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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/16
/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 256 subnets of /16.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1126.0.0.0/16126.0.0.1 to 126.0.255.254126.0.255.25565,534
2126.1.0.0/16126.1.0.1 to 126.1.255.254126.1.255.25565,534
3126.2.0.0/16126.2.0.1 to 126.2.255.254126.2.255.25565,534
4126.3.0.0/16126.3.0.1 to 126.3.255.254126.3.255.25565,534
5126.4.0.0/16126.4.0.1 to 126.4.255.254126.4.255.25565,534
6126.5.0.0/16126.5.0.1 to 126.5.255.254126.5.255.25565,534
7126.6.0.0/16126.6.0.1 to 126.6.255.254126.6.255.25565,534
8126.7.0.0/16126.7.0.1 to 126.7.255.254126.7.255.25565,534
9126.8.0.0/16126.8.0.1 to 126.8.255.254126.8.255.25565,534
10126.9.0.0/16126.9.0.1 to 126.9.255.254126.9.255.25565,534
11126.10.0.0/16126.10.0.1 to 126.10.255.254126.10.255.25565,534
12126.11.0.0/16126.11.0.1 to 126.11.255.254126.11.255.25565,534
13126.12.0.0/16126.12.0.1 to 126.12.255.254126.12.255.25565,534
14126.13.0.0/16126.13.0.1 to 126.13.255.254126.13.255.25565,534
15126.14.0.0/16126.14.0.1 to 126.14.255.254126.14.255.25565,534
16126.15.0.0/16126.15.0.1 to 126.15.255.254126.15.255.25565,534
17126.16.0.0/16126.16.0.1 to 126.16.255.254126.16.255.25565,534
18126.17.0.0/16126.17.0.1 to 126.17.255.254126.17.255.25565,534
19126.18.0.0/16126.18.0.1 to 126.18.255.254126.18.255.25565,534
20126.19.0.0/16126.19.0.1 to 126.19.255.254126.19.255.25565,534
21126.20.0.0/16126.20.0.1 to 126.20.255.254126.20.255.25565,534
22126.21.0.0/16126.21.0.1 to 126.21.255.254126.21.255.25565,534
23126.22.0.0/16126.22.0.1 to 126.22.255.254126.22.255.25565,534
24126.23.0.0/16126.23.0.1 to 126.23.255.254126.23.255.25565,534
25126.24.0.0/16126.24.0.1 to 126.24.255.254126.24.255.25565,534
26126.25.0.0/16126.25.0.1 to 126.25.255.254126.25.255.25565,534
27126.26.0.0/16126.26.0.1 to 126.26.255.254126.26.255.25565,534
28126.27.0.0/16126.27.0.1 to 126.27.255.254126.27.255.25565,534
29126.28.0.0/16126.28.0.1 to 126.28.255.254126.28.255.25565,534
30126.29.0.0/16126.29.0.1 to 126.29.255.254126.29.255.25565,534
31126.30.0.0/16126.30.0.1 to 126.30.255.254126.30.255.25565,534
32126.31.0.0/16126.31.0.1 to 126.31.255.254126.31.255.25565,534
33126.32.0.0/16126.32.0.1 to 126.32.255.254126.32.255.25565,534
34126.33.0.0/16126.33.0.1 to 126.33.255.254126.33.255.25565,534
35126.34.0.0/16126.34.0.1 to 126.34.255.254126.34.255.25565,534
36126.35.0.0/16126.35.0.1 to 126.35.255.254126.35.255.25565,534
37126.36.0.0/16126.36.0.1 to 126.36.255.254126.36.255.25565,534
38126.37.0.0/16126.37.0.1 to 126.37.255.254126.37.255.25565,534
39126.38.0.0/16126.38.0.1 to 126.38.255.254126.38.255.25565,534
40126.39.0.0/16126.39.0.1 to 126.39.255.254126.39.255.25565,534
41126.40.0.0/16126.40.0.1 to 126.40.255.254126.40.255.25565,534
42126.41.0.0/16126.41.0.1 to 126.41.255.254126.41.255.25565,534
