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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.

Network126.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
126.0.0.0
Broadcast address
126.255.255.255
First usable
126.0.0.1
Last usable
126.255.255.254
Usable hosts
16,777,214 (16,777,216 less the network and broadcast addresses)
Subnet mask
255.0.0.0
Wildcard mask
0.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/8
Type
Public public
Old class
A (default /8)
As numbers
Hex 7E000000 · Integer 2113929216 to 2130706431
Reverse DNS zone
126.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01111110..00000000.00000000.00000000126.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network01111110..00000000.00000000.00000000126.0.0.0
Broadcast01111110..11111111.11111111.11111111126.255.255.255
Split into smaller subnets/19
/9 (2)/10 (4)/11 (8)/12 (16)/13 (32)/14 (64)/15 (128)/16 (256)/17 (512)/18 (1,024)/19 (2,048)/20 (4,096)

126.0.0.0/8 makes 2,048 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1126.0.0.0/19126.0.0.1 to 126.0.31.254126.0.31.2558,190
2126.0.32.0/19126.0.32.1 to 126.0.63.254126.0.63.2558,190
3126.0.64.0/19126.0.64.1 to 126.0.95.254126.0.95.2558,190
4126.0.96.0/19126.0.96.1 to 126.0.127.254126.0.127.2558,190
5126.0.128.0/19126.0.128.1 to 126.0.159.254126.0.159.2558,190
6126.0.160.0/19126.0.160.1 to 126.0.191.254126.0.191.2558,190
7126.0.192.0/19126.0.192.1 to 126.0.223.254126.0.223.2558,190
8126.0.224.0/19126.0.224.1 to 126.0.255.254126.0.255.2558,190
9126.1.0.0/19126.1.0.1 to 126.1.31.254126.1.31.2558,190
10126.1.32.0/19126.1.32.1 to 126.1.63.254126.1.63.2558,190
11126.1.64.0/19126.1.64.1 to 126.1.95.254126.1.95.2558,190
12126.1.96.0/19126.1.96.1 to 126.1.127.254126.1.127.2558,190
13126.1.128.0/19126.1.128.1 to 126.1.159.254126.1.159.2558,190
14126.1.160.0/19126.1.160.1 to 126.1.191.254126.1.191.2558,190
15126.1.192.0/19126.1.192.1 to 126.1.223.254126.1.223.2558,190
16126.1.224.0/19126.1.224.1 to 126.1.255.254126.1.255.2558,190
17126.2.0.0/19126.2.0.1 to 126.2.31.254126.2.31.2558,190
18126.2.32.0/19126.2.32.1 to 126.2.63.254126.2.63.2558,190
19126.2.64.0/19126.2.64.1 to 126.2.95.254126.2.95.2558,190
20126.2.96.0/19126.2.96.1 to 126.2.127.254126.2.127.2558,190
21126.2.128.0/19126.2.128.1 to 126.2.159.254126.2.159.2558,190
22126.2.160.0/19126.2.160.1 to 126.2.191.254126.2.191.2558,190
23126.2.192.0/19126.2.192.1 to 126.2.223.254126.2.223.2558,190
24126.2.224.0/19126.2.224.1 to 126.2.255.254126.2.255.2558,190
25126.3.0.0/19126.3.0.1 to 126.3.31.254126.3.31.2558,190
26126.3.32.0/19126.3.32.1 to 126.3.63.254126.3.63.2558,190
27126.3.64.0/19126.3.64.1 to 126.3.95.254126.3.95.2558,190
28126.3.96.0/19126.3.96.1 to 126.3.127.254126.3.127.2558,190
29126.3.128.0/19126.3.128.1 to 126.3.159.254126.3.159.2558,190
30126.3.160.0/19126.3.160.1 to 126.3.191.254126.3.191.2558,190
31126.3.192.0/19126.3.192.1 to 126.3.223.254126.3.223.2558,190
