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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.

Network115.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
115.0.0.0
Broadcast address
115.255.255.255
First usable
115.0.0.1
Last usable
115.255.255.254
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 73000000 · Integer 1929379840 to 1946157055
Reverse DNS zone
115.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01110011..00000000.00000000.00000000115.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network01110011..00000000.00000000.00000000115.0.0.0
Broadcast01110011..11111111.11111111.11111111115.255.255.255
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)

115.0.0.0/8 makes 256 subnets of /16.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1115.0.0.0/16115.0.0.1 to 115.0.255.254115.0.255.25565,534
2115.1.0.0/16115.1.0.1 to 115.1.255.254115.1.255.25565,534
3115.2.0.0/16115.2.0.1 to 115.2.255.254115.2.255.25565,534
4115.3.0.0/16115.3.0.1 to 115.3.255.254115.3.255.25565,534
5115.4.0.0/16115.4.0.1 to 115.4.255.254115.4.255.25565,534
6115.5.0.0/16115.5.0.1 to 115.5.255.254115.5.255.25565,534
7115.6.0.0/16115.6.0.1 to 115.6.255.254115.6.255.25565,534
8115.7.0.0/16115.7.0.1 to 115.7.255.254115.7.255.25565,534
9115.8.0.0/16115.8.0.1 to 115.8.255.254115.8.255.25565,534
10115.9.0.0/16115.9.0.1 to 115.9.255.254115.9.255.25565,534
11115.10.0.0/16115.10.0.1 to 115.10.255.254115.10.255.25565,534
12115.11.0.0/16115.11.0.1 to 115.11.255.254115.11.255.25565,534
13115.12.0.0/16115.12.0.1 to 115.12.255.254115.12.255.25565,534
14115.13.0.0/16115.13.0.1 to 115.13.255.254115.13.255.25565,534
15115.14.0.0/16115.14.0.1 to 115.14.255.254115.14.255.25565,534
16115.15.0.0/16115.15.0.1 to 115.15.255.254115.15.255.25565,534
17115.16.0.0/16115.16.0.1 to 115.16.255.254115.16.255.25565,534
18115.17.0.0/16115.17.0.1 to 115.17.255.254115.17.255.25565,534
19115.18.0.0/16115.18.0.1 to 115.18.255.254115.18.255.25565,534
20115.19.0.0/16115.19.0.1 to 115.19.255.254115.19.255.25565,534
21115.20.0.0/16115.20.0.1 to 115.20.255.254115.20.255.25565,534
22115.21.0.0/16115.21.0.1 to 115.21.255.254115.21.255.25565,534
23115.22.0.0/16115.22.0.1 to 115.22.255.254115.22.255.25565,534
24115.23.0.0/16115.23.0.1 to 115.23.255.254115.23.255.25565,534
25115.24.0.0/16115.24.0.1 to 115.24.255.254115.24.255.25565,534
26115.25.0.0/16115.25.0.1 to 115.25.255.254115.25.255.25565,534
27115.26.0.0/16115.26.0.1 to 115.26.255.254115.26.255.25565,534
28115.27.0.0/16115.27.0.1 to 115.27.255.254115.27.255.25565,534
29115.28.0.0/16115.28.0.1 to 115.28.255.254115.28.255.25565,534
30115.29.0.0/16115.29.0.1 to 115.29.255.254115.29.255.25565,534
31115.30.0.0/16115.30.0.1 to 115.30.255.254115.30.255.25565,534
32115.31.0.0/16115.31.0.1 to 115.31.255.254115.31.255.25565,534
33115.32.0.0/16115.32.0.1 to 115.32.255.254115.32.255.25565,534
34115.33.0.0/16115.33.0.1 to 115.33.255.254115.33.255.25565,534
35115.34.0.0/16115.34.0.1 to 115.34.255.254115.34.255.25565,534
36115.35.0.0/16115.35.0.1 to 115.35.255.254115.35.255.25565,534
37115.36.0.0/16115.36.0.1 to 115.36.255.254115.36.255.25565,534
38115.37.0.0/16115.37.0.1 to 115.37.255.254115.37.255.25565,534