43126.42.0.0/16126.42.0.1 to 126.42.255.254126.42.255.25565,534
44126.43.0.0/16126.43.0.1 to 126.43.255.254126.43.255.25565,534
45126.44.0.0/16126.44.0.1 to 126.44.255.254126.44.255.25565,534
46126.45.0.0/16126.45.0.1 to 126.45.255.254126.45.255.25565,534
47126.46.0.0/16126.46.0.1 to 126.46.255.254126.46.255.25565,534
48126.47.0.0/16126.47.0.1 to 126.47.255.254126.47.255.25565,534
49126.48.0.0/16126.48.0.1 to 126.48.255.254126.48.255.25565,534
50126.49.0.0/16126.49.0.1 to 126.49.255.254126.49.255.25565,534
51126.50.0.0/16126.50.0.1 to 126.50.255.254126.50.255.25565,534
52126.51.0.0/16126.51.0.1 to 126.51.255.254126.51.255.25565,534
53126.52.0.0/16126.52.0.1 to 126.52.255.254126.52.255.25565,534
54126.53.0.0/16126.53.0.1 to 126.53.255.254126.53.255.25565,534
55126.54.0.0/16126.54.0.1 to 126.54.255.254126.54.255.25565,534
56126.55.0.0/16126.55.0.1 to 126.55.255.254126.55.255.25565,534
57126.56.0.0/16126.56.0.1 to 126.56.255.254126.56.255.25565,534
58126.57.0.0/16126.57.0.1 to 126.57.255.254126.57.255.25565,534
59126.58.0.0/16126.58.0.1 to 126.58.255.254126.58.255.25565,534
60126.59.0.0/16126.59.0.1 to 126.59.255.254126.59.255.25565,534
61126.60.0.0/16126.60.0.1 to 126.60.255.254126.60.255.25565,534
62126.61.0.0/16126.61.0.1 to 126.61.255.254126.61.255.25565,534
63126.62.0.0/16126.62.0.1 to 126.62.255.254126.62.255.25565,534
64126.63.0.0/16126.63.0.1 to 126.63.255.254126.63.255.25565,534
65126.64.0.0/16126.64.0.1 to 126.64.255.254126.64.255.25565,534
66126.65.0.0/16126.65.0.1 to 126.65.255.254126.65.255.25565,534
67126.66.0.0/16126.66.0.1 to 126.66.255.254126.66.255.25565,534
68126.67.0.0/16126.67.0.1 to 126.67.255.254126.67.255.25565,534
69126.68.0.0/16126.68.0.1 to 126.68.255.254126.68.255.25565,534
70126.69.0.0/16126.69.0.1 to 126.69.255.254126.69.255.25565,534
71126.70.0.0/16126.70.0.1 to 126.70.255.254126.70.255.25565,534
72126.71.0.0/16126.71.0.1 to 126.71.255.254126.71.255.25565,534
73126.72.0.0/16126.72.0.1 to 126.72.255.254126.72.255.25565,534
74126.73.0.0/16126.73.0.1 to 126.73.255.254126.73.255.25565,534
75126.74.0.0/16126.74.0.1 to 126.74.255.254126.74.255.25565,534
76126.75.0.0/16126.75.0.1 to 126.75.255.254126.75.255.25565,534
77126.76.0.0/16126.76.0.1 to 126.76.255.254126.76.255.25565,534
78126.77.0.0/16126.77.0.1 to 126.77.255.254126.77.255.25565,534
79126.78.0.0/16126.78.0.1 to 126.78.255.254126.78.255.25565,534
80126.79.0.0/16126.79.0.1 to 126.79.255.254126.79.255.25565,534
81126.80.0.0/16126.80.0.1 to 126.80.255.254126.80.255.25565,534
82126.81.0.0/16126.81.0.1 to 126.81.255.254126.81.255.25565,534
83126.82.0.0/16126.82.0.1 to 126.82.255.254126.82.255.25565,534
84126.83.0.0/16126.83.0.1 to 126.83.255.254126.83.255.25565,534
85126.84.0.0/16126.84.0.1 to 126.84.255.254126.84.255.25565,534
86126.85.0.0/16126.85.0.1 to 126.85.255.254126.85.255.25565,534
87126.86.0.0/16126.86.0.1 to 126.86.255.254126.86.255.25565,534
88126.87.0.0/16126.87.0.1 to 126.87.255.254126.87.255.25565,534
