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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.

Network126.232.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
126.232.0.0
Broadcast address
126.239.255.255
First usable
126.232.0.1
Last usable
126.239.255.254
Usable hosts
524,286 (524,288 less the network and broadcast addresses)
Subnet mask
255.248.0.0
Wildcard mask
0.7.255.255 (Cisco ACLs, OSPF)
Prefix length
/13
Type
Public public
Old class
A (default /8)
As numbers
Hex 7EE80000 · Integer 2129133568 to 2129657855
Reverse DNS zones
232.126.in-addr.arpa
233.126.in-addr.arpa
234.126.in-addr.arpa
235.126.in-addr.arpa
236.126.in-addr.arpa
237.126.in-addr.arpa
238.126.in-addr.arpa
239.126.in-addr.arpa
/13 is not on a 8-bit boundary, so it takes 8 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01111110.11101000.00000000.00000000126.232.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network01111110.11101000.00000000.00000000126.232.0.0
Broadcast01111110.11101111.11111111.11111111126.239.255.255
Split into smaller subnets/21
/14 (2)/15 (4)/16 (8)/17 (16)/18 (32)/19 (64)/20 (128)/21 (256)/22 (512)/23 (1,024)/24 (2,048)/25 (4,096)

126.232.0.0/13 makes 256 subnets of /21.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1126.232.0.0/21126.232.0.1 to 126.232.7.254126.232.7.2552,046
2126.232.8.0/21126.232.8.1 to 126.232.15.254126.232.15.2552,046
3126.232.16.0/21126.232.16.1 to 126.232.23.254126.232.23.2552,046
4126.232.24.0/21126.232.24.1 to 126.232.31.254126.232.31.2552,046
5126.232.32.0/21126.232.32.1 to 126.232.39.254126.232.39.2552,046
6126.232.40.0/21126.232.40.1 to 126.232.47.254126.232.47.2552,046
7126.232.48.0/21126.232.48.1 to 126.232.55.254126.232.55.2552,046
8126.232.56.0/21126.232.56.1 to 126.232.63.254126.232.63.2552,046
9126.232.64.0/21126.232.64.1 to 126.232.71.254126.232.71.2552,046
10126.232.72.0/21126.232.72.1 to 126.232.79.254126.232.79.2552,046
11126.232.80.0/21126.232.80.1 to 126.232.87.254126.232.87.2552,046
12126.232.88.0/21126.232.88.1 to 126.232.95.254126.232.95.2552,046
13126.232.96.0/21126.232.96.1 to 126.232.103.254126.232.103.2552,046
14126.232.104.0/21126.232.104.1 to 126.232.111.254126.232.111.2552,046
15126.232.112.0/21126.232.112.1 to 126.232.119.254126.232.119.2552,046
16126.232.120.0/21126.232.120.1 to 126.232.127.254126.232.127.2552,046
17126.232.128.0/21126.232.128.1 to 126.232.135.254126.232.135.2552,046
18126.232.136.0/21126.232.136.1 to 126.232.143.254126.232.143.2552,046
19126.232.144.0/21126.232.144.1 to 126.232.151.254126.232.151.2552,046
20126.232.152.0/21126.232.152.1 to 126.232.159.254126.232.159.2552,046
21126.232.160.0/21126.232.160.1 to 126.232.167.254126.232.167.2552,046
22126.232.168.0/21126.232.168.1 to 126.232.175.254126.232.175.2552,046
23126.232.176.0/21126.232.176.1 to 126.232.183.254126.232.183.2552,046
24126.232.184.0/21126.232.184.1 to 126.232.191.254126.232.191.2552,046
25126.232.192.0/21126.232.192.1 to 126.232.199.254126.232.199.2552,046
26126.232.200.0/21126.232.200.1 to 126.232.207.254126.232.207.2552,046
27126.232.208.0/21126.232.208.1 to 126.232.215.254126.232.215.2552,046
28126.232.216.0/21126.232.216.1 to 126.232.223.254126.232.223.2552,046
