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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.

Network239.2.0.0/19
Usable hosts8,190
Subnet mask255.255.224.0
Addresses8,192
Network address
239.2.0.0
Broadcast address
239.2.31.255
First usable
239.2.0.1
Last usable
239.2.31.254
Usable hosts
8,190 (8,192 less the network and broadcast addresses)
Subnet mask
255.255.224.0
Wildcard mask
0.0.31.255 (Cisco ACLs, OSPF)
Prefix length
/19
Type
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex EF020000 · Integer 4009885696 to 4009893887
Reverse DNS zones
0.2.239.in-addr.arpa
1.2.239.in-addr.arpa
2.2.239.in-addr.arpa
3.2.239.in-addr.arpa
4.2.239.in-addr.arpa
5.2.239.in-addr.arpa
6.2.239.in-addr.arpa
7.2.239.in-addr.arpa
8.2.239.in-addr.arpa
9.2.239.in-addr.arpa
10.2.239.in-addr.arpa
11.2.239.in-addr.arpa
12.2.239.in-addr.arpa
13.2.239.in-addr.arpa
14.2.239.in-addr.arpa
15.2.239.in-addr.arpa
and 16 more
/19 is not on a 8-bit boundary, so it takes 32 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11101111.00000010.00000000.00000000239.2.0.0
Subnet mask11111111.11111111.11100000.00000000255.255.224.0
Network11101111.00000010.00000000.00000000239.2.0.0
Broadcast11101111.00000010.00011111.11111111239.2.31.255
Split into smaller subnets/27
/20 (2)/21 (4)/22 (8)/23 (16)/24 (32)/25 (64)/26 (128)/27 (256)/28 (512)/29 (1,024)/30 (2,048)/31 (4,096)

239.2.0.0/19 makes 256 subnets of /27.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1239.2.0.0/27239.2.0.1 to 239.2.0.30239.2.0.3130
2239.2.0.32/27239.2.0.33 to 239.2.0.62239.2.0.6330
3239.2.0.64/27239.2.0.65 to 239.2.0.94239.2.0.9530
4239.2.0.96/27239.2.0.97 to 239.2.0.126239.2.0.12730
5239.2.0.128/27239.2.0.129 to 239.2.0.158239.2.0.15930
6239.2.0.160/27239.2.0.161 to 239.2.0.190239.2.0.19130
7239.2.0.192/27239.2.0.193 to 239.2.0.222239.2.0.22330
8239.2.0.224/27239.2.0.225 to 239.2.0.254239.2.0.25530
9239.2.1.0/27239.2.1.1 to 239.2.1.30239.2.1.3130
10239.2.1.32/27239.2.1.33 to 239.2.1.62239.2.1.6330
11239.2.1.64/27239.2.1.65 to 239.2.1.94239.2.1.9530
12239.2.1.96/27239.2.1.97 to 239.2.1.126239.2.1.12730
13239.2.1.128/27239.2.1.129 to 239.2.1.158239.2.1.15930
14239.2.1.160/27239.2.1.161 to 239.2.1.190239.2.1.19130
15239.2.1.192/27239.2.1.193 to 239.2.1.222239.2.1.22330
16239.2.1.224/27239.2.1.225 to 239.2.1.254239.2.1.25530
17239.2.2.0/27239.2.2.1 to 239.2.2.30239.2.2.3130
18239.2.2.32/27239.2.2.33 to 239.2.2.62239.2.2.6330
19239.2.2.64/27239.2.2.65 to 239.2.2.94239.2.2.9530
20239.2.2.96/27239.2.2.97 to 239.2.2.126239.2.2.12730
21239.2.2.128/27239.2.2.129 to 239.2.2.158239.2.2.15930
22239.2.2.160/27239.2.2.161 to 239.2.2.190239.2.2.19130
23239.2.2.192/27239.2.2.193 to 239.2.2.222239.2.2.22330