89126.88.0.0/16126.88.0.1 to 126.88.255.254126.88.255.25565,534
90126.89.0.0/16126.89.0.1 to 126.89.255.254126.89.255.25565,534
91126.90.0.0/16126.90.0.1 to 126.90.255.254126.90.255.25565,534
92126.91.0.0/16126.91.0.1 to 126.91.255.254126.91.255.25565,534
93126.92.0.0/16126.92.0.1 to 126.92.255.254126.92.255.25565,534
94126.93.0.0/16126.93.0.1 to 126.93.255.254126.93.255.25565,534
95126.94.0.0/16126.94.0.1 to 126.94.255.254126.94.255.25565,534
96126.95.0.0/16126.95.0.1 to 126.95.255.254126.95.255.25565,534
97126.96.0.0/16126.96.0.1 to 126.96.255.254126.96.255.25565,534
98126.97.0.0/16126.97.0.1 to 126.97.255.254126.97.255.25565,534
99126.98.0.0/16126.98.0.1 to 126.98.255.254126.98.255.25565,534
100126.99.0.0/16126.99.0.1 to 126.99.255.254126.99.255.25565,534
101126.100.0.0/16126.100.0.1 to 126.100.255.254126.100.255.25565,534
102126.101.0.0/16126.101.0.1 to 126.101.255.254126.101.255.25565,534
103126.102.0.0/16126.102.0.1 to 126.102.255.254126.102.255.25565,534
104126.103.0.0/16126.103.0.1 to 126.103.255.254126.103.255.25565,534
105126.104.0.0/16126.104.0.1 to 126.104.255.254126.104.255.25565,534
106126.105.0.0/16126.105.0.1 to 126.105.255.254126.105.255.25565,534
107126.106.0.0/16126.106.0.1 to 126.106.255.254126.106.255.25565,534
108126.107.0.0/16126.107.0.1 to 126.107.255.254126.107.255.25565,534
109126.108.0.0/16126.108.0.1 to 126.108.255.254126.108.255.25565,534
110126.109.0.0/16126.109.0.1 to 126.109.255.254126.109.255.25565,534
111126.110.0.0/16126.110.0.1 to 126.110.255.254126.110.255.25565,534
112126.111.0.0/16126.111.0.1 to 126.111.255.254126.111.255.25565,534
113126.112.0.0/16126.112.0.1 to 126.112.255.254126.112.255.25565,534
114126.113.0.0/16126.113.0.1 to 126.113.255.254126.113.255.25565,534
115126.114.0.0/16126.114.0.1 to 126.114.255.254126.114.255.25565,534
116126.115.0.0/16126.115.0.1 to 126.115.255.254126.115.255.25565,534
117126.116.0.0/16126.116.0.1 to 126.116.255.254126.116.255.25565,534
118126.117.0.0/16126.117.0.1 to 126.117.255.254126.117.255.25565,534
119126.118.0.0/16126.118.0.1 to 126.118.255.254126.118.255.25565,534
120126.119.0.0/16126.119.0.1 to 126.119.255.254126.119.255.25565,534
121126.120.0.0/16126.120.0.1 to 126.120.255.254126.120.255.25565,534
122126.121.0.0/16126.121.0.1 to 126.121.255.254126.121.255.25565,534
123126.122.0.0/16126.122.0.1 to 126.122.255.254126.122.255.25565,534
124126.123.0.0/16126.123.0.1 to 126.123.255.254126.123.255.25565,534
125126.124.0.0/16126.124.0.1 to 126.124.255.254126.124.255.25565,534
126126.125.0.0/16126.125.0.1 to 126.125.255.254126.125.255.25565,534
127126.126.0.0/16126.126.0.1 to 126.126.255.254126.126.255.25565,534
128126.127.0.0/16126.127.0.1 to 126.127.255.254126.127.255.25565,534
129126.128.0.0/16126.128.0.1 to 126.128.255.254126.128.255.25565,534
130126.129.0.0/16126.129.0.1 to 126.129.255.254126.129.255.25565,534
131126.130.0.0/16126.130.0.1 to 126.130.255.254126.130.255.25565,534