29126.232.224.0/21126.232.224.1 to 126.232.231.254126.232.231.2552,046
30126.232.232.0/21126.232.232.1 to 126.232.239.254126.232.239.2552,046
31126.232.240.0/21126.232.240.1 to 126.232.247.254126.232.247.2552,046
32126.232.248.0/21126.232.248.1 to 126.232.255.254126.232.255.2552,046
33126.233.0.0/21126.233.0.1 to 126.233.7.254126.233.7.2552,046
34126.233.8.0/21126.233.8.1 to 126.233.15.254126.233.15.2552,046
35126.233.16.0/21126.233.16.1 to 126.233.23.254126.233.23.2552,046
36126.233.24.0/21126.233.24.1 to 126.233.31.254126.233.31.2552,046
37126.233.32.0/21126.233.32.1 to 126.233.39.254126.233.39.2552,046
38126.233.40.0/21126.233.40.1 to 126.233.47.254126.233.47.2552,046
39126.233.48.0/21126.233.48.1 to 126.233.55.254126.233.55.2552,046
40126.233.56.0/21126.233.56.1 to 126.233.63.254126.233.63.2552,046
41126.233.64.0/21126.233.64.1 to 126.233.71.254126.233.71.2552,046
42126.233.72.0/21126.233.72.1 to 126.233.79.254126.233.79.2552,046
43126.233.80.0/21126.233.80.1 to 126.233.87.254126.233.87.2552,046
44126.233.88.0/21126.233.88.1 to 126.233.95.254126.233.95.2552,046
45126.233.96.0/21126.233.96.1 to 126.233.103.254126.233.103.2552,046
46126.233.104.0/21126.233.104.1 to 126.233.111.254126.233.111.2552,046
47126.233.112.0/21126.233.112.1 to 126.233.119.254126.233.119.2552,046
48126.233.120.0/21126.233.120.1 to 126.233.127.254126.233.127.2552,046
49126.233.128.0/21126.233.128.1 to 126.233.135.254126.233.135.2552,046
50126.233.136.0/21126.233.136.1 to 126.233.143.254126.233.143.2552,046
51126.233.144.0/21126.233.144.1 to 126.233.151.254126.233.151.2552,046
52126.233.152.0/21126.233.152.1 to 126.233.159.254126.233.159.2552,046
53126.233.160.0/21126.233.160.1 to 126.233.167.254126.233.167.2552,046
54126.233.168.0/21126.233.168.1 to 126.233.175.254126.233.175.2552,046
55126.233.176.0/21126.233.176.1 to 126.233.183.254126.233.183.2552,046
56126.233.184.0/21126.233.184.1 to 126.233.191.254126.233.191.2552,046
57126.233.192.0/21126.233.192.1 to 126.233.199.254126.233.199.2552,046
58126.233.200.0/21126.233.200.1 to 126.233.207.254126.233.207.2552,046
59126.233.208.0/21126.233.208.1 to 126.233.215.254126.233.215.2552,046
60126.233.216.0/21126.233.216.1 to 126.233.223.254126.233.223.2552,046
61126.233.224.0/21126.233.224.1 to 126.233.231.254126.233.231.2552,046
62126.233.232.0/21126.233.232.1 to 126.233.239.254126.233.239.2552,046
63126.233.240.0/21126.233.240.1 to 126.233.247.254126.233.247.2552,046
64126.233.248.0/21126.233.248.1 to 126.233.255.254126.233.255.2552,046
65126.234.0.0/21126.234.0.1 to 126.234.7.254126.234.7.2552,046
66126.234.8.0/21126.234.8.1 to 126.234.15.254126.234.15.2552,046
67126.234.16.0/21126.234.16.1 to 126.234.23.254126.234.23.2552,046
68126.234.24.0/21126.234.24.1 to 126.234.31.254126.234.31.2552,046
69126.234.32.0/21126.234.32.1 to 126.234.39.254126.234.39.2552,046
70126.234.40.0/21126.234.40.1 to 126.234.47.254126.234.47.2552,046
71126.234.48.0/21126.234.48.1 to 126.234.55.254126.234.55.2552,046
72126.234.56.0/21126.234.56.1 to 126.234.63.254126.234.63.2552,046
73126.234.64.0/21126.234.64.1 to 126.234.71.254126.234.71.2552,046
74126.234.72.0/21126.234.72.1 to 126.234.79.254126.234.79.2552,046
75126.234.80.0/21126.234.80.1 to 126.234.87.254126.234.87.2552,046