32126.3.224.0/19126.3.224.1 to 126.3.255.254126.3.255.2558,190
33126.4.0.0/19126.4.0.1 to 126.4.31.254126.4.31.2558,190
34126.4.32.0/19126.4.32.1 to 126.4.63.254126.4.63.2558,190
35126.4.64.0/19126.4.64.1 to 126.4.95.254126.4.95.2558,190
36126.4.96.0/19126.4.96.1 to 126.4.127.254126.4.127.2558,190
37126.4.128.0/19126.4.128.1 to 126.4.159.254126.4.159.2558,190
38126.4.160.0/19126.4.160.1 to 126.4.191.254126.4.191.2558,190
39126.4.192.0/19126.4.192.1 to 126.4.223.254126.4.223.2558,190
40126.4.224.0/19126.4.224.1 to 126.4.255.254126.4.255.2558,190
41126.5.0.0/19126.5.0.1 to 126.5.31.254126.5.31.2558,190
42126.5.32.0/19126.5.32.1 to 126.5.63.254126.5.63.2558,190
43126.5.64.0/19126.5.64.1 to 126.5.95.254126.5.95.2558,190
44126.5.96.0/19126.5.96.1 to 126.5.127.254126.5.127.2558,190
45126.5.128.0/19126.5.128.1 to 126.5.159.254126.5.159.2558,190
46126.5.160.0/19126.5.160.1 to 126.5.191.254126.5.191.2558,190
47126.5.192.0/19126.5.192.1 to 126.5.223.254126.5.223.2558,190
48126.5.224.0/19126.5.224.1 to 126.5.255.254126.5.255.2558,190
49126.6.0.0/19126.6.0.1 to 126.6.31.254126.6.31.2558,190
50126.6.32.0/19126.6.32.1 to 126.6.63.254126.6.63.2558,190
51126.6.64.0/19126.6.64.1 to 126.6.95.254126.6.95.2558,190
52126.6.96.0/19126.6.96.1 to 126.6.127.254126.6.127.2558,190
53126.6.128.0/19126.6.128.1 to 126.6.159.254126.6.159.2558,190
54126.6.160.0/19126.6.160.1 to 126.6.191.254126.6.191.2558,190
55126.6.192.0/19126.6.192.1 to 126.6.223.254126.6.223.2558,190
56126.6.224.0/19126.6.224.1 to 126.6.255.254126.6.255.2558,190
57126.7.0.0/19126.7.0.1 to 126.7.31.254126.7.31.2558,190
58126.7.32.0/19126.7.32.1 to 126.7.63.254126.7.63.2558,190
59126.7.64.0/19126.7.64.1 to 126.7.95.254126.7.95.2558,190
60126.7.96.0/19126.7.96.1 to 126.7.127.254126.7.127.2558,190
61126.7.128.0/19126.7.128.1 to 126.7.159.254126.7.159.2558,190
62126.7.160.0/19126.7.160.1 to 126.7.191.254126.7.191.2558,190
63126.7.192.0/19126.7.192.1 to 126.7.223.254126.7.223.2558,190
64126.7.224.0/19126.7.224.1 to 126.7.255.254126.7.255.2558,190
65126.8.0.0/19126.8.0.1 to 126.8.31.254126.8.31.2558,190
66126.8.32.0/19126.8.32.1 to 126.8.63.254126.8.63.2558,190
67126.8.64.0/19126.8.64.1 to 126.8.95.254126.8.95.2558,190
68126.8.96.0/19126.8.96.1 to 126.8.127.254126.8.127.2558,190
69126.8.128.0/19126.8.128.1 to 126.8.159.254126.8.159.2558,190
70126.8.160.0/19126.8.160.1 to 126.8.191.254126.8.191.2558,190
71126.8.192.0/19126.8.192.1 to 126.8.223.254126.8.223.2558,190
72126.8.224.0/19126.8.224.1 to 126.8.255.254126.8.255.2558,190
73126.9.0.0/19126.9.0.1 to 126.9.31.254126.9.31.2558,190
74126.9.32.0/19126.9.32.1 to 126.9.63.254126.9.63.2558,190
75126.9.64.0/19126.9.64.1 to 126.9.95.254126.9.95.2558,190
76126.9.96.0/19126.9.96.1 to 126.9.127.254126.9.127.2558,190
77126.9.128.0/19126.9.128.1 to 126.9.159.254126.9.159.2558,190
78126.9.160.0/19126.9.160.1 to 126.9.191.254126.9.191.2558,190
79126.9.192.0/19126.9.192.1 to 126.9.223.254126.9.223.2558,190