132126.131.0.0/16126.131.0.1 to 126.131.255.254126.131.255.25565,534
133126.132.0.0/16126.132.0.1 to 126.132.255.254126.132.255.25565,534
134126.133.0.0/16126.133.0.1 to 126.133.255.254126.133.255.25565,534
135126.134.0.0/16126.134.0.1 to 126.134.255.254126.134.255.25565,534
136126.135.0.0/16126.135.0.1 to 126.135.255.254126.135.255.25565,534
137126.136.0.0/16126.136.0.1 to 126.136.255.254126.136.255.25565,534
138126.137.0.0/16126.137.0.1 to 126.137.255.254126.137.255.25565,534
139126.138.0.0/16126.138.0.1 to 126.138.255.254126.138.255.25565,534
140126.139.0.0/16126.139.0.1 to 126.139.255.254126.139.255.25565,534
141126.140.0.0/16126.140.0.1 to 126.140.255.254126.140.255.25565,534
142126.141.0.0/16126.141.0.1 to 126.141.255.254126.141.255.25565,534
143126.142.0.0/16126.142.0.1 to 126.142.255.254126.142.255.25565,534
144126.143.0.0/16126.143.0.1 to 126.143.255.254126.143.255.25565,534
145126.144.0.0/16126.144.0.1 to 126.144.255.254126.144.255.25565,534
146126.145.0.0/16126.145.0.1 to 126.145.255.254126.145.255.25565,534
147126.146.0.0/16126.146.0.1 to 126.146.255.254126.146.255.25565,534
148126.147.0.0/16126.147.0.1 to 126.147.255.254126.147.255.25565,534
149126.148.0.0/16126.148.0.1 to 126.148.255.254126.148.255.25565,534
150126.149.0.0/16126.149.0.1 to 126.149.255.254126.149.255.25565,534
151126.150.0.0/16126.150.0.1 to 126.150.255.254126.150.255.25565,534
152126.151.0.0/16126.151.0.1 to 126.151.255.254126.151.255.25565,534
153126.152.0.0/16126.152.0.1 to 126.152.255.254126.152.255.25565,534
154126.153.0.0/16126.153.0.1 to 126.153.255.254126.153.255.25565,534
155126.154.0.0/16126.154.0.1 to 126.154.255.254126.154.255.25565,534
156126.155.0.0/16126.155.0.1 to 126.155.255.254126.155.255.25565,534
157126.156.0.0/16126.156.0.1 to 126.156.255.254126.156.255.25565,534
158126.157.0.0/16126.157.0.1 to 126.157.255.254126.157.255.25565,534
159126.158.0.0/16126.158.0.1 to 126.158.255.254126.158.255.25565,534
160126.159.0.0/16126.159.0.1 to 126.159.255.254126.159.255.25565,534
161126.160.0.0/16126.160.0.1 to 126.160.255.254126.160.255.25565,534
162126.161.0.0/16126.161.0.1 to 126.161.255.254126.161.255.25565,534
163126.162.0.0/16126.162.0.1 to 126.162.255.254126.162.255.25565,534
164126.163.0.0/16126.163.0.1 to 126.163.255.254126.163.255.25565,534
165126.164.0.0/16126.164.0.1 to 126.164.255.254126.164.255.25565,534
166126.165.0.0/16126.165.0.1 to 126.165.255.254126.165.255.25565,534
167126.166.0.0/16126.166.0.1 to 126.166.255.254126.166.255.25565,534
168126.167.0.0/16126.167.0.1 to 126.167.255.254126.167.255.25565,534
169126.168.0.0/16126.168.0.1 to 126.168.255.254126.168.255.25565,534
170126.169.0.0/16126.169.0.1 to 126.169.255.254126.169.255.25565,534
171126.170.0.0/16126.170.0.1 to 126.170.255.254126.170.255.25565,534
172126.171.0.0/16126.171.0.1 to 126.171.255.254126.171.255.25565,534
173126.172.0.0/16126.172.0.1 to 126.172.255.254126.172.255.25565,534
