.89.15930
206120.167.89.160/27120.167.89.161 to 120.167.89.190120.167.89.19130
207120.167.89.192/27120.167.89.193 to 120.167.89.222120.167.89.22330
208120.167.89.224/27120.167.89.225 to 120.167.89.254120.167.89.25530
209120.167.90.0/27120.167.90.1 to 120.167.90.30120.167.90.3130
210120.167.90.32/27120.167.90.33 to 120.167.90.62120.167.90.6330
211120.167.90.64/27120.167.90.65 to 120.167.90.94120.167.90.9530
212120.167.90.96/27120.167.90.97 to 120.167.90.126120.167.90.12730
213120.167.90.128/27120.167.90.129 to 120.167.90.158120.167.90.15930
214120.167.90.160/27120.167.90.161 to 120.167.90.190120.167.90.19130
215120.167.90.192/27120.167.90.193 to 120.167.90.222120.167.90.22330
216120.167.90.224/27120.167.90.225 to 120.167.90.254120.167.90.25530
217120.167.91.0/27120.167.91.1 to 120.167.91.30120.167.91.3130
218120.167.91.32/27120.167.91.33 to 120.167.91.62120.167.91.6330
219120.167.91.64/27120.167.91.65 to 120.167.91.94120.167.91.9530
220120.167.91.96/27120.167.91.97 to 120.167.91.126120.167.91.12730
221120.167.91.128/27120.167.91.129 to 120.167.91.158120.167.91.15930
222120.167.91.160/27120.167.91.161 to 120.167.91.190120.167.91.19130
223120.167.91.192/27120.167.91.193 to 120.167.91.222120.167.91.22330
224120.167.91.224/27120.167.91.225 to 120.167.91.254120.167.91.25530
225120.167.92.0/27120.167.92.1 to 120.167.92.30120.167.92.3130
226120.167.92.32/27120.167.92.33 to 120.167.92.62120.167.92.6330
227120.167.92.64/27120.167.92.65 to 120.167.92.94120.167.92.9530
228120.167.92.96/27120.167.92.97 to 120.167.92.126120.167.92.12730
229120.167.92.128/27120.167.92.129 to 120.167.92.158120.167.92.15930
230120.167.92.160/27120.167.92.161 to 120.167.92.190120.167.92.19130
231120.167.92.192/27120.167.92.193 to 120.167.92.222120.167.92.22330
232120.167.92.224/27120.167.92.225 to 120.167.92.254120.167.92.25530
233120.167.93.0/27120.167.93.1 to 120.167.93.30120.167.93.3130
234120.167.93.32/27120.167.93.33 to 120.167.93.62120.167.93.6330
235120.167.93.64/27120.167.93.65 to 120.167.93.94120.167.93.9530
236120.167.93.96/27120.167.93.97 to 120.167.93.126120.167.93.12730
237120.167.93.128/27120.167.93.129 to 120.167.93.158120.167.93.15930
238120.167.93.160/27120.167.93.161 to 120.167.93.190120.167.93.19130
239120.167.93.192/27120.167.93.193 to 120.167.93.222120.167.93.22330
240120.167.93.224/27120.167.93.225 to 120.167.93.254120.167.93.25530
241120.167.94.0/27120.167.94.1 to 120.167.94.30120.167.94.3130
242120.167.94.32/27120.167.94.33 to 120.167.94.62120.167.94.6330
243120.167.94.64/27120.167.94.65 to 120.167.94.94120.167.94.9530
244120.167.94.96/27120.167.94.97 to 120.167.94.126120.167.94.12730
245120.167.94.128/27120.167.94.129 to 120.167.94.158120.167.94.15930
246120.167.94.160/27120.167.94.161 to 120.167.94.190120.167.94.19130
247120.167.94.192/27120.167.94.193 to 120.167.94.222120.167.94.22330
248120.167.94.224/27120.167.94.225 to 120.167.94.254120.167.94.25530
249120.167.95.0/27120.167.95.1 to 120.167.95.30120.167.95.3130
250120.167.95.32/27120.167.95.33 to 120.167.95.62120.167.95.6330
251120.167.95.64/27120.167.95.65 to 120.167.95.94120.167.95.9530
252120.167.95.96/27120.167.95.97 to 120.167.95.126120.167.95.12730
253120.167.95.128/27120.167.95.129 to 120.167.95.158120.167.95.15930
254120.167.95.160/27120.167.95.161 to 120.167.95.190120.167.95.19130
255120.167.95.192/27120.167.95.193 to 120.167.95.222120.167.95.22330
256120.167.95.224/27120.167.95.225 to 120.167.95.254120.167.95.25530

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.