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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.

Network116.239.0.0/17
Usable hosts32,766
Subnet mask255.255.128.0
Addresses32,768
Network address
116.239.0.0
Broadcast address
116.239.127.255
First usable
116.239.0.1
Last usable
116.239.127.254
Usable hosts
32,766 (32,768 less the network and broadcast addresses)
Subnet mask
255.255.128.0
Wildcard mask
0.0.127.255 (Cisco ACLs, OSPF)
Prefix length
/17
Type
Public public
Old class
A (default /8)
As numbers
Hex 74EF0000 · Integer 1961820160 to 1961852927
Reverse DNS zones
0.239.116.in-addr.arpa
1.239.116.in-addr.arpa
2.239.116.in-addr.arpa
3.239.116.in-addr.arpa
4.239.116.in-addr.arpa
5.239.116.in-addr.arpa
6.239.116.in-addr.arpa
7.239.116.in-addr.arpa
8.239.116.in-addr.arpa
9.239.116.in-addr.arpa
10.239.116.in-addr.arpa
11.239.116.in-addr.arpa
12.239.116.in-addr.arpa
13.239.116.in-addr.arpa
14.239.116.in-addr.arpa
15.239.116.in-addr.arpa
and 112 more
/17 is not on a 8-bit boundary, so it takes 128 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01110100.11101111.00000000.00000000116.239.0.0
Subnet mask11111111.11111111.10000000.00000000255.255.128.0
Network01110100.11101111.00000000.00000000116.239.0.0
Broadcast01110100.11101111.01111111.11111111116.239.127.255
Split into smaller subnets/27
/18 (2)/19 (4)/20 (8)/21 (16)/22 (32)/23 (64)/24 (128)/25 (256)/26 (512)/27 (1,024)/28 (2,048)/29 (4,096)

116.239.0.0/17 makes 1,024 subnets of /27; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1116.239.0.0/27116.239.0.1 to 116.239.0.30116.239.0.3130
2116.239.0.32/27116.239.0.33 to 116.239.0.62116.239.0.6330
3116.239.0.64/27116.239.0.65 to 116.239.0.94116.239.0.9530
4116.239.0.96/27116.239.0.97 to 116.239.0.126116.239.0.12730
5116.239.0.128/27116.239.0.129 to 116.239.0.158116.239.0.15930
6116.239.0.160/27116.239.0.161 to 116.239.0.190116.239.0.19130
7116.239.0.192/27116.239.0.193 to 116.239.0.222116.239.0.22330
8116.239.0.224/27116.239.0.225 to 116.239.0.254116.239.0.25530
9116.239.1.0/27116.239.1.1 to 116.239.1.30116.239.1.3130
10116.239.1.32/27116.239.1.33 to 116.239.1.62116.239.1.6330
11116.239.1.64/27116.239.1.65 to 116.239.1.94116.239.1.9530
12116.239.1.96/27116.239.1.97 to 116.239.1.126116.239.1.12730
13116.239.1.128/27116.239.1.129 to 116.239.1.158116.239.1.15930
14116.239.1.160/27116.239.1.161 to 116.239.1.190116.239.1.19130
15116.239.1.192/27116.239.1.193 to 116.239.1.222116.239.1.22330
16116.239.1.224/27116.239.1.225 to 116.239.1.254116.239.1.25530
17116.239.2.0/27116.239.2.1 to 116.239.2.30116.239.2.3130
18116.239.2.32/27116.239.2.33 to 116.239.2.62116.239.2.6330
19116.239.2.64/27116.239.2.65 to 116.239.2.94116.239.2.9530
20116.239.2.96/27116.239.2.97 to 116.239.2.126116.239.2.12730
21116.239.2.128/27116.239.2.129 to 116.239.2.158116.239.2.15930
22116.239.2.160/27116.239.2.161 to 116.239.2.190116.239.2.19130
23116.239.2.192/27116.239.2.193 to 116.239.2.222116.239.2.22330
24116.239.2.224/27116.239.2.225 to 116.239.2.254116.239.2.25530
25116.239.3.0/27116.239.3.1 to 116.239.3.30116.239.3.3130