24239.2.2.224/27239.2.2.225 to 239.2.2.254239.2.2.25530
25239.2.3.0/27239.2.3.1 to 239.2.3.30239.2.3.3130
26239.2.3.32/27239.2.3.33 to 239.2.3.62239.2.3.6330
27239.2.3.64/27239.2.3.65 to 239.2.3.94239.2.3.9530
28239.2.3.96/27239.2.3.97 to 239.2.3.126239.2.3.12730
29239.2.3.128/27239.2.3.129 to 239.2.3.158239.2.3.15930
30239.2.3.160/27239.2.3.161 to 239.2.3.190239.2.3.19130
31239.2.3.192/27239.2.3.193 to 239.2.3.222239.2.3.22330
32239.2.3.224/27239.2.3.225 to 239.2.3.254239.2.3.25530
33239.2.4.0/27239.2.4.1 to 239.2.4.30239.2.4.3130
34239.2.4.32/27239.2.4.33 to 239.2.4.62239.2.4.6330
35239.2.4.64/27239.2.4.65 to 239.2.4.94239.2.4.9530
36239.2.4.96/27239.2.4.97 to 239.2.4.126239.2.4.12730
37239.2.4.128/27239.2.4.129 to 239.2.4.158239.2.4.15930
38239.2.4.160/27239.2.4.161 to 239.2.4.190239.2.4.19130
39239.2.4.192/27239.2.4.193 to 239.2.4.222239.2.4.22330
40239.2.4.224/27239.2.4.225 to 239.2.4.254239.2.4.25530
41239.2.5.0/27239.2.5.1 to 239.2.5.30239.2.5.3130
42239.2.5.32/27239.2.5.33 to 239.2.5.62239.2.5.6330
43239.2.5.64/27239.2.5.65 to 239.2.5.94239.2.5.9530
44239.2.5.96/27239.2.5.97 to 239.2.5.126239.2.5.12730
45239.2.5.128/27239.2.5.129 to 239.2.5.158239.2.5.15930
46239.2.5.160/27239.2.5.161 to 239.2.5.190239.2.5.19130
47239.2.5.192/27239.2.5.193 to 239.2.5.222239.2.5.22330
48239.2.5.224/27239.2.5.225 to 239.2.5.254239.2.5.25530
49239.2.6.0/27239.2.6.1 to 239.2.6.30239.2.6.3130
50239.2.6.32/27239.2.6.33 to 239.2.6.62239.2.6.6330
51239.2.6.64/27239.2.6.65 to 239.2.6.94239.2.6.9530
52239.2.6.96/27239.2.6.97 to 239.2.6.126239.2.6.12730
53239.2.6.128/27239.2.6.129 to 239.2.6.158239.2.6.15930
54239.2.6.160/27239.2.6.161 to 239.2.6.190239.2.6.19130
55239.2.6.192/27239.2.6.193 to 239.2.6.222239.2.6.22330
56239.2.6.224/27239.2.6.225 to 239.2.6.254239.2.6.25530
57239.2.7.0/27239.2.7.1 to 239.2.7.30239.2.7.3130
58239.2.7.32/27239.2.7.33 to 239.2.7.62239.2.7.6330
59239.2.7.64/27239.2.7.65 to 239.2.7.94239.2.7.9530
60239.2.7.96/27239.2.7.97 to 239.2.7.126239.2.7.12730
61239.2.7.128/27239.2.7.129 to 239.2.7.158239.2.7.15930
62239.2.7.160/27239.2.7.161 to 239.2.7.190239.2.7.19130
63239.2.7.192/27239.2.7.193 to 239.2.7.222239.2.7.22330
64239.2.7.224/27239.2.7.225 to 239.2.7.254239.2.7.25530
65239.2.8.0/27239.2.8.1 to 239.2.8.30239.2.8.3130
66239.2.8.32/27239.2.8.33 to 239.2.8.62239.2.8.6330
67239.2.8.64/27239.2.8.65 to 239.2.8.94239.2.8.9530
68239.2.8.96/27239.2.8.97 to 239.2.8.126239.2.8.12730
69239.2.8.128/27239.2.8.129 to 239.2.8.158239.2.8.15930
70239.2.8.160/27239.2.8.161 to 239.2.8.190239.2.8.19130
71239.2.8.192/27239.2.8.193 to 239.2.8.222239.2.8.22330
72239.2.8.224/27239.2.8.225 to 239.2.8.254239.2.8.25530
73239.2.9.0/27239.2.9.1 to 239.2.9.30239.2.9.3130
