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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.

Network126.136.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
126.136.0.0
Broadcast address
126.136.255.255
First usable
126.136.0.1
Last usable
126.136.255.254
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
A (default /8)
As numbers
Hex 7E880000 · Integer 2122842112 to 2122907647
Reverse DNS zone
136.126.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01111110.10001000..00000000.00000000126.136.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network01111110.10001000..00000000.00000000126.136.0.0
Broadcast01111110.10001000..11111111.11111111126.136.255.255
Split into smaller subnets/27
/17 (2)/18 (4)/19 (8)/20 (16)/21 (32)/22 (64)/23 (128)/24 (256)/25 (512)/26 (1,024)/27 (2,048)/28 (4,096)

126.136.0.0/16 makes 2,048 subnets of /27; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1126.136.0.0/27126.136.0.1 to 126.136.0.30126.136.0.3130
2126.136.0.32/27126.136.0.33 to 126.136.0.62126.136.0.6330
3126.136.0.64/27126.136.0.65 to 126.136.0.94126.136.0.9530
4126.136.0.96/27126.136.0.97 to 126.136.0.126126.136.0.12730
5126.136.0.128/27126.136.0.129 to 126.136.0.158126.136.0.15930
6126.136.0.160/27126.136.0.161 to 126.136.0.190126.136.0.19130
7126.136.0.192/27126.136.0.193 to 126.136.0.222126.136.0.22330
8126.136.0.224/27126.136.0.225 to 126.136.0.254126.136.0.25530
9126.136.1.0/27126.136.1.1 to 126.136.1.30126.136.1.3130
10126.136.1.32/27126.136.1.33 to 126.136.1.62126.136.1.6330
11126.136.1.64/27126.136.1.65 to 126.136.1.94126.136.1.9530
12126.136.1.96/27126.136.1.97 to 126.136.1.126126.136.1.12730
13126.136.1.128/27126.136.1.129 to 126.136.1.158126.136.1.15930
14126.136.1.160/27126.136.1.161 to 126.136.1.190126.136.1.19130
15126.136.1.192/27126.136.1.193 to 126.136.1.222126.136.1.22330
16126.136.1.224/27126.136.1.225 to 126.136.1.254126.136.1.25530
17126.136.2.0/27126.136.2.1 to 126.136.2.30126.136.2.3130
18126.136.2.32/27126.136.2.33 to 126.136.2.62126.136.2.6330
19126.136.2.64/27126.136.2.65 to 126.136.2.94126.136.2.9530
20126.136.2.96/27126.136.2.97 to 126.136.2.126126.136.2.12730
21126.136.2.128/27126.136.2.129 to 126.136.2.158126.136.2.15930
22126.136.2.160/27126.136.2.161 to 126.136.2.190126.136.2.19130
23126.136.2.192/27126.136.2.193 to 126.136.2.222126.136.2.22330
24126.136.2.224/27126.136.2.225 to 126.136.2.254126.136.2.25530
25126.136.3.0/27126.136.3.1 to 126.136.3.30126.136.3.3130
26126.136.3.32/27126.136.3.33 to 126.136.3.62126.136.3.6330
27126.136.3.64/27126.136.3.65 to 126.136.3.94126.136.3.9530
28126.136.3.96/27126.136.3.97 to 126.136.3.126126.136.3.12730
29126.136.3.128/27126.136.3.129 to 126.136.3.158126.136.3.15930
30126.136.3.160/27126.136.3.161 to 126.136.3.190126.136.3.19130
31126.136.3.192/27126.136.3.193 to 126.136.3.222126.136.3.22330
32126.136.3.224/27126.136.3.225 to 126.136.3.254126.136.3.25530
33126.136.4.0/27126.136.4.1 to 126.136.4.30126.136.4.3130