39115.38.0.0/16115.38.0.1 to 115.38.255.254115.38.255.25565,534
40115.39.0.0/16115.39.0.1 to 115.39.255.254115.39.255.25565,534
41115.40.0.0/16115.40.0.1 to 115.40.255.254115.40.255.25565,534
42115.41.0.0/16115.41.0.1 to 115.41.255.254115.41.255.25565,534
43115.42.0.0/16115.42.0.1 to 115.42.255.254115.42.255.25565,534
44115.43.0.0/16115.43.0.1 to 115.43.255.254115.43.255.25565,534
45115.44.0.0/16115.44.0.1 to 115.44.255.254115.44.255.25565,534
46115.45.0.0/16115.45.0.1 to 115.45.255.254115.45.255.25565,534
47115.46.0.0/16115.46.0.1 to 115.46.255.254115.46.255.25565,534
48115.47.0.0/16115.47.0.1 to 115.47.255.254115.47.255.25565,534
49115.48.0.0/16115.48.0.1 to 115.48.255.254115.48.255.25565,534
50115.49.0.0/16115.49.0.1 to 115.49.255.254115.49.255.25565,534
51115.50.0.0/16115.50.0.1 to 115.50.255.254115.50.255.25565,534
52115.51.0.0/16115.51.0.1 to 115.51.255.254115.51.255.25565,534
53115.52.0.0/16115.52.0.1 to 115.52.255.254115.52.255.25565,534
54115.53.0.0/16115.53.0.1 to 115.53.255.254115.53.255.25565,534
55115.54.0.0/16115.54.0.1 to 115.54.255.254115.54.255.25565,534
56115.55.0.0/16115.55.0.1 to 115.55.255.254115.55.255.25565,534
57115.56.0.0/16115.56.0.1 to 115.56.255.254115.56.255.25565,534
58115.57.0.0/16115.57.0.1 to 115.57.255.254115.57.255.25565,534
59115.58.0.0/16115.58.0.1 to 115.58.255.254115.58.255.25565,534
60115.59.0.0/16115.59.0.1 to 115.59.255.254115.59.255.25565,534
61115.60.0.0/16115.60.0.1 to 115.60.255.254115.60.255.25565,534
62115.61.0.0/16115.61.0.1 to 115.61.255.254115.61.255.25565,534
63115.62.0.0/16115.62.0.1 to 115.62.255.254115.62.255.25565,534
64115.63.0.0/16115.63.0.1 to 115.63.255.254115.63.255.25565,534
65115.64.0.0/16115.64.0.1 to 115.64.255.254115.64.255.25565,534
66115.65.0.0/16115.65.0.1 to 115.65.255.254115.65.255.25565,534
67115.66.0.0/16115.66.0.1 to 115.66.255.254115.66.255.25565,534
68115.67.0.0/16115.67.0.1 to 115.67.255.254115.67.255.25565,534
69115.68.0.0/16115.68.0.1 to 115.68.255.254115.68.255.25565,534
70115.69.0.0/16115.69.0.1 to 115.69.255.254115.69.255.25565,534
71115.70.0.0/16115.70.0.1 to 115.70.255.254115.70.255.25565,534
72115.71.0.0/16115.71.0.1 to 115.71.255.254115.71.255.25565,534
73115.72.0.0/16115.72.0.1 to 115.72.255.254115.72.255.25565,534
74115.73.0.0/16115.73.0.1 to 115.73.255.254115.73.255.25565,534
75115.74.0.0/16115.74.0.1 to 115.74.255.254115.74.255.25565,534
76115.75.0.0/16115.75.0.1 to 115.75.255.254115.75.255.25565,534
77115.76.0.0/16115.76.0.1 to 115.76.255.254115.76.255.25565,534
78115.77.0.0/16115.77.0.1 to 115.77.255.254115.77.255.25565,534
79115.78.0.0/16115.78.0.1 to 115.78.255.254115.78.255.25565,534
80115.79.0.0/16115.79.0.1 to 115.79.255.254115.79.255.25565,534
81115.80.0.0/16115.80.0.1 to 115.80.255.254115.80.255.25565,534
82115.81.0.0/16115.81.0.1 to 115.81.255.254115.81.255.25565,534
83115.82.0.0/16115.82.0.1 to 115.82.255.254115.82.255.25565,534
84115.83.0.0/16115.83.0.1 to 115.83.255.254115.83.255.25565,534
85115.84.0.0/16115.84.0.1 to 115.84.255.254115.84.255.25565,534
86115.85.0.0/16115.85.0.1 to 115.85.255.254115.85.255.25565,534
87115.86.0.0/16115.86.0.1 to 115.86.255.254115.86.255.25565,534
88115.87.0.0/16115.87.0.1 to 115.87.255.254115.87.255.25565,534