80126.9.224.0/19126.9.224.1 to 126.9.255.254126.9.255.2558,190
81126.10.0.0/19126.10.0.1 to 126.10.31.254126.10.31.2558,190
82126.10.32.0/19126.10.32.1 to 126.10.63.254126.10.63.2558,190
83126.10.64.0/19126.10.64.1 to 126.10.95.254126.10.95.2558,190
84126.10.96.0/19126.10.96.1 to 126.10.127.254126.10.127.2558,190
85126.10.128.0/19126.10.128.1 to 126.10.159.254126.10.159.2558,190
86126.10.160.0/19126.10.160.1 to 126.10.191.254126.10.191.2558,190
87126.10.192.0/19126.10.192.1 to 126.10.223.254126.10.223.2558,190
88126.10.224.0/19126.10.224.1 to 126.10.255.254126.10.255.2558,190
89126.11.0.0/19126.11.0.1 to 126.11.31.254126.11.31.2558,190
90126.11.32.0/19126.11.32.1 to 126.11.63.254126.11.63.2558,190
91126.11.64.0/19126.11.64.1 to 126.11.95.254126.11.95.2558,190
92126.11.96.0/19126.11.96.1 to 126.11.127.254126.11.127.2558,190
93126.11.128.0/19126.11.128.1 to 126.11.159.254126.11.159.2558,190
94126.11.160.0/19126.11.160.1 to 126.11.191.254126.11.191.2558,190
95126.11.192.0/19126.11.192.1 to 126.11.223.254126.11.223.2558,190
96126.11.224.0/19126.11.224.1 to 126.11.255.254126.11.255.2558,190
97126.12.0.0/19126.12.0.1 to 126.12.31.254126.12.31.2558,190
98126.12.32.0/19126.12.32.1 to 126.12.63.254126.12.63.2558,190
99126.12.64.0/19126.12.64.1 to 126.12.95.254126.12.95.2558,190
100126.12.96.0/19126.12.96.1 to 126.12.127.254126.12.127.2558,190
101126.12.128.0/19126.12.128.1 to 126.12.159.254126.12.159.2558,190
102126.12.160.0/19126.12.160.1 to 126.12.191.254126.12.191.2558,190
103126.12.192.0/19126.12.192.1 to 126.12.223.254126.12.223.2558,190
104126.12.224.0/19126.12.224.1 to 126.12.255.254126.12.255.2558,190
105126.13.0.0/19126.13.0.1 to 126.13.31.254126.13.31.2558,190
106126.13.32.0/19126.13.32.1 to 126.13.63.254126.13.63.2558,190
107126.13.64.0/19126.13.64.1 to 126.13.95.254126.13.95.2558,190
108126.13.96.0/19126.13.96.1 to 126.13.127.254126.13.127.2558,190
109126.13.128.0/19126.13.128.1 to 126.13.159.254126.13.159.2558,190
110126.13.160.0/19126.13.160.1 to 126.13.191.254126.13.191.2558,190
111126.13.192.0/19126.13.192.1 to 126.13.223.254126.13.223.2558,190
112126.13.224.0/19126.13.224.1 to 126.13.255.254126.13.255.2558,190
113126.14.0.0/19126.14.0.1 to 126.14.31.254126.14.31.2558,190
114126.14.32.0/19126.14.32.1 to 126.14.63.254126.14.63.2558,190
115126.14.64.0/19126.14.64.1 to 126.14.95.254126.14.95.2558,190
116126.14.96.0/19126.14.96.1 to 126.14.127.254126.14.127.2558,190
117126.14.128.0/19126.14.128.1 to 126.14.159.254126.14.159.2558,190
118126.14.160.0/19126.14.160.1 to 126.14.191.254126.14.191.2558,190
119126.14.192.0/19126.14.192.1 to 126.14.223.254126.14.223.2558,190
120126.14.224.0/19126.14.224.1 to 126.14.255.254126.14.255.2558,190
121126.15.0.0/19126.15.0.1 to 126.15.31.254126.15.31.2558,190
122126.15.32.0/19126.15.32.1 to 126.15.63.254126.15.63.2558,190
123126.15.64.0/19126.15.64.1 to 126.15.95.254126.15.95.2558,190
124126.15.96.0/19126.15.96.1 to 126.15.127.254126.15.127.2558,190