26116.239.3.32/27116.239.3.33 to 116.239.3.62116.239.3.6330
27116.239.3.64/27116.239.3.65 to 116.239.3.94116.239.3.9530
28116.239.3.96/27116.239.3.97 to 116.239.3.126116.239.3.12730
29116.239.3.128/27116.239.3.129 to 116.239.3.158116.239.3.15930
30116.239.3.160/27116.239.3.161 to 116.239.3.190116.239.3.19130
31116.239.3.192/27116.239.3.193 to 116.239.3.222116.239.3.22330
32116.239.3.224/27116.239.3.225 to 116.239.3.254116.239.3.25530
33116.239.4.0/27116.239.4.1 to 116.239.4.30116.239.4.3130
34116.239.4.32/27116.239.4.33 to 116.239.4.62116.239.4.6330
35116.239.4.64/27116.239.4.65 to 116.239.4.94116.239.4.9530
36116.239.4.96/27116.239.4.97 to 116.239.4.126116.239.4.12730
37116.239.4.128/27116.239.4.129 to 116.239.4.158116.239.4.15930
38116.239.4.160/27116.239.4.161 to 116.239.4.190116.239.4.19130
39116.239.4.192/27116.239.4.193 to 116.239.4.222116.239.4.22330
40116.239.4.224/27116.239.4.225 to 116.239.4.254116.239.4.25530
41116.239.5.0/27116.239.5.1 to 116.239.5.30116.239.5.3130
42116.239.5.32/27116.239.5.33 to 116.239.5.62116.239.5.6330
43116.239.5.64/27116.239.5.65 to 116.239.5.94116.239.5.9530
44116.239.5.96/27116.239.5.97 to 116.239.5.126116.239.5.12730
45116.239.5.128/27116.239.5.129 to 116.239.5.158116.239.5.15930
46116.239.5.160/27116.239.5.161 to 116.239.5.190116.239.5.19130
47116.239.5.192/27116.239.5.193 to 116.239.5.222116.239.5.22330
48116.239.5.224/27116.239.5.225 to 116.239.5.254116.239.5.25530
49116.239.6.0/27116.239.6.1 to 116.239.6.30116.239.6.3130
50116.239.6.32/27116.239.6.33 to 116.239.6.62116.239.6.6330
51116.239.6.64/27116.239.6.65 to 116.239.6.94116.239.6.9530
52116.239.6.96/27116.239.6.97 to 116.239.6.126116.239.6.12730
53116.239.6.128/27116.239.6.129 to 116.239.6.158116.239.6.15930
54116.239.6.160/27116.239.6.161 to 116.239.6.190116.239.6.19130
55116.239.6.192/27116.239.6.193 to 116.239.6.222116.239.6.22330
56116.239.6.224/27116.239.6.225 to 116.239.6.254116.239.6.25530
57116.239.7.0/27116.239.7.1 to 116.239.7.30116.239.7.3130
58116.239.7.32/27116.239.7.33 to 116.239.7.62116.239.7.6330
59116.239.7.64/27116.239.7.65 to 116.239.7.94116.239.7.9530
60116.239.7.96/27116.239.7.97 to 116.239.7.126116.239.7.12730
61116.239.7.128/27116.239.7.129 to 116.239.7.158116.239.7.15930
62116.239.7.160/27116.239.7.161 to 116.239.7.190116.239.7.19130
63116.239.7.192/27116.239.7.193 to 116.239.7.222116.239.7.22330
64116.239.7.224/27116.239.7.225 to 116.239.7.254116.239.7.25530
65116.239.8.0/27116.239.8.1 to 116.239.8.30116.239.8.3130
66116.239.8.32/27116.239.8.33 to 116.239.8.62116.239.8.6330
67116.239.8.64/27116.239.8.65 to 116.239.8.94116.239.8.9530
68116.239.8.96/27116.239.8.97 to 116.239.8.126116.239.8.12730
69116.239.8.128/27116.239.8.129 to 116.239.8.158116.239.8.15930
70116.239.8.160/27116.239.8.161 to 116.239.8.190116.239.8.19130
71116.239.8.192/27116.239.8.193 to 116.239.8.222116.239.8.22330
72116.239.8.224/27116.239.8.225 to 116.239.8.254116.239.8.25530
73116.239.9.0/27116.239.9.1 to 116.239.9.30116.239.9.3130
74116.239.9.32/27116.239.9.33 to 116.239.9.62116.239.9.6330