34126.136.4.32/27126.136.4.33 to 126.136.4.62126.136.4.6330
35126.136.4.64/27126.136.4.65 to 126.136.4.94126.136.4.9530
36126.136.4.96/27126.136.4.97 to 126.136.4.126126.136.4.12730
37126.136.4.128/27126.136.4.129 to 126.136.4.158126.136.4.15930
38126.136.4.160/27126.136.4.161 to 126.136.4.190126.136.4.19130
39126.136.4.192/27126.136.4.193 to 126.136.4.222126.136.4.22330
40126.136.4.224/27126.136.4.225 to 126.136.4.254126.136.4.25530
41126.136.5.0/27126.136.5.1 to 126.136.5.30126.136.5.3130
42126.136.5.32/27126.136.5.33 to 126.136.5.62126.136.5.6330
43126.136.5.64/27126.136.5.65 to 126.136.5.94126.136.5.9530
44126.136.5.96/27126.136.5.97 to 126.136.5.126126.136.5.12730
45126.136.5.128/27126.136.5.129 to 126.136.5.158126.136.5.15930
46126.136.5.160/27126.136.5.161 to 126.136.5.190126.136.5.19130
47126.136.5.192/27126.136.5.193 to 126.136.5.222126.136.5.22330
48126.136.5.224/27126.136.5.225 to 126.136.5.254126.136.5.25530
49126.136.6.0/27126.136.6.1 to 126.136.6.30126.136.6.3130
50126.136.6.32/27126.136.6.33 to 126.136.6.62126.136.6.6330
51126.136.6.64/27126.136.6.65 to 126.136.6.94126.136.6.9530
52126.136.6.96/27126.136.6.97 to 126.136.6.126126.136.6.12730
53126.136.6.128/27126.136.6.129 to 126.136.6.158126.136.6.15930
54126.136.6.160/27126.136.6.161 to 126.136.6.190126.136.6.19130
55126.136.6.192/27126.136.6.193 to 126.136.6.222126.136.6.22330
56126.136.6.224/27126.136.6.225 to 126.136.6.254126.136.6.25530
57126.136.7.0/27126.136.7.1 to 126.136.7.30126.136.7.3130
58126.136.7.32/27126.136.7.33 to 126.136.7.62126.136.7.6330
59126.136.7.64/27126.136.7.65 to 126.136.7.94126.136.7.9530
60126.136.7.96/27126.136.7.97 to 126.136.7.126126.136.7.12730
61126.136.7.128/27126.136.7.129 to 126.136.7.158126.136.7.15930
62126.136.7.160/27126.136.7.161 to 126.136.7.190126.136.7.19130
63126.136.7.192/27126.136.7.193 to 126.136.7.222126.136.7.22330
64126.136.7.224/27126.136.7.225 to 126.136.7.254126.136.7.25530
65126.136.8.0/27126.136.8.1 to 126.136.8.30126.136.8.3130
66126.136.8.32/27126.136.8.33 to 126.136.8.62126.136.8.6330
67126.136.8.64/27126.136.8.65 to 126.136.8.94126.136.8.9530
68126.136.8.96/27126.136.8.97 to 126.136.8.126126.136.8.12730
69126.136.8.128/27126.136.8.129 to 126.136.8.158126.136.8.15930
70126.136.8.160/27126.136.8.161 to 126.136.8.190126.136.8.19130
71126.136.8.192/27126.136.8.193 to 126.136.8.222126.136.8.22330
72126.136.8.224/27126.136.8.225 to 126.136.8.254126.136.8.25530
73126.136.9.0/27126.136.9.1 to 126.136.9.30126.136.9.3130
74126.136.9.32/27126.136.9.33 to 126.136.9.62126.136.9.6330
75126.136.9.64/27126.136.9.65 to 126.136.9.94126.136.9.9530
76126.136.9.96/27126.136.9.97 to 126.136.9.126126.136.9.12730
77126.136.9.128/27126.136.9.129 to 126.136.9.158126.136.9.15930
78126.136.9.160/27126.136.9.161 to 126.136.9.190126.136.9.19130
79126.136.9.192/27126.136.9.193 to 126.136.9.222126.136.9.22330
80126.136.9.224/27126.136.9.225 to 126.136.9.254126.136.9.25530