76126.234.88.0/21126.234.88.1 to 126.234.95.254126.234.95.2552,046
77126.234.96.0/21126.234.96.1 to 126.234.103.254126.234.103.2552,046
78126.234.104.0/21126.234.104.1 to 126.234.111.254126.234.111.2552,046
79126.234.112.0/21126.234.112.1 to 126.234.119.254126.234.119.2552,046
80126.234.120.0/21126.234.120.1 to 126.234.127.254126.234.127.2552,046
81126.234.128.0/21126.234.128.1 to 126.234.135.254126.234.135.2552,046
82126.234.136.0/21126.234.136.1 to 126.234.143.254126.234.143.2552,046
83126.234.144.0/21126.234.144.1 to 126.234.151.254126.234.151.2552,046
84126.234.152.0/21126.234.152.1 to 126.234.159.254126.234.159.2552,046
85126.234.160.0/21126.234.160.1 to 126.234.167.254126.234.167.2552,046
86126.234.168.0/21126.234.168.1 to 126.234.175.254126.234.175.2552,046
87126.234.176.0/21126.234.176.1 to 126.234.183.254126.234.183.2552,046
88126.234.184.0/21126.234.184.1 to 126.234.191.254126.234.191.2552,046
89126.234.192.0/21126.234.192.1 to 126.234.199.254126.234.199.2552,046
90126.234.200.0/21126.234.200.1 to 126.234.207.254126.234.207.2552,046
91126.234.208.0/21126.234.208.1 to 126.234.215.254126.234.215.2552,046
92126.234.216.0/21126.234.216.1 to 126.234.223.254126.234.223.2552,046
93126.234.224.0/21126.234.224.1 to 126.234.231.254126.234.231.2552,046
94126.234.232.0/21126.234.232.1 to 126.234.239.254126.234.239.2552,046
95126.234.240.0/21126.234.240.1 to 126.234.247.254126.234.247.2552,046
96126.234.248.0/21126.234.248.1 to 126.234.255.254126.234.255.2552,046
97126.235.0.0/21126.235.0.1 to 126.235.7.254126.235.7.2552,046
98126.235.8.0/21126.235.8.1 to 126.235.15.254126.235.15.2552,046
99126.235.16.0/21126.235.16.1 to 126.235.23.254126.235.23.2552,046
100126.235.24.0/21126.235.24.1 to 126.235.31.254126.235.31.2552,046
101126.235.32.0/21126.235.32.1 to 126.235.39.254126.235.39.2552,046
102126.235.40.0/21126.235.40.1 to 126.235.47.254126.235.47.2552,046
103126.235.48.0/21126.235.48.1 to 126.235.55.254126.235.55.2552,046
104126.235.56.0/21126.235.56.1 to 126.235.63.254126.235.63.2552,046
105126.235.64.0/21126.235.64.1 to 126.235.71.254126.235.71.2552,046
106126.235.72.0/21126.235.72.1 to 126.235.79.254126.235.79.2552,046
107126.235.80.0/21126.235.80.1 to 126.235.87.254126.235.87.2552,046
108126.235.88.0/21126.235.88.1 to 126.235.95.254126.235.95.2552,046
109126.235.96.0/21126.235.96.1 to 126.235.103.254126.235.103.2552,046
110126.235.104.0/21126.235.104.1 to 126.235.111.254126.235.111.2552,046
111126.235.112.0/21126.235.112.1 to 126.235.119.254126.235.119.2552,046
112126.235.120.0/21126.235.120.1 to 126.235.127.254126.235.127.2552,046
113126.235.128.0/21126.235.128.1 to 126.235.135.254126.235.135.2552,046
114126.235.136.0/21126.235.136.1 to 126.235.143.254126.235.143.2552,046
115126.235.144.0/21126.235.144.1 to 126.235.151.254126.235.151.2552,046
116126.235.152.0/21126.235.152.1 to 126.235.159.254126.235.159.2552,046
117126.235.160.0/21126.235.160.1 to 126.235.167.254126.235.167.2552,046
118126.235.168.0/21126.235.168.1 to 126.235.175.254126.235.175.2552,046
119126.235.176.0/21126.235.176.1 to 126.235.183.254126.235.183.2552,046
120126.235.184.0/21126.235.184.1 to 126.235.191.254126.235.191.2552,046