89115.88.0.0/16115.88.0.1 to 115.88.255.254115.88.255.25565,534
90115.89.0.0/16115.89.0.1 to 115.89.255.254115.89.255.25565,534
91115.90.0.0/16115.90.0.1 to 115.90.255.254115.90.255.25565,534
92115.91.0.0/16115.91.0.1 to 115.91.255.254115.91.255.25565,534
93115.92.0.0/16115.92.0.1 to 115.92.255.254115.92.255.25565,534
94115.93.0.0/16115.93.0.1 to 115.93.255.254115.93.255.25565,534
95115.94.0.0/16115.94.0.1 to 115.94.255.254115.94.255.25565,534
96115.95.0.0/16115.95.0.1 to 115.95.255.254115.95.255.25565,534
97115.96.0.0/16115.96.0.1 to 115.96.255.254115.96.255.25565,534
98115.97.0.0/16115.97.0.1 to 115.97.255.254115.97.255.25565,534
99115.98.0.0/16115.98.0.1 to 115.98.255.254115.98.255.25565,534
100115.99.0.0/16115.99.0.1 to 115.99.255.254115.99.255.25565,534
101115.100.0.0/16115.100.0.1 to 115.100.255.254115.100.255.25565,534
102115.101.0.0/16115.101.0.1 to 115.101.255.254115.101.255.25565,534
103115.102.0.0/16115.102.0.1 to 115.102.255.254115.102.255.25565,534
104115.103.0.0/16115.103.0.1 to 115.103.255.254115.103.255.25565,534
105115.104.0.0/16115.104.0.1 to 115.104.255.254115.104.255.25565,534
106115.105.0.0/16115.105.0.1 to 115.105.255.254115.105.255.25565,534
107115.106.0.0/16115.106.0.1 to 115.106.255.254115.106.255.25565,534
108115.107.0.0/16115.107.0.1 to 115.107.255.254115.107.255.25565,534
109115.108.0.0/16115.108.0.1 to 115.108.255.254115.108.255.25565,534
110115.109.0.0/16115.109.0.1 to 115.109.255.254115.109.255.25565,534
111115.110.0.0/16115.110.0.1 to 115.110.255.254115.110.255.25565,534
112115.111.0.0/16115.111.0.1 to 115.111.255.254115.111.255.25565,534
113115.112.0.0/16115.112.0.1 to 115.112.255.254115.112.255.25565,534
114115.113.0.0/16115.113.0.1 to 115.113.255.254115.113.255.25565,534
115115.114.0.0/16115.114.0.1 to 115.114.255.254115.114.255.25565,534
116115.115.0.0/16115.115.0.1 to 115.115.255.254115.115.255.25565,534
117115.116.0.0/16115.116.0.1 to 115.116.255.254115.116.255.25565,534
118115.117.0.0/16115.117.0.1 to 115.117.255.254115.117.255.25565,534
119115.118.0.0/16115.118.0.1 to 115.118.255.254115.118.255.25565,534
120115.119.0.0/16115.119.0.1 to 115.119.255.254115.119.255.25565,534
121115.120.0.0/16115.120.0.1 to 115.120.255.254115.120.255.25565,534
122115.121.0.0/16115.121.0.1 to 115.121.255.254115.121.255.25565,534
123115.122.0.0/16115.122.0.1 to 115.122.255.254115.122.255.25565,534
124115.123.0.0/16115.123.0.1 to 115.123.255.254115.123.255.25565,534
125115.124.0.0/16115.124.0.1 to 115.124.255.254115.124.255.25565,534
126115.125.0.0/16115.125.0.1 to 115.125.255.254115.125.255.25565,534
127115.126.0.0/16115.126.0.1 to 115.126.255.254115.126.255.25565,534
128115.127.0.0/16115.127.0.1 to 115.127.255.254115.127.255.25565,534
129115.128.0.0/16115.128.0.1 to 115.128.255.254115.128.255.25565,534
130115.129.0.0/16115.129.0.1 to 115.129.255.254115.129.255.25565,534
131115.130.0.0/16115.130.0.1 to 115.130.255.254115.130.255.25565,534
132115.131.0.0/16115.131.0.1 to 115.131.255.254115.131.255.25565,534
133115.132.0.0/16115.132.0.1 to 115.132.255.254115.132.255.25565,534
134115.133.0.0/16115.133.0.1 to 115.133.255.254115.133.255.25565,534
135115.134.0.0/16115.134.0.1 to 115.134.255.254115.134.255.25565,534