81126.136.10.0/27126.136.10.1 to 126.136.10.30126.136.10.3130
82126.136.10.32/27126.136.10.33 to 126.136.10.62126.136.10.6330
83126.136.10.64/27126.136.10.65 to 126.136.10.94126.136.10.9530
84126.136.10.96/27126.136.10.97 to 126.136.10.126126.136.10.12730
85126.136.10.128/27126.136.10.129 to 126.136.10.158126.136.10.15930
86126.136.10.160/27126.136.10.161 to 126.136.10.190126.136.10.19130
87126.136.10.192/27126.136.10.193 to 126.136.10.222126.136.10.22330
88126.136.10.224/27126.136.10.225 to 126.136.10.254126.136.10.25530
89126.136.11.0/27126.136.11.1 to 126.136.11.30126.136.11.3130
90126.136.11.32/27126.136.11.33 to 126.136.11.62126.136.11.6330
91126.136.11.64/27126.136.11.65 to 126.136.11.94126.136.11.9530
92126.136.11.96/27126.136.11.97 to 126.136.11.126126.136.11.12730
93126.136.11.128/27126.136.11.129 to 126.136.11.158126.136.11.15930
94126.136.11.160/27126.136.11.161 to 126.136.11.190126.136.11.19130
95126.136.11.192/27126.136.11.193 to 126.136.11.222126.136.11.22330
96126.136.11.224/27126.136.11.225 to 126.136.11.254126.136.11.25530
97126.136.12.0/27126.136.12.1 to 126.136.12.30126.136.12.3130
98126.136.12.32/27126.136.12.33 to 126.136.12.62126.136.12.6330
99126.136.12.64/27126.136.12.65 to 126.136.12.94126.136.12.9530
100126.136.12.96/27126.136.12.97 to 126.136.12.126126.136.12.12730
101126.136.12.128/27126.136.12.129 to 126.136.12.158126.136.12.15930
102126.136.12.160/27126.136.12.161 to 126.136.12.190126.136.12.19130
103126.136.12.192/27126.136.12.193 to 126.136.12.222126.136.12.22330
104126.136.12.224/27126.136.12.225 to 126.136.12.254126.136.12.25530
105126.136.13.0/27126.136.13.1 to 126.136.13.30126.136.13.3130
106126.136.13.32/27126.136.13.33 to 126.136.13.62126.136.13.6330
107126.136.13.64/27126.136.13.65 to 126.136.13.94126.136.13.9530
108126.136.13.96/27126.136.13.97 to 126.136.13.126126.136.13.12730
109126.136.13.128/27126.136.13.129 to 126.136.13.158126.136.13.15930
110126.136.13.160/27126.136.13.161 to 126.136.13.190126.136.13.19130
111126.136.13.192/27126.136.13.193 to 126.136.13.222126.136.13.22330
112126.136.13.224/27126.136.13.225 to 126.136.13.254126.136.13.25530
113126.136.14.0/27126.136.14.1 to 126.136.14.30126.136.14.3130
114126.136.14.32/27126.136.14.33 to 126.136.14.62126.136.14.6330
115126.136.14.64/27126.136.14.65 to 126.136.14.94126.136.14.9530
116126.136.14.96/27126.136.14.97 to 126.136.14.126126.136.14.12730
117126.136.14.128/27126.136.14.129 to 126.136.14.158126.136.14.15930
118126.136.14.160/27126.136.14.161 to 126.136.14.190126.136.14.19130
119126.136.14.192/27126.136.14.193 to 126.136.14.222126.136.14.22330
120126.136.14.224/27126.136.14.225 to 126.136.14.254126.136.14.25530
121126.136.15.0/27126.136.15.1 to 126.136.15.30126.136.15.3130
122126.136.15.32/27126.136.15.33 to 126.136.15.62126.136.15.6330
123126.136.15.64/27126.136.15.65 to 126.136.15.94126.136.15.9530
124126.136.15.96/27126.136.15.97 to 126.136.15.126126.136.15.12730
125126.136.15.128/27126.136.15.129 to 126.136.15.158126.136.15.15930