125126.15.128.0/19126.15.128.1 to 126.15.159.254126.15.159.2558,190
126126.15.160.0/19126.15.160.1 to 126.15.191.254126.15.191.2558,190
127126.15.192.0/19126.15.192.1 to 126.15.223.254126.15.223.2558,190
128126.15.224.0/19126.15.224.1 to 126.15.255.254126.15.255.2558,190
129126.16.0.0/19126.16.0.1 to 126.16.31.254126.16.31.2558,190
130126.16.32.0/19126.16.32.1 to 126.16.63.254126.16.63.2558,190
131126.16.64.0/19126.16.64.1 to 126.16.95.254126.16.95.2558,190
132126.16.96.0/19126.16.96.1 to 126.16.127.254126.16.127.2558,190
133126.16.128.0/19126.16.128.1 to 126.16.159.254126.16.159.2558,190
134126.16.160.0/19126.16.160.1 to 126.16.191.254126.16.191.2558,190
135126.16.192.0/19126.16.192.1 to 126.16.223.254126.16.223.2558,190
136126.16.224.0/19126.16.224.1 to 126.16.255.254126.16.255.2558,190
137126.17.0.0/19126.17.0.1 to 126.17.31.254126.17.31.2558,190
138126.17.32.0/19126.17.32.1 to 126.17.63.254126.17.63.2558,190
139126.17.64.0/19126.17.64.1 to 126.17.95.254126.17.95.2558,190
140126.17.96.0/19126.17.96.1 to 126.17.127.254126.17.127.2558,190
141126.17.128.0/19126.17.128.1 to 126.17.159.254126.17.159.2558,190
142126.17.160.0/19126.17.160.1 to 126.17.191.254126.17.191.2558,190
143126.17.192.0/19126.17.192.1 to 126.17.223.254126.17.223.2558,190
144126.17.224.0/19126.17.224.1 to 126.17.255.254126.17.255.2558,190
145126.18.0.0/19126.18.0.1 to 126.18.31.254126.18.31.2558,190
146126.18.32.0/19126.18.32.1 to 126.18.63.254126.18.63.2558,190
147126.18.64.0/19126.18.64.1 to 126.18.95.254126.18.95.2558,190
148126.18.96.0/19126.18.96.1 to 126.18.127.254126.18.127.2558,190
149126.18.128.0/19126.18.128.1 to 126.18.159.254126.18.159.2558,190
150126.18.160.0/19126.18.160.1 to 126.18.191.254126.18.191.2558,190
151126.18.192.0/19126.18.192.1 to 126.18.223.254126.18.223.2558,190
152126.18.224.0/19126.18.224.1 to 126.18.255.254126.18.255.2558,190
153126.19.0.0/19126.19.0.1 to 126.19.31.254126.19.31.2558,190
154126.19.32.0/19126.19.32.1 to 126.19.63.254126.19.63.2558,190
155126.19.64.0/19126.19.64.1 to 126.19.95.254126.19.95.2558,190
156126.19.96.0/19126.19.96.1 to 126.19.127.254126.19.127.2558,190
157126.19.128.0/19126.19.128.1 to 126.19.159.254126.19.159.2558,190
158126.19.160.0/19126.19.160.1 to 126.19.191.254126.19.191.2558,190
159126.19.192.0/19126.19.192.1 to 126.19.223.254126.19.223.2558,190
160126.19.224.0/19126.19.224.1 to 126.19.255.254126.19.255.2558,190
161126.20.0.0/19126.20.0.1 to 126.20.31.254126.20.31.2558,190
162126.20.32.0/19126.20.32.1 to 126.20.63.254126.20.63.2558,190
163126.20.64.0/19126.20.64.1 to 126.20.95.254126.20.95.2558,190
164126.20.96.0/19126.20.96.1 to 126.20.127.254126.20.127.2558,190
165126.20.128.0/19126.20.128.1 to 126.20.159.254126.20.159.2558,190
166126.20.160.0/19126.20.160.1 to 126.20.191.254126.20.191.2558,190
167126.20.192.0/19126.20.192.1 to 126.20.223.254126.20.223.2558,190
168126.20.224.0/19126.20.224.1 to 126.20.255.254126.20.255.2558,190