74239.2.9.32/27239.2.9.33 to 239.2.9.62239.2.9.6330
75239.2.9.64/27239.2.9.65 to 239.2.9.94239.2.9.9530
76239.2.9.96/27239.2.9.97 to 239.2.9.126239.2.9.12730
77239.2.9.128/27239.2.9.129 to 239.2.9.158239.2.9.15930
78239.2.9.160/27239.2.9.161 to 239.2.9.190239.2.9.19130
79239.2.9.192/27239.2.9.193 to 239.2.9.222239.2.9.22330
80239.2.9.224/27239.2.9.225 to 239.2.9.254239.2.9.25530
81239.2.10.0/27239.2.10.1 to 239.2.10.30239.2.10.3130
82239.2.10.32/27239.2.10.33 to 239.2.10.62239.2.10.6330
83239.2.10.64/27239.2.10.65 to 239.2.10.94239.2.10.9530
84239.2.10.96/27239.2.10.97 to 239.2.10.126239.2.10.12730
85239.2.10.128/27239.2.10.129 to 239.2.10.158239.2.10.15930
86239.2.10.160/27239.2.10.161 to 239.2.10.190239.2.10.19130
87239.2.10.192/27239.2.10.193 to 239.2.10.222239.2.10.22330
88239.2.10.224/27239.2.10.225 to 239.2.10.254239.2.10.25530
89239.2.11.0/27239.2.11.1 to 239.2.11.30239.2.11.3130
90239.2.11.32/27239.2.11.33 to 239.2.11.62239.2.11.6330
91239.2.11.64/27239.2.11.65 to 239.2.11.94239.2.11.9530
92239.2.11.96/27239.2.11.97 to 239.2.11.126239.2.11.12730
93239.2.11.128/27239.2.11.129 to 239.2.11.158239.2.11.15930
94239.2.11.160/27239.2.11.161 to 239.2.11.190239.2.11.19130
95239.2.11.192/27239.2.11.193 to 239.2.11.222239.2.11.22330
96239.2.11.224/27239.2.11.225 to 239.2.11.254239.2.11.25530
97239.2.12.0/27239.2.12.1 to 239.2.12.30239.2.12.3130
98239.2.12.32/27239.2.12.33 to 239.2.12.62239.2.12.6330
99239.2.12.64/27239.2.12.65 to 239.2.12.94239.2.12.9530
100239.2.12.96/27239.2.12.97 to 239.2.12.126239.2.12.12730
101239.2.12.128/27239.2.12.129 to 239.2.12.158239.2.12.15930
102239.2.12.160/27239.2.12.161 to 239.2.12.190239.2.12.19130
103239.2.12.192/27239.2.12.193 to 239.2.12.222239.2.12.22330
104239.2.12.224/27239.2.12.225 to 239.2.12.254239.2.12.25530
105239.2.13.0/27239.2.13.1 to 239.2.13.30239.2.13.3130
106239.2.13.32/27239.2.13.33 to 239.2.13.62239.2.13.6330
107239.2.13.64/27239.2.13.65 to 239.2.13.94239.2.13.9530
108239.2.13.96/27239.2.13.97 to 239.2.13.126239.2.13.12730
109239.2.13.128/27239.2.13.129 to 239.2.13.158239.2.13.15930
110239.2.13.160/27239.2.13.161 to 239.2.13.190239.2.13.19130
111239.2.13.192/27239.2.13.193 to 239.2.13.222239.2.13.22330
112239.2.13.224/27239.2.13.225 to 239.2.13.254239.2.13.25530
113239.2.14.0/27239.2.14.1 to 239.2.14.30239.2.14.3130
114239.2.14.32/27239.2.14.33 to 239.2.14.62239.2.14.6330
115239.2.14.64/27239.2.14.65 to 239.2.14.94239.2.14.9530
116239.2.14.96/27239.2.14.97 to 239.2.14.126239.2.14.12730
117239.2.14.128/27239.2.14.129 to 239.2.14.158239.2.14.15930
118239.2.14.160/27239.2.14.161 to 239.2.14.190239.2.14.19130
119239.2.14.192/27239.2.14.193 to 239.2.14.222239.2.14.22330
120239.2.14.224/27239.2.14.225 to 239.2.14.254239.2.14.25530