75116.239.9.64/27116.239.9.65 to 116.239.9.94116.239.9.9530
76116.239.9.96/27116.239.9.97 to 116.239.9.126116.239.9.12730
77116.239.9.128/27116.239.9.129 to 116.239.9.158116.239.9.15930
78116.239.9.160/27116.239.9.161 to 116.239.9.190116.239.9.19130
79116.239.9.192/27116.239.9.193 to 116.239.9.222116.239.9.22330
80116.239.9.224/27116.239.9.225 to 116.239.9.254116.239.9.25530
81116.239.10.0/27116.239.10.1 to 116.239.10.30116.239.10.3130
82116.239.10.32/27116.239.10.33 to 116.239.10.62116.239.10.6330
83116.239.10.64/27116.239.10.65 to 116.239.10.94116.239.10.9530
84116.239.10.96/27116.239.10.97 to 116.239.10.126116.239.10.12730
85116.239.10.128/27116.239.10.129 to 116.239.10.158116.239.10.15930
86116.239.10.160/27116.239.10.161 to 116.239.10.190116.239.10.19130
87116.239.10.192/27116.239.10.193 to 116.239.10.222116.239.10.22330
88116.239.10.224/27116.239.10.225 to 116.239.10.254116.239.10.25530
89116.239.11.0/27116.239.11.1 to 116.239.11.30116.239.11.3130
90116.239.11.32/27116.239.11.33 to 116.239.11.62116.239.11.6330
91116.239.11.64/27116.239.11.65 to 116.239.11.94116.239.11.9530
92116.239.11.96/27116.239.11.97 to 116.239.11.126116.239.11.12730
93116.239.11.128/27116.239.11.129 to 116.239.11.158116.239.11.15930
94116.239.11.160/27116.239.11.161 to 116.239.11.190116.239.11.19130
95116.239.11.192/27116.239.11.193 to 116.239.11.222116.239.11.22330
96116.239.11.224/27116.239.11.225 to 116.239.11.254116.239.11.25530
97116.239.12.0/27116.239.12.1 to 116.239.12.30116.239.12.3130
98116.239.12.32/27116.239.12.33 to 116.239.12.62116.239.12.6330
99116.239.12.64/27116.239.12.65 to 116.239.12.94116.239.12.9530
100116.239.12.96/27116.239.12.97 to 116.239.12.126116.239.12.12730
101116.239.12.128/27116.239.12.129 to 116.239.12.158116.239.12.15930
102116.239.12.160/27116.239.12.161 to 116.239.12.190116.239.12.19130
103116.239.12.192/27116.239.12.193 to 116.239.12.222116.239.12.22330
104116.239.12.224/27116.239.12.225 to 116.239.12.254116.239.12.25530
105116.239.13.0/27116.239.13.1 to 116.239.13.30116.239.13.3130
106116.239.13.32/27116.239.13.33 to 116.239.13.62116.239.13.6330
107116.239.13.64/27116.239.13.65 to 116.239.13.94116.239.13.9530
108116.239.13.96/27116.239.13.97 to 116.239.13.126116.239.13.12730
109116.239.13.128/27116.239.13.129 to 116.239.13.158116.239.13.15930
110116.239.13.160/27116.239.13.161 to 116.239.13.190116.239.13.19130
111116.239.13.192/27116.239.13.193 to 116.239.13.222116.239.13.22330
112116.239.13.224/27116.239.13.225 to 116.239.13.254116.239.13.25530
113116.239.14.0/27116.239.14.1 to 116.239.14.30116.239.14.3130
114116.239.14.32/27116.239.14.33 to 116.239.14.62116.239.14.6330
115116.239.14.64/27116.239.14.65 to 116.239.14.94116.239.14.9530
116116.239.14.96/27116.239.14.97 to 116.239.14.126116.239.14.12730
117116.239.14.128/27116.239.14.129 to 116.239.14.158116.239.14.15930
118116.239.14.160/27116.239.14.161 to 116.239.14.190116.239.14.19130
119116.239.14.192/27116.239.14.193 to 116.239.14.222116.239.14.22330
120116.239.14.224/27116.239.14.225 to 116.239.14.254116.239.14.25530