121126.235.192.0/21126.235.192.1 to 126.235.199.254126.235.199.2552,046
122126.235.200.0/21126.235.200.1 to 126.235.207.254126.235.207.2552,046
123126.235.208.0/21126.235.208.1 to 126.235.215.254126.235.215.2552,046
124126.235.216.0/21126.235.216.1 to 126.235.223.254126.235.223.2552,046
125126.235.224.0/21126.235.224.1 to 126.235.231.254126.235.231.2552,046
126126.235.232.0/21126.235.232.1 to 126.235.239.254126.235.239.2552,046
127126.235.240.0/21126.235.240.1 to 126.235.247.254126.235.247.2552,046
128126.235.248.0/21126.235.248.1 to 126.235.255.254126.235.255.2552,046
129126.236.0.0/21126.236.0.1 to 126.236.7.254126.236.7.2552,046
130126.236.8.0/21126.236.8.1 to 126.236.15.254126.236.15.2552,046
131126.236.16.0/21126.236.16.1 to 126.236.23.254126.236.23.2552,046
132126.236.24.0/21126.236.24.1 to 126.236.31.254126.236.31.2552,046
133126.236.32.0/21126.236.32.1 to 126.236.39.254126.236.39.2552,046
134126.236.40.0/21126.236.40.1 to 126.236.47.254126.236.47.2552,046
135126.236.48.0/21126.236.48.1 to 126.236.55.254126.236.55.2552,046
136126.236.56.0/21126.236.56.1 to 126.236.63.254126.236.63.2552,046
137126.236.64.0/21126.236.64.1 to 126.236.71.254126.236.71.2552,046
138126.236.72.0/21126.236.72.1 to 126.236.79.254126.236.79.2552,046
139126.236.80.0/21126.236.80.1 to 126.236.87.254126.236.87.2552,046
140126.236.88.0/21126.236.88.1 to 126.236.95.254126.236.95.2552,046
141126.236.96.0/21126.236.96.1 to 126.236.103.254126.236.103.2552,046
142126.236.104.0/21126.236.104.1 to 126.236.111.254126.236.111.2552,046
143126.236.112.0/21126.236.112.1 to 126.236.119.254126.236.119.2552,046
144126.236.120.0/21126.236.120.1 to 126.236.127.254126.236.127.2552,046
145126.236.128.0/21126.236.128.1 to 126.236.135.254126.236.135.2552,046
146126.236.136.0/21126.236.136.1 to 126.236.143.254126.236.143.2552,046
147126.236.144.0/21126.236.144.1 to 126.236.151.254126.236.151.2552,046
148126.236.152.0/21126.236.152.1 to 126.236.159.254126.236.159.2552,046
149126.236.160.0/21126.236.160.1 to 126.236.167.254126.236.167.2552,046
150126.236.168.0/21126.236.168.1 to 126.236.175.254126.236.175.2552,046
151126.236.176.0/21126.236.176.1 to 126.236.183.254126.236.183.2552,046
152126.236.184.0/21126.236.184.1 to 126.236.191.254126.236.191.2552,046
153126.236.192.0/21126.236.192.1 to 126.236.199.254126.236.199.2552,046
154126.236.200.0/21126.236.200.1 to 126.236.207.254126.236.207.2552,046
155126.236.208.0/21126.236.208.1 to 126.236.215.254126.236.215.2552,046
156126.236.216.0/21126.236.216.1 to 126.236.223.254126.236.223.2552,046
157126.236.224.0/21126.236.224.1 to 126.236.231.254126.236.231.2552,046
158126.236.232.0/21126.236.232.1 to 126.236.239.254126.236.239.2552,046
159126.236.240.0/21126.236.240.1 to 126.236.247.254126.236.247.2552,046
160126.236.248.0/21126.236.248.1 to 126.236.255.254126.236.255.2552,046
161126.237.0.0/21126.237.0.1 to 126.237.7.254126.237.7.2552,046
162126.237.8.0/21126.237.8.1 to 126.237.15.254126.237.15.2552,046
163126.237.16.0/21126.237.16.1 to 126.237.23.254126.237.23.2552,046
164126.237.24.0/21126.237.24.1 to 126.237.31.254126.237.31.2552,046
165126.237.32.0/21126.237.32.1 to 126.237.39.254126.237.39.2552,046
166126.237.40.0/21126.237.40.1 to 126.237.47.254126.237.47.2552,046