121239.2.15.0/27239.2.15.1 to 239.2.15.30239.2.15.3130
122239.2.15.32/27239.2.15.33 to 239.2.15.62239.2.15.6330
123239.2.15.64/27239.2.15.65 to 239.2.15.94239.2.15.9530
124239.2.15.96/27239.2.15.97 to 239.2.15.126239.2.15.12730
125239.2.15.128/27239.2.15.129 to 239.2.15.158239.2.15.15930
126239.2.15.160/27239.2.15.161 to 239.2.15.190239.2.15.19130
127239.2.15.192/27239.2.15.193 to 239.2.15.222239.2.15.22330
128239.2.15.224/27239.2.15.225 to 239.2.15.254239.2.15.25530
129239.2.16.0/27239.2.16.1 to 239.2.16.30239.2.16.3130
130239.2.16.32/27239.2.16.33 to 239.2.16.62239.2.16.6330
131239.2.16.64/27239.2.16.65 to 239.2.16.94239.2.16.9530
132239.2.16.96/27239.2.16.97 to 239.2.16.126239.2.16.12730
133239.2.16.128/27239.2.16.129 to 239.2.16.158239.2.16.15930
134239.2.16.160/27239.2.16.161 to 239.2.16.190239.2.16.19130
135239.2.16.192/27239.2.16.193 to 239.2.16.222239.2.16.22330
136239.2.16.224/27239.2.16.225 to 239.2.16.254239.2.16.25530
137239.2.17.0/27239.2.17.1 to 239.2.17.30239.2.17.3130
138239.2.17.32/27239.2.17.33 to 239.2.17.62239.2.17.6330
139239.2.17.64/27239.2.17.65 to 239.2.17.94239.2.17.9530
140239.2.17.96/27239.2.17.97 to 239.2.17.126239.2.17.12730
141239.2.17.128/27239.2.17.129 to 239.2.17.158239.2.17.15930
142239.2.17.160/27239.2.17.161 to 239.2.17.190239.2.17.19130
143239.2.17.192/27239.2.17.193 to 239.2.17.222239.2.17.22330
144239.2.17.224/27239.2.17.225 to 239.2.17.254239.2.17.25530
145239.2.18.0/27239.2.18.1 to 239.2.18.30239.2.18.3130
146239.2.18.32/27239.2.18.33 to 239.2.18.62239.2.18.6330
147239.2.18.64/27239.2.18.65 to 239.2.18.94239.2.18.9530
148239.2.18.96/27239.2.18.97 to 239.2.18.126239.2.18.12730
149239.2.18.128/27239.2.18.129 to 239.2.18.158239.2.18.15930
150239.2.18.160/27239.2.18.161 to 239.2.18.190239.2.18.19130
151239.2.18.192/27239.2.18.193 to 239.2.18.222239.2.18.22330
152239.2.18.224/27239.2.18.225 to 239.2.18.254239.2.18.25530
153239.2.19.0/27239.2.19.1 to 239.2.19.30239.2.19.3130
154239.2.19.32/27239.2.19.33 to 239.2.19.62239.2.19.6330
155239.2.19.64/27239.2.19.65 to 239.2.19.94239.2.19.9530
156239.2.19.96/27239.2.19.97 to 239.2.19.126239.2.19.12730
157239.2.19.128/27239.2.19.129 to 239.2.19.158239.2.19.15930
158239.2.19.160/27239.2.19.161 to 239.2.19.190239.2.19.19130
159239.2.19.192/27239.2.19.193 to 239.2.19.222239.2.19.22330
160239.2.19.224/27239.2.19.225 to 239.2.19.254239.2.19.25530
161239.2.20.0/27239.2.20.1 to 239.2.20.30239.2.20.3130
162239.2.20.32/27239.2.20.33 to 239.2.20.62239.2.20.6330
163239.2.20.64/27239.2.20.65 to 239.2.20.94239.2.20.9530
164239.2.20.96/27239.2.20.97 to 239.2.20.126239.2.20.12730
165239.2.20.128/27239.2.20.129 to 239.2.20.158239.2.20.15930
166239.2.20.160/27239.2.20.161 to 239.2.20.190239.2.20.19130