136115.135.0.0/16115.135.0.1 to 115.135.255.254115.135.255.25565,534
137115.136.0.0/16115.136.0.1 to 115.136.255.254115.136.255.25565,534
138115.137.0.0/16115.137.0.1 to 115.137.255.254115.137.255.25565,534
139115.138.0.0/16115.138.0.1 to 115.138.255.254115.138.255.25565,534
140115.139.0.0/16115.139.0.1 to 115.139.255.254115.139.255.25565,534
141115.140.0.0/16115.140.0.1 to 115.140.255.254115.140.255.25565,534
142115.141.0.0/16115.141.0.1 to 115.141.255.254115.141.255.25565,534
143115.142.0.0/16115.142.0.1 to 115.142.255.254115.142.255.25565,534
144115.143.0.0/16115.143.0.1 to 115.143.255.254115.143.255.25565,534
145115.144.0.0/16115.144.0.1 to 115.144.255.254115.144.255.25565,534
146115.145.0.0/16115.145.0.1 to 115.145.255.254115.145.255.25565,534
147115.146.0.0/16115.146.0.1 to 115.146.255.254115.146.255.25565,534
148115.147.0.0/16115.147.0.1 to 115.147.255.254115.147.255.25565,534
149115.148.0.0/16115.148.0.1 to 115.148.255.254115.148.255.25565,534
150115.149.0.0/16115.149.0.1 to 115.149.255.254115.149.255.25565,534
151115.150.0.0/16115.150.0.1 to 115.150.255.254115.150.255.25565,534
152115.151.0.0/16115.151.0.1 to 115.151.255.254115.151.255.25565,534
153115.152.0.0/16115.152.0.1 to 115.152.255.254115.152.255.25565,534
154115.153.0.0/16115.153.0.1 to 115.153.255.254115.153.255.25565,534
155115.154.0.0/16115.154.0.1 to 115.154.255.254115.154.255.25565,534
156115.155.0.0/16115.155.0.1 to 115.155.255.254115.155.255.25565,534
157115.156.0.0/16115.156.0.1 to 115.156.255.254115.156.255.25565,534
158115.157.0.0/16115.157.0.1 to 115.157.255.254115.157.255.25565,534
159115.158.0.0/16115.158.0.1 to 115.158.255.254115.158.255.25565,534
160115.159.0.0/16115.159.0.1 to 115.159.255.254115.159.255.25565,534
161115.160.0.0/16115.160.0.1 to 115.160.255.254115.160.255.25565,534
162115.161.0.0/16115.161.0.1 to 115.161.255.254115.161.255.25565,534
163115.162.0.0/16115.162.0.1 to 115.162.255.254115.162.255.25565,534
164115.163.0.0/16115.163.0.1 to 115.163.255.254115.163.255.25565,534
165115.164.0.0/16115.164.0.1 to 115.164.255.254115.164.255.25565,534
166115.165.0.0/16115.165.0.1 to 115.165.255.254115.165.255.25565,534
167115.166.0.0/16115.166.0.1 to 115.166.255.254115.166.255.25565,534
168115.167.0.0/16115.167.0.1 to 115.167.255.254115.167.255.25565,534
169115.168.0.0/16115.168.0.1 to 115.168.255.254115.168.255.25565,534
170115.169.0.0/16115.169.0.1 to 115.169.255.254115.169.255.25565,534
171115.170.0.0/16115.170.0.1 to 115.170.255.254115.170.255.25565,534
172115.171.0.0/16115.171.0.1 to 115.171.255.254115.171.255.25565,534
173115.172.0.0/16115.172.0.1 to 115.172.255.254115.172.255.25565,534
174115.173.0.0/16115.173.0.1 to 115.173.255.254115.173.255.25565,534
175115.174.0.0/16115.174.0.1 to 115.174.255.254115.174.255.25565,534
176115.175.0.0/16115.175.0.1 to 115.175.255.254115.175.255.25565,534
177115.176.0.0/16115.176.0.1 to 115.176.255.254115.176.255.25565,534
178115.177.0.0/16115.177.0.1 to 115.177.255.254115.177.255.25565,534
179115.178.0.0/16115.178.0.1 to 115.178.255.254115.178.255.25565,534
180115.179.0.0/16115.179.0.1 to 115.179.255.254115.179.255.25565,534
181115.180.0.0/16115.180.0.1 to 115.180.255.254115.180.255.25565,534
182115.181.0.0/16115.181.0.1 to 115.181.255.254115.181.255.25565,534