121116.239.15.0/27116.239.15.1 to 116.239.15.30116.239.15.3130
122116.239.15.32/27116.239.15.33 to 116.239.15.62116.239.15.6330
123116.239.15.64/27116.239.15.65 to 116.239.15.94116.239.15.9530
124116.239.15.96/27116.239.15.97 to 116.239.15.126116.239.15.12730
125116.239.15.128/27116.239.15.129 to 116.239.15.158116.239.15.15930
126116.239.15.160/27116.239.15.161 to 116.239.15.190116.239.15.19130
127116.239.15.192/27116.239.15.193 to 116.239.15.222116.239.15.22330
128116.239.15.224/27116.239.15.225 to 116.239.15.254116.239.15.25530
129116.239.16.0/27116.239.16.1 to 116.239.16.30116.239.16.3130
130116.239.16.32/27116.239.16.33 to 116.239.16.62116.239.16.6330
131116.239.16.64/27116.239.16.65 to 116.239.16.94116.239.16.9530
132116.239.16.96/27116.239.16.97 to 116.239.16.126116.239.16.12730
133116.239.16.128/27116.239.16.129 to 116.239.16.158116.239.16.15930
134116.239.16.160/27116.239.16.161 to 116.239.16.190116.239.16.19130
135116.239.16.192/27116.239.16.193 to 116.239.16.222116.239.16.22330
136116.239.16.224/27116.239.16.225 to 116.239.16.254116.239.16.25530
137116.239.17.0/27116.239.17.1 to 116.239.17.30116.239.17.3130
138116.239.17.32/27116.239.17.33 to 116.239.17.62116.239.17.6330
139116.239.17.64/27116.239.17.65 to 116.239.17.94116.239.17.9530
140116.239.17.96/27116.239.17.97 to 116.239.17.126116.239.17.12730
141116.239.17.128/27116.239.17.129 to 116.239.17.158116.239.17.15930
142116.239.17.160/27116.239.17.161 to 116.239.17.190116.239.17.19130
143116.239.17.192/27116.239.17.193 to 116.239.17.222116.239.17.22330
144116.239.17.224/27116.239.17.225 to 116.239.17.254116.239.17.25530
145116.239.18.0/27116.239.18.1 to 116.239.18.30116.239.18.3130
146116.239.18.32/27116.239.18.33 to 116.239.18.62116.239.18.6330
147116.239.18.64/27116.239.18.65 to 116.239.18.94116.239.18.9530
148116.239.18.96/27116.239.18.97 to 116.239.18.126116.239.18.12730
149116.239.18.128/27116.239.18.129 to 116.239.18.158116.239.18.15930
150116.239.18.160/27116.239.18.161 to 116.239.18.190116.239.18.19130
151116.239.18.192/27116.239.18.193 to 116.239.18.222116.239.18.22330
152116.239.18.224/27116.239.18.225 to 116.239.18.254116.239.18.25530
153116.239.19.0/27116.239.19.1 to 116.239.19.30116.239.19.3130
154116.239.19.32/27116.239.19.33 to 116.239.19.62116.239.19.6330
155116.239.19.64/27116.239.19.65 to 116.239.19.94116.239.19.9530
156116.239.19.96/27116.239.19.97 to 116.239.19.126116.239.19.12730
157116.239.19.128/27116.239.19.129 to 116.239.19.158116.239.19.15930
158116.239.19.160/27116.239.19.161 to 116.239.19.190116.239.19.19130
159116.239.19.192/27116.239.19.193 to 116.239.19.222116.239.19.22330
160116.239.19.224/27116.239.19.225 to 116.239.19.254116.239.19.25530
161116.239.20.0/27116.239.20.1 to 116.239.20.30116.239.20.3130
162116.239.20.32/27116.239.20.33 to 116.239.20.62116.239.20.6330
163116.239.20.64/27116.239.20.65 to 116.239.20.94116.239.20.9530
164116.239.20.96/27116.239.20.97 to 116.239.20.126116.239.20.12730
165116.239.20.128/27116.239.20.129 to 116.239.20.158116.239.20.15930
166116.239.20.160/27116.239.20.161 to 116.239.20.190116.239.20.19130