126126.136.15.160/27126.136.15.161 to 126.136.15.190126.136.15.19130
127126.136.15.192/27126.136.15.193 to 126.136.15.222126.136.15.22330
128126.136.15.224/27126.136.15.225 to 126.136.15.254126.136.15.25530
129126.136.16.0/27126.136.16.1 to 126.136.16.30126.136.16.3130
130126.136.16.32/27126.136.16.33 to 126.136.16.62126.136.16.6330
131126.136.16.64/27126.136.16.65 to 126.136.16.94126.136.16.9530
132126.136.16.96/27126.136.16.97 to 126.136.16.126126.136.16.12730
133126.136.16.128/27126.136.16.129 to 126.136.16.158126.136.16.15930
134126.136.16.160/27126.136.16.161 to 126.136.16.190126.136.16.19130
135126.136.16.192/27126.136.16.193 to 126.136.16.222126.136.16.22330
136126.136.16.224/27126.136.16.225 to 126.136.16.254126.136.16.25530
137126.136.17.0/27126.136.17.1 to 126.136.17.30126.136.17.3130
138126.136.17.32/27126.136.17.33 to 126.136.17.62126.136.17.6330
139126.136.17.64/27126.136.17.65 to 126.136.17.94126.136.17.9530
140126.136.17.96/27126.136.17.97 to 126.136.17.126126.136.17.12730
141126.136.17.128/27126.136.17.129 to 126.136.17.158126.136.17.15930
142126.136.17.160/27126.136.17.161 to 126.136.17.190126.136.17.19130
143126.136.17.192/27126.136.17.193 to 126.136.17.222126.136.17.22330
144126.136.17.224/27126.136.17.225 to 126.136.17.254126.136.17.25530
145126.136.18.0/27126.136.18.1 to 126.136.18.30126.136.18.3130
146126.136.18.32/27126.136.18.33 to 126.136.18.62126.136.18.6330
147126.136.18.64/27126.136.18.65 to 126.136.18.94126.136.18.9530
148126.136.18.96/27126.136.18.97 to 126.136.18.126126.136.18.12730
149126.136.18.128/27126.136.18.129 to 126.136.18.158126.136.18.15930
150126.136.18.160/27126.136.18.161 to 126.136.18.190126.136.18.19130
151126.136.18.192/27126.136.18.193 to 126.136.18.222126.136.18.22330
152126.136.18.224/27126.136.18.225 to 126.136.18.254126.136.18.25530
153126.136.19.0/27126.136.19.1 to 126.136.19.30126.136.19.3130
154126.136.19.32/27126.136.19.33 to 126.136.19.62126.136.19.6330
155126.136.19.64/27126.136.19.65 to 126.136.19.94126.136.19.9530
156126.136.19.96/27126.136.19.97 to 126.136.19.126126.136.19.12730
157126.136.19.128/27126.136.19.129 to 126.136.19.158126.136.19.15930
158126.136.19.160/27126.136.19.161 to 126.136.19.190126.136.19.19130
159126.136.19.192/27126.136.19.193 to 126.136.19.222126.136.19.22330
160126.136.19.224/27126.136.19.225 to 126.136.19.254126.136.19.25530
161126.136.20.0/27126.136.20.1 to 126.136.20.30126.136.20.3130
162126.136.20.32/27126.136.20.33 to 126.136.20.62126.136.20.6330
163126.136.20.64/27126.136.20.65 to 126.136.20.94126.136.20.9530
164126.136.20.96/27126.136.20.97 to 126.136.20.126126.136.20.12730
165126.136.20.128/27126.136.20.129 to 126.136.20.158126.136.20.15930
166126.136.20.160/27126.136.20.161 to 126.136.20.190126.136.20.19130
167126.136.20.192/27126.136.20.193 to 126.136.20.222126.136.20.22330
168126.136.20.224/27126.136.20.225 to 126.136.20.254126.136.20.25530
169126.136.21.0/27126.136.21.1 to 126.136.21.30126.136.21.3130