167239.2.20.192/27239.2.20.193 to 239.2.20.222239.2.20.22330
168239.2.20.224/27239.2.20.225 to 239.2.20.254239.2.20.25530
169239.2.21.0/27239.2.21.1 to 239.2.21.30239.2.21.3130
170239.2.21.32/27239.2.21.33 to 239.2.21.62239.2.21.6330
171239.2.21.64/27239.2.21.65 to 239.2.21.94239.2.21.9530
172239.2.21.96/27239.2.21.97 to 239.2.21.126239.2.21.12730
173239.2.21.128/27239.2.21.129 to 239.2.21.158239.2.21.15930
174239.2.21.160/27239.2.21.161 to 239.2.21.190239.2.21.19130
175239.2.21.192/27239.2.21.193 to 239.2.21.222239.2.21.22330
176239.2.21.224/27239.2.21.225 to 239.2.21.254239.2.21.25530
177239.2.22.0/27239.2.22.1 to 239.2.22.30239.2.22.3130
178239.2.22.32/27239.2.22.33 to 239.2.22.62239.2.22.6330
179239.2.22.64/27239.2.22.65 to 239.2.22.94239.2.22.9530
180239.2.22.96/27239.2.22.97 to 239.2.22.126239.2.22.12730
181239.2.22.128/27239.2.22.129 to 239.2.22.158239.2.22.15930
182239.2.22.160/27239.2.22.161 to 239.2.22.190239.2.22.19130
183239.2.22.192/27239.2.22.193 to 239.2.22.222239.2.22.22330
184239.2.22.224/27239.2.22.225 to 239.2.22.254239.2.22.25530
185239.2.23.0/27239.2.23.1 to 239.2.23.30239.2.23.3130
186239.2.23.32/27239.2.23.33 to 239.2.23.62239.2.23.6330
187239.2.23.64/27239.2.23.65 to 239.2.23.94239.2.23.9530
188239.2.23.96/27239.2.23.97 to 239.2.23.126239.2.23.12730
189239.2.23.128/27239.2.23.129 to 239.2.23.158239.2.23.15930
190239.2.23.160/27239.2.23.161 to 239.2.23.190239.2.23.19130
191239.2.23.192/27239.2.23.193 to 239.2.23.222239.2.23.22330
192239.2.23.224/27239.2.23.225 to 239.2.23.254239.2.23.25530
193239.2.24.0/27239.2.24.1 to 239.2.24.30239.2.24.3130
194239.2.24.32/27239.2.24.33 to 239.2.24.62239.2.24.6330
195239.2.24.64/27239.2.24.65 to 239.2.24.94239.2.24.9530
196239.2.24.96/27239.2.24.97 to 239.2.24.126239.2.24.12730
197239.2.24.128/27239.2.24.129 to 239.2.24.158239.2.24.15930
198239.2.24.160/27239.2.24.161 to 239.2.24.190239.2.24.19130
199239.2.24.192/27239.2.24.193 to 239.2.24.222239.2.24.22330
200239.2.24.224/27239.2.24.225 to 239.2.24.254239.2.24.25530
201239.2.25.0/27239.2.25.1 to 239.2.25.30239.2.25.3130
202239.2.25.32/27239.2.25.33 to 239.2.25.62239.2.25.6330
203239.2.25.64/27239.2.25.65 to 239.2.25.94239.2.25.9530
204239.2.25.96/27239.2.25.97 to 239.2.25.126239.2.25.12730
205239.2.25.128/27239.2.25.129 to 239.2.25.158239.2.25.15930
206239.2.25.160/27239.2.25.161 to 239.2.25.190239.2.25.19130
207239.2.25.192/27239.2.25.193 to 239.2.25.222239.2.25.22330
208239.2.25.224/27239.2.25.225 to 239.2.25.254239.2.25.25530
209239.2.26.0/27239.2.26.1 to 239.2.26.30239.2.26.3130
210239.2.26.32/27239.2.26.33 to 239.2.26.62239.2.26.6330
211239.2.26.64/27239.2.26.65 to 239.2.26.94239.2.26.9530