169126.21.0.0/19126.21.0.1 to 126.21.31.254126.21.31.2558,190
170126.21.32.0/19126.21.32.1 to 126.21.63.254126.21.63.2558,190
171126.21.64.0/19126.21.64.1 to 126.21.95.254126.21.95.2558,190
172126.21.96.0/19126.21.96.1 to 126.21.127.254126.21.127.2558,190
173126.21.128.0/19126.21.128.1 to 126.21.159.254126.21.159.2558,190
174126.21.160.0/19126.21.160.1 to 126.21.191.254126.21.191.2558,190
175126.21.192.0/19126.21.192.1 to 126.21.223.254126.21.223.2558,190
176126.21.224.0/19126.21.224.1 to 126.21.255.254126.21.255.2558,190
177126.22.0.0/19126.22.0.1 to 126.22.31.254126.22.31.2558,190
178126.22.32.0/19126.22.32.1 to 126.22.63.254126.22.63.2558,190
179126.22.64.0/19126.22.64.1 to 126.22.95.254126.22.95.2558,190
180126.22.96.0/19126.22.96.1 to 126.22.127.254126.22.127.2558,190
181126.22.128.0/19126.22.128.1 to 126.22.159.254126.22.159.2558,190
182126.22.160.0/19126.22.160.1 to 126.22.191.254126.22.191.2558,190
183126.22.192.0/19126.22.192.1 to 126.22.223.254126.22.223.2558,190
184126.22.224.0/19126.22.224.1 to 126.22.255.254126.22.255.2558,190
185126.23.0.0/19126.23.0.1 to 126.23.31.254126.23.31.2558,190
186126.23.32.0/19126.23.32.1 to 126.23.63.254126.23.63.2558,190
187126.23.64.0/19126.23.64.1 to 126.23.95.254126.23.95.2558,190
188126.23.96.0/19126.23.96.1 to 126.23.127.254126.23.127.2558,190
189126.23.128.0/19126.23.128.1 to 126.23.159.254126.23.159.2558,190
190126.23.160.0/19126.23.160.1 to 126.23.191.254126.23.191.2558,190
191126.23.192.0/19126.23.192.1 to 126.23.223.254126.23.223.2558,190
192126.23.224.0/19126.23.224.1 to 126.23.255.254126.23.255.2558,190
193126.24.0.0/19126.24.0.1 to 126.24.31.254126.24.31.2558,190
194126.24.32.0/19126.24.32.1 to 126.24.63.254126.24.63.2558,190
195126.24.64.0/19126.24.64.1 to 126.24.95.254126.24.95.2558,190
196126.24.96.0/19126.24.96.1 to 126.24.127.254126.24.127.2558,190
197126.24.128.0/19126.24.128.1 to 126.24.159.254126.24.159.2558,190
198126.24.160.0/19126.24.160.1 to 126.24.191.254126.24.191.2558,190
199126.24.192.0/19126.24.192.1 to 126.24.223.254126.24.223.2558,190
200126.24.224.0/19126.24.224.1 to 126.24.255.254126.24.255.2558,190
201126.25.0.0/19126.25.0.1 to 126.25.31.254126.25.31.2558,190
202126.25.32.0/19126.25.32.1 to 126.25.63.254126.25.63.2558,190
203126.25.64.0/19126.25.64.1 to 126.25.95.254126.25.95.2558,190
204126.25.96.0/19126.25.96.1 to 126.25.127.254126.25.127.2558,190
205126.25.128.0/19126.25.128.1 to 126.25.159.254126.25.159.2558,190
206126.25.160.0/19126.25.160.1 to 126.25.191.254126.25.191.2558,190
207126.25.192.0/19126.25.192.1 to 126.25.223.254126.25.223.2558,190
208126.25.224.0/19126.25.224.1 to 126.25.255.254126.25.255.2558,190
209126.26.0.0/19126.26.0.1 to 126.26.31.254126.26.31.2558,190
210126.26.32.0/19126.26.32.1 to 126.26.63.254126.26.63.2558,190
211126.26.64.0/19126.26.64.1 to 126.26.95.254126.26.95.2558,190
212126.26.96.0/19126.26.96.1 to 126.26.127.254126.26.127.2558,190
213126.26.128.0/19126.26.128.1 to 126.26.159.254126.26.159.2558,190