174126.173.0.0/16126.173.0.1 to 126.173.255.254126.173.255.25565,534
175126.174.0.0/16126.174.0.1 to 126.174.255.254126.174.255.25565,534
176126.175.0.0/16126.175.0.1 to 126.175.255.254126.175.255.25565,534
177126.176.0.0/16126.176.0.1 to 126.176.255.254126.176.255.25565,534
178126.177.0.0/16126.177.0.1 to 126.177.255.254126.177.255.25565,534
179126.178.0.0/16126.178.0.1 to 126.178.255.254126.178.255.25565,534
180126.179.0.0/16126.179.0.1 to 126.179.255.254126.179.255.25565,534
181126.180.0.0/16126.180.0.1 to 126.180.255.254126.180.255.25565,534
182126.181.0.0/16126.181.0.1 to 126.181.255.254126.181.255.25565,534
183126.182.0.0/16126.182.0.1 to 126.182.255.254126.182.255.25565,534
184126.183.0.0/16126.183.0.1 to 126.183.255.254126.183.255.25565,534
185126.184.0.0/16126.184.0.1 to 126.184.255.254126.184.255.25565,534
186126.185.0.0/16126.185.0.1 to 126.185.255.254126.185.255.25565,534
187126.186.0.0/16126.186.0.1 to 126.186.255.254126.186.255.25565,534
188126.187.0.0/16126.187.0.1 to 126.187.255.254126.187.255.25565,534
189126.188.0.0/16126.188.0.1 to 126.188.255.254126.188.255.25565,534
190126.189.0.0/16126.189.0.1 to 126.189.255.254126.189.255.25565,534
191126.190.0.0/16126.190.0.1 to 126.190.255.254126.190.255.25565,534
192126.191.0.0/16126.191.0.1 to 126.191.255.254126.191.255.25565,534
193126.192.0.0/16126.192.0.1 to 126.192.255.254126.192.255.25565,534
194126.193.0.0/16126.193.0.1 to 126.193.255.254126.193.255.25565,534
195126.194.0.0/16126.194.0.1 to 126.194.255.254126.194.255.25565,534
196126.195.0.0/16126.195.0.1 to 126.195.255.254126.195.255.25565,534
197126.196.0.0/16126.196.0.1 to 126.196.255.254126.196.255.25565,534
198126.197.0.0/16126.197.0.1 to 126.197.255.254126.197.255.25565,534
199126.198.0.0/16126.198.0.1 to 126.198.255.254126.198.255.25565,534
200126.199.0.0/16126.199.0.1 to 126.199.255.254126.199.255.25565,534
201126.200.0.0/16126.200.0.1 to 126.200.255.254126.200.255.25565,534
202126.201.0.0/16126.201.0.1 to 126.201.255.254126.201.255.25565,534
203126.202.0.0/16126.202.0.1 to 126.202.255.254126.202.255.25565,534
204126.203.0.0/16126.203.0.1 to 126.203.255.254126.203.255.25565,534
205126.204.0.0/16126.204.0.1 to 126.204.255.254126.204.255.25565,534
206126.205.0.0/16126.205.0.1 to 126.205.255.254126.205.255.25565,534
207126.206.0.0/16126.206.0.1 to 126.206.255.254126.206.255.25565,534
208126.207.0.0/16126.207.0.1 to 126.207.255.254126.207.255.25565,534
209126.208.0.0/16126.208.0.1 to 126.208.255.254126.208.255.25565,534
210126.209.0.0/16126.209.0.1 to 126.209.255.254126.209.255.25565,534
211126.210.0.0/16126.210.0.1 to 126.210.255.254126.210.255.25565,534
212126.211.0.0/16126.211.0.1 to 126.211.255.254126.211.255.25565,534
213126.212.0.0/16126.212.0.1 to 126.212.255.254126.212.255.25565,534
214126.213.0.0/16126.213.0.1 to 126.213.255.254126.213.255.25565,534
215126.214.0.0/16126.214.0.1 to 126.214.255.254126.214.255.25565,534