212239.2.26.96/27239.2.26.97 to 239.2.26.126239.2.26.12730
213239.2.26.128/27239.2.26.129 to 239.2.26.158239.2.26.15930
214239.2.26.160/27239.2.26.161 to 239.2.26.190239.2.26.19130
215239.2.26.192/27239.2.26.193 to 239.2.26.222239.2.26.22330
216239.2.26.224/27239.2.26.225 to 239.2.26.254239.2.26.25530
217239.2.27.0/27239.2.27.1 to 239.2.27.30239.2.27.3130
218239.2.27.32/27239.2.27.33 to 239.2.27.62239.2.27.6330
219239.2.27.64/27239.2.27.65 to 239.2.27.94239.2.27.9530
220239.2.27.96/27239.2.27.97 to 239.2.27.126239.2.27.12730
221239.2.27.128/27239.2.27.129 to 239.2.27.158239.2.27.15930
222239.2.27.160/27239.2.27.161 to 239.2.27.190239.2.27.19130
223239.2.27.192/27239.2.27.193 to 239.2.27.222239.2.27.22330
224239.2.27.224/27239.2.27.225 to 239.2.27.254239.2.27.25530
225239.2.28.0/27239.2.28.1 to 239.2.28.30239.2.28.3130
226239.2.28.32/27239.2.28.33 to 239.2.28.62239.2.28.6330
227239.2.28.64/27239.2.28.65 to 239.2.28.94239.2.28.9530
228239.2.28.96/27239.2.28.97 to 239.2.28.126239.2.28.12730
229239.2.28.128/27239.2.28.129 to 239.2.28.158239.2.28.15930
230239.2.28.160/27239.2.28.161 to 239.2.28.190239.2.28.19130
231239.2.28.192/27239.2.28.193 to 239.2.28.222239.2.28.22330
232239.2.28.224/27239.2.28.225 to 239.2.28.254239.2.28.25530
233239.2.29.0/27239.2.29.1 to 239.2.29.30239.2.29.3130
234239.2.29.32/27239.2.29.33 to 239.2.29.62239.2.29.6330
235239.2.29.64/27239.2.29.65 to 239.2.29.94239.2.29.9530
236239.2.29.96/27239.2.29.97 to 239.2.29.126239.2.29.12730
237239.2.29.128/27239.2.29.129 to 239.2.29.158239.2.29.15930
238239.2.29.160/27239.2.29.161 to 239.2.29.190239.2.29.19130
239239.2.29.192/27239.2.29.193 to 239.2.29.222239.2.29.22330
240239.2.29.224/27239.2.29.225 to 239.2.29.254239.2.29.25530
241239.2.30.0/27239.2.30.1 to 239.2.30.30239.2.30.3130
242239.2.30.32/27239.2.30.33 to 239.2.30.62239.2.30.6330
243239.2.30.64/27239.2.30.65 to 239.2.30.94239.2.30.9530
244239.2.30.96/27239.2.30.97 to 239.2.30.126239.2.30.12730
245239.2.30.128/27239.2.30.129 to 239.2.30.158239.2.30.15930
246239.2.30.160/27239.2.30.161 to 239.2.30.190239.2.30.19130
247239.2.30.192/27239.2.30.193 to 239.2.30.222239.2.30.22330
248239.2.30.224/27239.2.30.225 to 239.2.30.254239.2.30.25530
249239.2.31.0/27239.2.31.1 to 239.2.31.30239.2.31.3130
250239.2.31.32/27239.2.31.33 to 239.2.31.62239.2.31.6330
251239.2.31.64/27239.2.31.65 to 239.2.31.94239.2.31.9530
252239.2.31.96/27239.2.31.97 to 239.2.31.126239.2.31.12730
253239.2.31.128/27239.2.31.129 to 239.2.31.158239.2.31.15930
254239.2.31.160/27239.2.31.161 to 239.2.31.190239.2.31.19130
255239.2.31.192/27239.2.31.193 to 239.2.31.222239.2.31.22330
256239.2.31.224/27239.2.31.225 to 239.2.31.254239.2.31.25530

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.