214126.26.160.0/19126.26.160.1 to 126.26.191.254126.26.191.2558,190
215126.26.192.0/19126.26.192.1 to 126.26.223.254126.26.223.2558,190
216126.26.224.0/19126.26.224.1 to 126.26.255.254126.26.255.2558,190
217126.27.0.0/19126.27.0.1 to 126.27.31.254126.27.31.2558,190
218126.27.32.0/19126.27.32.1 to 126.27.63.254126.27.63.2558,190
219126.27.64.0/19126.27.64.1 to 126.27.95.254126.27.95.2558,190
220126.27.96.0/19126.27.96.1 to 126.27.127.254126.27.127.2558,190
221126.27.128.0/19126.27.128.1 to 126.27.159.254126.27.159.2558,190
222126.27.160.0/19126.27.160.1 to 126.27.191.254126.27.191.2558,190
223126.27.192.0/19126.27.192.1 to 126.27.223.254126.27.223.2558,190
224126.27.224.0/19126.27.224.1 to 126.27.255.254126.27.255.2558,190
225126.28.0.0/19126.28.0.1 to 126.28.31.254126.28.31.2558,190
226126.28.32.0/19126.28.32.1 to 126.28.63.254126.28.63.2558,190
227126.28.64.0/19126.28.64.1 to 126.28.95.254126.28.95.2558,190
228126.28.96.0/19126.28.96.1 to 126.28.127.254126.28.127.2558,190
229126.28.128.0/19126.28.128.1 to 126.28.159.254126.28.159.2558,190
230126.28.160.0/19126.28.160.1 to 126.28.191.254126.28.191.2558,190
231126.28.192.0/19126.28.192.1 to 126.28.223.254126.28.223.2558,190
232126.28.224.0/19126.28.224.1 to 126.28.255.254126.28.255.2558,190
233126.29.0.0/19126.29.0.1 to 126.29.31.254126.29.31.2558,190
234126.29.32.0/19126.29.32.1 to 126.29.63.254126.29.63.2558,190
235126.29.64.0/19126.29.64.1 to 126.29.95.254126.29.95.2558,190
236126.29.96.0/19126.29.96.1 to 126.29.127.254126.29.127.2558,190
237126.29.128.0/19126.29.128.1 to 126.29.159.254126.29.159.2558,190
238126.29.160.0/19126.29.160.1 to 126.29.191.254126.29.191.2558,190
239126.29.192.0/19126.29.192.1 to 126.29.223.254126.29.223.2558,190
240126.29.224.0/19126.29.224.1 to 126.29.255.254126.29.255.2558,190
241126.30.0.0/19126.30.0.1 to 126.30.31.254126.30.31.2558,190
242126.30.32.0/19126.30.32.1 to 126.30.63.254126.30.63.2558,190
243126.30.64.0/19126.30.64.1 to 126.30.95.254126.30.95.2558,190
244126.30.96.0/19126.30.96.1 to 126.30.127.254126.30.127.2558,190
245126.30.128.0/19126.30.128.1 to 126.30.159.254126.30.159.2558,190
246126.30.160.0/19126.30.160.1 to 126.30.191.254126.30.191.2558,190
247126.30.192.0/19126.30.192.1 to 126.30.223.254126.30.223.2558,190
248126.30.224.0/19126.30.224.1 to 126.30.255.254126.30.255.2558,190
249126.31.0.0/19126.31.0.1 to 126.31.31.254126.31.31.2558,190
250126.31.32.0/19126.31.32.1 to 126.31.63.254126.31.63.2558,190
251126.31.64.0/19126.31.64.1 to 126.31.95.254126.31.95.2558,190
252126.31.96.0/19126.31.96.1 to 126.31.127.254126.31.127.2558,190
253126.31.128.0/19126.31.128.1 to 126.31.159.254126.31.159.2558,190
254126.31.160.0/19126.31.160.1 to 126.31.191.254126.31.191.2558,190
255126.31.192.0/19126.31.192.1 to 126.31.223.254126.31.223.2558,190
256126.31.224.0/19126.31.224.1 to 126.31.255.254126.31.255.2558,190

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.