167116.239.20.192/27116.239.20.193 to 116.239.20.222116.239.20.22330
168116.239.20.224/27116.239.20.225 to 116.239.20.254116.239.20.25530
169116.239.21.0/27116.239.21.1 to 116.239.21.30116.239.21.3130
170116.239.21.32/27116.239.21.33 to 116.239.21.62116.239.21.6330
171116.239.21.64/27116.239.21.65 to 116.239.21.94116.239.21.9530
172116.239.21.96/27116.239.21.97 to 116.239.21.126116.239.21.12730
173116.239.21.128/27116.239.21.129 to 116.239.21.158116.239.21.15930
174116.239.21.160/27116.239.21.161 to 116.239.21.190116.239.21.19130
175116.239.21.192/27116.239.21.193 to 116.239.21.222116.239.21.22330
176116.239.21.224/27116.239.21.225 to 116.239.21.254116.239.21.25530
177116.239.22.0/27116.239.22.1 to 116.239.22.30116.239.22.3130
178116.239.22.32/27116.239.22.33 to 116.239.22.62116.239.22.6330
179116.239.22.64/27116.239.22.65 to 116.239.22.94116.239.22.9530
180116.239.22.96/27116.239.22.97 to 116.239.22.126116.239.22.12730
181116.239.22.128/27116.239.22.129 to 116.239.22.158116.239.22.15930
182116.239.22.160/27116.239.22.161 to 116.239.22.190116.239.22.19130
183116.239.22.192/27116.239.22.193 to 116.239.22.222116.239.22.22330
184116.239.22.224/27116.239.22.225 to 116.239.22.254116.239.22.25530
185116.239.23.0/27116.239.23.1 to 116.239.23.30116.239.23.3130
186116.239.23.32/27116.239.23.33 to 116.239.23.62116.239.23.6330
187116.239.23.64/27116.239.23.65 to 116.239.23.94116.239.23.9530
188116.239.23.96/27116.239.23.97 to 116.239.23.126116.239.23.12730
189116.239.23.128/27116.239.23.129 to 116.239.23.158116.239.23.15930
190116.239.23.160/27116.239.23.161 to 116.239.23.190116.239.23.19130
191116.239.23.192/27116.239.23.193 to 116.239.23.222116.239.23.22330
192116.239.23.224/27116.239.23.225 to 116.239.23.254116.239.23.25530
193116.239.24.0/27116.239.24.1 to 116.239.24.30116.239.24.3130
194116.239.24.32/27116.239.24.33 to 116.239.24.62116.239.24.6330
195116.239.24.64/27116.239.24.65 to 116.239.24.94116.239.24.9530
196116.239.24.96/27116.239.24.97 to 116.239.24.126116.239.24.12730
197116.239.24.128/27116.239.24.129 to 116.239.24.158116.239.24.15930
198116.239.24.160/27116.239.24.161 to 116.239.24.190116.239.24.19130
199116.239.24.192/27116.239.24.193 to 116.239.24.222116.239.24.22330
200116.239.24.224/27116.239.24.225 to 116.239.24.254116.239.24.25530
201116.239.25.0/27116.239.25.1 to 116.239.25.30116.239.25.3130
202116.239.25.32/27116.239.25.33 to 116.239.25.62116.239.25.6330
203116.239.25.64/27116.239.25.65 to 116.239.25.94116.239.25.9530
204116.239.25.96/27116.239.25.97 to 116.239.25.126116.239.25.12730
205116.239.25.128/27116.239.25.129 to 116.239.25.158116.239.25.15930
206116.239.25.160/27116.239.25.161 to 116.239.25.190116.239.25.19130
207116.239.25.192/27116.239.25.193 to 116.239.25.222116.239.25.22330
208116.239.25.224/27116.239.25.225 to 116.239.25.254116.239.25.25530
209116.239.26.0/27116.239.26.1 to 116.239.26.30116.239.26.3130
210116.239.26.32/27116.239.26.33 to 116.239.26.62116.239.26.6330
211116.239.26.64/27116.239.26.65 to 116.239.26.94116.239.26.9530