170126.136.21.32/27126.136.21.33 to 126.136.21.62126.136.21.6330
171126.136.21.64/27126.136.21.65 to 126.136.21.94126.136.21.9530
172126.136.21.96/27126.136.21.97 to 126.136.21.126126.136.21.12730
173126.136.21.128/27126.136.21.129 to 126.136.21.158126.136.21.15930
174126.136.21.160/27126.136.21.161 to 126.136.21.190126.136.21.19130
175126.136.21.192/27126.136.21.193 to 126.136.21.222126.136.21.22330
176126.136.21.224/27126.136.21.225 to 126.136.21.254126.136.21.25530
177126.136.22.0/27126.136.22.1 to 126.136.22.30126.136.22.3130
178126.136.22.32/27126.136.22.33 to 126.136.22.62126.136.22.6330
179126.136.22.64/27126.136.22.65 to 126.136.22.94126.136.22.9530
180126.136.22.96/27126.136.22.97 to 126.136.22.126126.136.22.12730
181126.136.22.128/27126.136.22.129 to 126.136.22.158126.136.22.15930
182126.136.22.160/27126.136.22.161 to 126.136.22.190126.136.22.19130
183126.136.22.192/27126.136.22.193 to 126.136.22.222126.136.22.22330
184126.136.22.224/27126.136.22.225 to 126.136.22.254126.136.22.25530
185126.136.23.0/27126.136.23.1 to 126.136.23.30126.136.23.3130
186126.136.23.32/27126.136.23.33 to 126.136.23.62126.136.23.6330
187126.136.23.64/27126.136.23.65 to 126.136.23.94126.136.23.9530
188126.136.23.96/27126.136.23.97 to 126.136.23.126126.136.23.12730
189126.136.23.128/27126.136.23.129 to 126.136.23.158126.136.23.15930
190126.136.23.160/27126.136.23.161 to 126.136.23.190126.136.23.19130
191126.136.23.192/27126.136.23.193 to 126.136.23.222126.136.23.22330
192126.136.23.224/27126.136.23.225 to 126.136.23.254126.136.23.25530
193126.136.24.0/27126.136.24.1 to 126.136.24.30126.136.24.3130
194126.136.24.32/27126.136.24.33 to 126.136.24.62126.136.24.6330
195126.136.24.64/27126.136.24.65 to 126.136.24.94126.136.24.9530
196126.136.24.96/27126.136.24.97 to 126.136.24.126126.136.24.12730
197126.136.24.128/27126.136.24.129 to 126.136.24.158126.136.24.15930
198126.136.24.160/27126.136.24.161 to 126.136.24.190126.136.24.19130
199126.136.24.192/27126.136.24.193 to 126.136.24.222126.136.24.22330
200126.136.24.224/27126.136.24.225 to 126.136.24.254126.136.24.25530
201126.136.25.0/27126.136.25.1 to 126.136.25.30126.136.25.3130
202126.136.25.32/27126.136.25.33 to 126.136.25.62126.136.25.6330
203126.136.25.64/27126.136.25.65 to 126.136.25.94126.136.25.9530
204126.136.25.96/27126.136.25.97 to 126.136.25.126126.136.25.12730
205126.136.25.128/27126.136.25.129 to 126.136.25.158126.136.25.15930
206126.136.25.160/27126.136.25.161 to 126.136.25.190126.136.25.19130
207126.136.25.192/27126.136.25.193 to 126.136.25.222126.136.25.22330
208126.136.25.224/27126.136.25.225 to 126.136.25.254126.136.25.25530
209126.136.26.0/27126.136.26.1 to 126.136.26.30126.136.26.3130
210126.136.26.32/27126.136.26.33 to 126.136.26.62126.136.26.6330
211126.136.26.64/27126.136.26.65 to 126.136.26.94126.136.26.9530
212126.136.26.96/27126.136.26.97 to 126.136.26.126126.136.26.12730
213126.136.26.128/27126.136.26.129 to 126.136.26.158126.136.26.15930