167126.237.48.0/21126.237.48.1 to 126.237.55.254126.237.55.2552,046
168126.237.56.0/21126.237.56.1 to 126.237.63.254126.237.63.2552,046
169126.237.64.0/21126.237.64.1 to 126.237.71.254126.237.71.2552,046
170126.237.72.0/21126.237.72.1 to 126.237.79.254126.237.79.2552,046
171126.237.80.0/21126.237.80.1 to 126.237.87.254126.237.87.2552,046
172126.237.88.0/21126.237.88.1 to 126.237.95.254126.237.95.2552,046
173126.237.96.0/21126.237.96.1 to 126.237.103.254126.237.103.2552,046
174126.237.104.0/21126.237.104.1 to 126.237.111.254126.237.111.2552,046
175126.237.112.0/21126.237.112.1 to 126.237.119.254126.237.119.2552,046
176126.237.120.0/21126.237.120.1 to 126.237.127.254126.237.127.2552,046
177126.237.128.0/21126.237.128.1 to 126.237.135.254126.237.135.2552,046
178126.237.136.0/21126.237.136.1 to 126.237.143.254126.237.143.2552,046
179126.237.144.0/21126.237.144.1 to 126.237.151.254126.237.151.2552,046
180126.237.152.0/21126.237.152.1 to 126.237.159.254126.237.159.2552,046
181126.237.160.0/21126.237.160.1 to 126.237.167.254126.237.167.2552,046
182126.237.168.0/21126.237.168.1 to 126.237.175.254126.237.175.2552,046
183126.237.176.0/21126.237.176.1 to 126.237.183.254126.237.183.2552,046
184126.237.184.0/21126.237.184.1 to 126.237.191.254126.237.191.2552,046
185126.237.192.0/21126.237.192.1 to 126.237.199.254126.237.199.2552,046
186126.237.200.0/21126.237.200.1 to 126.237.207.254126.237.207.2552,046
187126.237.208.0/21126.237.208.1 to 126.237.215.254126.237.215.2552,046
188126.237.216.0/21126.237.216.1 to 126.237.223.254126.237.223.2552,046
189126.237.224.0/21126.237.224.1 to 126.237.231.254126.237.231.2552,046
190126.237.232.0/21126.237.232.1 to 126.237.239.254126.237.239.2552,046
191126.237.240.0/21126.237.240.1 to 126.237.247.254126.237.247.2552,046
192126.237.248.0/21126.237.248.1 to 126.237.255.254126.237.255.2552,046
193126.238.0.0/21126.238.0.1 to 126.238.7.254126.238.7.2552,046
194126.238.8.0/21126.238.8.1 to 126.238.15.254126.238.15.2552,046
195126.238.16.0/21126.238.16.1 to 126.238.23.254126.238.23.2552,046
196126.238.24.0/21126.238.24.1 to 126.238.31.254126.238.31.2552,046
197126.238.32.0/21126.238.32.1 to 126.238.39.254126.238.39.2552,046
198126.238.40.0/21126.238.40.1 to 126.238.47.254126.238.47.2552,046
199126.238.48.0/21126.238.48.1 to 126.238.55.254126.238.55.2552,046
200126.238.56.0/21126.238.56.1 to 126.238.63.254126.238.63.2552,046
201126.238.64.0/21126.238.64.1 to 126.238.71.254126.238.71.2552,046
202126.238.72.0/21126.238.72.1 to 126.238.79.254126.238.79.2552,046
203126.238.80.0/21126.238.80.1 to 126.238.87.254126.238.87.2552,046
204126.238.88.0/21126.238.88.1 to 126.238.95.254126.238.95.2552,046
205126.238.96.0/21126.238.96.1 to 126.238.103.254126.238.103.2552,046
206126.238.104.0/21126.238.104.1 to 126.238.111.254126.238.111.2552,046
207126.238.112.0/21126.238.112.1 to 126.238.119.254126.238.119.2552,046
208126.238.120.0/21126.238.120.1 to 126.238.127.254126.238.127.2552,046
209126.238.128.0/21126.238.128.1 to 126.238.135.254126.238.135.2552,046
210126.238.136.0/21126.238.136.1 to 126.238.143.254126.238.143.2552,046
211126.238.144.0/21126.238.144.1 to 126.238.151.254126.238.151.2552,046
212126.238.152.0/21126.238.152.1 to 126.238.159.254126.238.159.2552,046