212116.239.26.96/27116.239.26.97 to 116.239.26.126116.239.26.12730
213116.239.26.128/27116.239.26.129 to 116.239.26.158116.239.26.15930
214116.239.26.160/27116.239.26.161 to 116.239.26.190116.239.26.19130
215116.239.26.192/27116.239.26.193 to 116.239.26.222116.239.26.22330
216116.239.26.224/27116.239.26.225 to 116.239.26.254116.239.26.25530
217116.239.27.0/27116.239.27.1 to 116.239.27.30116.239.27.3130
218116.239.27.32/27116.239.27.33 to 116.239.27.62116.239.27.6330
219116.239.27.64/27116.239.27.65 to 116.239.27.94116.239.27.9530
220116.239.27.96/27116.239.27.97 to 116.239.27.126116.239.27.12730
221116.239.27.128/27116.239.27.129 to 116.239.27.158116.239.27.15930
222116.239.27.160/27116.239.27.161 to 116.239.27.190116.239.27.19130
223116.239.27.192/27116.239.27.193 to 116.239.27.222116.239.27.22330
224116.239.27.224/27116.239.27.225 to 116.239.27.254116.239.27.25530
225116.239.28.0/27116.239.28.1 to 116.239.28.30116.239.28.3130
226116.239.28.32/27116.239.28.33 to 116.239.28.62116.239.28.6330
227116.239.28.64/27116.239.28.65 to 116.239.28.94116.239.28.9530
228116.239.28.96/27116.239.28.97 to 116.239.28.126116.239.28.12730
229116.239.28.128/27116.239.28.129 to 116.239.28.158116.239.28.15930
230116.239.28.160/27116.239.28.161 to 116.239.28.190116.239.28.19130
231116.239.28.192/27116.239.28.193 to 116.239.28.222116.239.28.22330
232116.239.28.224/27116.239.28.225 to 116.239.28.254116.239.28.25530
233116.239.29.0/27116.239.29.1 to 116.239.29.30116.239.29.3130
234116.239.29.32/27116.239.29.33 to 116.239.29.62116.239.29.6330
235116.239.29.64/27116.239.29.65 to 116.239.29.94116.239.29.9530
236116.239.29.96/27116.239.29.97 to 116.239.29.126116.239.29.12730
237116.239.29.128/27116.239.29.129 to 116.239.29.158116.239.29.15930
238116.239.29.160/27116.239.29.161 to 116.239.29.190116.239.29.19130
239116.239.29.192/27116.239.29.193 to 116.239.29.222116.239.29.22330
240116.239.29.224/27116.239.29.225 to 116.239.29.254116.239.29.25530
241116.239.30.0/27116.239.30.1 to 116.239.30.30116.239.30.3130
242116.239.30.32/27116.239.30.33 to 116.239.30.62116.239.30.6330
243116.239.30.64/27116.239.30.65 to 116.239.30.94116.239.30.9530
244116.239.30.96/27116.239.30.97 to 116.239.30.126116.239.30.12730
245116.239.30.128/27116.239.30.129 to 116.239.30.158116.239.30.15930
246116.239.30.160/27116.239.30.161 to 116.239.30.190116.239.30.19130
247116.239.30.192/27116.239.30.193 to 116.239.30.222116.239.30.22330
248116.239.30.224/27116.239.30.225 to 116.239.30.254116.239.30.25530
249116.239.31.0/27116.239.31.1 to 116.239.31.30116.239.31.3130
250116.239.31.32/27116.239.31.33 to 116.239.31.62116.239.31.6330
251116.239.31.64/27116.239.31.65 to 116.239.31.94116.239.31.9530
252116.239.31.96/27116.239.31.97 to 116.239.31.126116.239.31.12730
253116.239.31.128/27116.239.31.129 to 116.239.31.158116.239.31.15930
254116.239.31.160/27116.239.31.161 to 116.239.31.190116.239.31.19130
255116.239.31.192/27116.239.31.193 to 116.239.31.222116.239.31.22330
256116.239.31.224/27116.239.31.225 to 116.239.31.254116.239.31.25530

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.