216126.215.0.0/16126.215.0.1 to 126.215.255.254126.215.255.25565,534
217126.216.0.0/16126.216.0.1 to 126.216.255.254126.216.255.25565,534
218126.217.0.0/16126.217.0.1 to 126.217.255.254126.217.255.25565,534
219126.218.0.0/16126.218.0.1 to 126.218.255.254126.218.255.25565,534
220126.219.0.0/16126.219.0.1 to 126.219.255.254126.219.255.25565,534
221126.220.0.0/16126.220.0.1 to 126.220.255.254126.220.255.25565,534
222126.221.0.0/16126.221.0.1 to 126.221.255.254126.221.255.25565,534
223126.222.0.0/16126.222.0.1 to 126.222.255.254126.222.255.25565,534
224126.223.0.0/16126.223.0.1 to 126.223.255.254126.223.255.25565,534
225126.224.0.0/16126.224.0.1 to 126.224.255.254126.224.255.25565,534
226126.225.0.0/16126.225.0.1 to 126.225.255.254126.225.255.25565,534
227126.226.0.0/16126.226.0.1 to 126.226.255.254126.226.255.25565,534
228126.227.0.0/16126.227.0.1 to 126.227.255.254126.227.255.25565,534
229126.228.0.0/16126.228.0.1 to 126.228.255.254126.228.255.25565,534
230126.229.0.0/16126.229.0.1 to 126.229.255.254126.229.255.25565,534
231126.230.0.0/16126.230.0.1 to 126.230.255.254126.230.255.25565,534
232126.231.0.0/16126.231.0.1 to 126.231.255.254126.231.255.25565,534
233126.232.0.0/16126.232.0.1 to 126.232.255.254126.232.255.25565,534
234126.233.0.0/16126.233.0.1 to 126.233.255.254126.233.255.25565,534
235126.234.0.0/16126.234.0.1 to 126.234.255.254126.234.255.25565,534
236126.235.0.0/16126.235.0.1 to 126.235.255.254126.235.255.25565,534
237126.236.0.0/16126.236.0.1 to 126.236.255.254126.236.255.25565,534
238126.237.0.0/16126.237.0.1 to 126.237.255.254126.237.255.25565,534
239126.238.0.0/16126.238.0.1 to 126.238.255.254126.238.255.25565,534
240126.239.0.0/16126.239.0.1 to 126.239.255.254126.239.255.25565,534
241126.240.0.0/16126.240.0.1 to 126.240.255.254126.240.255.25565,534
242126.241.0.0/16126.241.0.1 to 126.241.255.254126.241.255.25565,534
243126.242.0.0/16126.242.0.1 to 126.242.255.254126.242.255.25565,534
244126.243.0.0/16126.243.0.1 to 126.243.255.254126.243.255.25565,534
245126.244.0.0/16126.244.0.1 to 126.244.255.254126.244.255.25565,534
246126.245.0.0/16126.245.0.1 to 126.245.255.254126.245.255.25565,534
247126.246.0.0/16126.246.0.1 to 126.246.255.254126.246.255.25565,534
248126.247.0.0/16126.247.0.1 to 126.247.255.254126.247.255.25565,534
249126.248.0.0/16126.248.0.1 to 126.248.255.254126.248.255.25565,534
250126.249.0.0/16126.249.0.1 to 126.249.255.254126.249.255.25565,534
251126.250.0.0/16126.250.0.1 to 126.250.255.254126.250.255.25565,534
252126.251.0.0/16126.251.0.1 to 126.251.255.254126.251.255.25565,534
253126.252.0.0/16126.252.0.1 to 126.252.255.254126.252.255.25565,534
254126.253.0.0/16126.253.0.1 to 126.253.255.254126.253.255.25565,534
255126.254.0.0/16126.254.0.1 to 126.254.255.254126.254.255.25565,534
256126.255.0.0/16126.255.0.1 to 126.255.255.254126.255.255.25565,534

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.