213126.238.160.0/21126.238.160.1 to 126.238.167.254126.238.167.2552,046
214126.238.168.0/21126.238.168.1 to 126.238.175.254126.238.175.2552,046
215126.238.176.0/21126.238.176.1 to 126.238.183.254126.238.183.2552,046
216126.238.184.0/21126.238.184.1 to 126.238.191.254126.238.191.2552,046
217126.238.192.0/21126.238.192.1 to 126.238.199.254126.238.199.2552,046
218126.238.200.0/21126.238.200.1 to 126.238.207.254126.238.207.2552,046
219126.238.208.0/21126.238.208.1 to 126.238.215.254126.238.215.2552,046
220126.238.216.0/21126.238.216.1 to 126.238.223.254126.238.223.2552,046
221126.238.224.0/21126.238.224.1 to 126.238.231.254126.238.231.2552,046
222126.238.232.0/21126.238.232.1 to 126.238.239.254126.238.239.2552,046
223126.238.240.0/21126.238.240.1 to 126.238.247.254126.238.247.2552,046
224126.238.248.0/21126.238.248.1 to 126.238.255.254126.238.255.2552,046
225126.239.0.0/21126.239.0.1 to 126.239.7.254126.239.7.2552,046
226126.239.8.0/21126.239.8.1 to 126.239.15.254126.239.15.2552,046
227126.239.16.0/21126.239.16.1 to 126.239.23.254126.239.23.2552,046
228126.239.24.0/21126.239.24.1 to 126.239.31.254126.239.31.2552,046
229126.239.32.0/21126.239.32.1 to 126.239.39.254126.239.39.2552,046
230126.239.40.0/21126.239.40.1 to 126.239.47.254126.239.47.2552,046
231126.239.48.0/21126.239.48.1 to 126.239.55.254126.239.55.2552,046
232126.239.56.0/21126.239.56.1 to 126.239.63.254126.239.63.2552,046
233126.239.64.0/21126.239.64.1 to 126.239.71.254126.239.71.2552,046
234126.239.72.0/21126.239.72.1 to 126.239.79.254126.239.79.2552,046
235126.239.80.0/21126.239.80.1 to 126.239.87.254126.239.87.2552,046
236126.239.88.0/21126.239.88.1 to 126.239.95.254126.239.95.2552,046
237126.239.96.0/21126.239.96.1 to 126.239.103.254126.239.103.2552,046
238126.239.104.0/21126.239.104.1 to 126.239.111.254126.239.111.2552,046
239126.239.112.0/21126.239.112.1 to 126.239.119.254126.239.119.2552,046
240126.239.120.0/21126.239.120.1 to 126.239.127.254126.239.127.2552,046
241126.239.128.0/21126.239.128.1 to 126.239.135.254126.239.135.2552,046
242126.239.136.0/21126.239.136.1 to 126.239.143.254126.239.143.2552,046
243126.239.144.0/21126.239.144.1 to 126.239.151.254126.239.151.2552,046
244126.239.152.0/21126.239.152.1 to 126.239.159.254126.239.159.2552,046
245126.239.160.0/21126.239.160.1 to 126.239.167.254126.239.167.2552,046
246126.239.168.0/21126.239.168.1 to 126.239.175.254126.239.175.2552,046
247126.239.176.0/21126.239.176.1 to 126.239.183.254126.239.183.2552,046
248126.239.184.0/21126.239.184.1 to 126.239.191.254126.239.191.2552,046
249126.239.192.0/21126.239.192.1 to 126.239.199.254126.239.199.2552,046
250126.239.200.0/21126.239.200.1 to 126.239.207.254126.239.207.2552,046
251126.239.208.0/21126.239.208.1 to 126.239.215.254126.239.215.2552,046
252126.239.216.0/21126.239.216.1 to 126.239.223.254126.239.223.2552,046
253126.239.224.0/21126.239.224.1 to 126.239.231.254126.239.231.2552,046
254126.239.232.0/21126.239.232.1 to 126.239.239.254126.239.239.2552,046
255126.239.240.0/21126.239.240.1 to 126.239.247.254126.239.247.2552,046
256126.239.248.0/21126.239.248.1 to 126.239.255.254126.239.255.2552,046

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.