214126.136.26.160/27126.136.26.161 to 126.136.26.190126.136.26.19130
215126.136.26.192/27126.136.26.193 to 126.136.26.222126.136.26.22330
216126.136.26.224/27126.136.26.225 to 126.136.26.254126.136.26.25530
217126.136.27.0/27126.136.27.1 to 126.136.27.30126.136.27.3130
218126.136.27.32/27126.136.27.33 to 126.136.27.62126.136.27.6330
219126.136.27.64/27126.136.27.65 to 126.136.27.94126.136.27.9530
220126.136.27.96/27126.136.27.97 to 126.136.27.126126.136.27.12730
221126.136.27.128/27126.136.27.129 to 126.136.27.158126.136.27.15930
222126.136.27.160/27126.136.27.161 to 126.136.27.190126.136.27.19130
223126.136.27.192/27126.136.27.193 to 126.136.27.222126.136.27.22330
224126.136.27.224/27126.136.27.225 to 126.136.27.254126.136.27.25530
225126.136.28.0/27126.136.28.1 to 126.136.28.30126.136.28.3130
226126.136.28.32/27126.136.28.33 to 126.136.28.62126.136.28.6330
227126.136.28.64/27126.136.28.65 to 126.136.28.94126.136.28.9530
228126.136.28.96/27126.136.28.97 to 126.136.28.126126.136.28.12730
229126.136.28.128/27126.136.28.129 to 126.136.28.158126.136.28.15930
230126.136.28.160/27126.136.28.161 to 126.136.28.190126.136.28.19130
231126.136.28.192/27126.136.28.193 to 126.136.28.222126.136.28.22330
232126.136.28.224/27126.136.28.225 to 126.136.28.254126.136.28.25530
233126.136.29.0/27126.136.29.1 to 126.136.29.30126.136.29.3130
234126.136.29.32/27126.136.29.33 to 126.136.29.62126.136.29.6330
235126.136.29.64/27126.136.29.65 to 126.136.29.94126.136.29.9530
236126.136.29.96/27126.136.29.97 to 126.136.29.126126.136.29.12730
237126.136.29.128/27126.136.29.129 to 126.136.29.158126.136.29.15930
238126.136.29.160/27126.136.29.161 to 126.136.29.190126.136.29.19130
239126.136.29.192/27126.136.29.193 to 126.136.29.222126.136.29.22330
240126.136.29.224/27126.136.29.225 to 126.136.29.254126.136.29.25530
241126.136.30.0/27126.136.30.1 to 126.136.30.30126.136.30.3130
242126.136.30.32/27126.136.30.33 to 126.136.30.62126.136.30.6330
243126.136.30.64/27126.136.30.65 to 126.136.30.94126.136.30.9530
244126.136.30.96/27126.136.30.97 to 126.136.30.126126.136.30.12730
245126.136.30.128/27126.136.30.129 to 126.136.30.158126.136.30.15930
246126.136.30.160/27126.136.30.161 to 126.136.30.190126.136.30.19130
247126.136.30.192/27126.136.30.193 to 126.136.30.222126.136.30.22330
248126.136.30.224/27126.136.30.225 to 126.136.30.254126.136.30.25530
249126.136.31.0/27126.136.31.1 to 126.136.31.30126.136.31.3130
250126.136.31.32/27126.136.31.33 to 126.136.31.62126.136.31.6330
251126.136.31.64/27126.136.31.65 to 126.136.31.94126.136.31.9530
252126.136.31.96/27126.136.31.97 to 126.136.31.126126.136.31.12730
253126.136.31.128/27126.136.31.129 to 126.136.31.158126.136.31.15930
254126.136.31.160/27126.136.31.161 to 126.136.31.190126.136.31.19130
255126.136.31.192/27126.136.31.193 to 126.136.31.222126.136.31.22330
256126.136.31.224/27126.136.31.225 to 126.136.31.254126.136.31.25530

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.