183115.182.0.0/16115.182.0.1 to 115.182.255.254115.182.255.25565,534
184115.183.0.0/16115.183.0.1 to 115.183.255.254115.183.255.25565,534
185115.184.0.0/16115.184.0.1 to 115.184.255.254115.184.255.25565,534
186115.185.0.0/16115.185.0.1 to 115.185.255.254115.185.255.25565,534
187115.186.0.0/16115.186.0.1 to 115.186.255.254115.186.255.25565,534
188115.187.0.0/16115.187.0.1 to 115.187.255.254115.187.255.25565,534
189115.188.0.0/16115.188.0.1 to 115.188.255.254115.188.255.25565,534
190115.189.0.0/16115.189.0.1 to 115.189.255.254115.189.255.25565,534
191115.190.0.0/16115.190.0.1 to 115.190.255.254115.190.255.25565,534
192115.191.0.0/16115.191.0.1 to 115.191.255.254115.191.255.25565,534
193115.192.0.0/16115.192.0.1 to 115.192.255.254115.192.255.25565,534
194115.193.0.0/16115.193.0.1 to 115.193.255.254115.193.255.25565,534
195115.194.0.0/16115.194.0.1 to 115.194.255.254115.194.255.25565,534
196115.195.0.0/16115.195.0.1 to 115.195.255.254115.195.255.25565,534
197115.196.0.0/16115.196.0.1 to 115.196.255.254115.196.255.25565,534
198115.197.0.0/16115.197.0.1 to 115.197.255.254115.197.255.25565,534
199115.198.0.0/16115.198.0.1 to 115.198.255.254115.198.255.25565,534
200115.199.0.0/16115.199.0.1 to 115.199.255.254115.199.255.25565,534
201115.200.0.0/16115.200.0.1 to 115.200.255.254115.200.255.25565,534
202115.201.0.0/16115.201.0.1 to 115.201.255.254115.201.255.25565,534
203115.202.0.0/16115.202.0.1 to 115.202.255.254115.202.255.25565,534
204115.203.0.0/16115.203.0.1 to 115.203.255.254115.203.255.25565,534
205115.204.0.0/16115.204.0.1 to 115.204.255.254115.204.255.25565,534
206115.205.0.0/16115.205.0.1 to 115.205.255.254115.205.255.25565,534
207115.206.0.0/16115.206.0.1 to 115.206.255.254115.206.255.25565,534
208115.207.0.0/16115.207.0.1 to 115.207.255.254115.207.255.25565,534
209115.208.0.0/16115.208.0.1 to 115.208.255.254115.208.255.25565,534
210115.209.0.0/16115.209.0.1 to 115.209.255.254115.209.255.25565,534
211115.210.0.0/16115.210.0.1 to 115.210.255.254115.210.255.25565,534
212115.211.0.0/16115.211.0.1 to 115.211.255.254115.211.255.25565,534
213115.212.0.0/16115.212.0.1 to 115.212.255.254115.212.255.25565,534
214115.213.0.0/16115.213.0.1 to 115.213.255.254115.213.255.25565,534
215115.214.0.0/16115.214.0.1 to 115.214.255.254115.214.255.25565,534
216115.215.0.0/16115.215.0.1 to 115.215.255.254115.215.255.25565,534
217115.216.0.0/16115.216.0.1 to 115.216.255.254115.216.255.25565,534
218115.217.0.0/16115.217.0.1 to 115.217.255.254115.217.255.25565,534
219115.218.0.0/16115.218.0.1 to 115.218.255.254115.218.255.25565,534
220115.219.0.0/16115.219.0.1 to 115.219.255.254115.219.255.25565,534
221115.220.0.0/16115.220.0.1 to 115.220.255.254115.220.255.25565,534
222115.221.0.0/16115.221.0.1 to 115.221.255.254115.221.255.25565,534
223115.222.0.0/16115.222.0.1 to 115.222.255.254115.222.255.25565,534
224115.223.0.0/16115.223.0.1 to 115.223.255.254115.223.255.25565,534
225115.224.0.0/16115.224.0.1 to 115.224.255.254115.224.255.25565,534
226115.225.0.0/16115.225.0.1 to 115.225.255.254115.225.255.25565,534
227115.226.0.0/16115.226.0.1 to 115.226.255.254115.226.255.25565,534
228115.227.0.0/16115.227.0.1 to 115.227.255.254115.227.255.25565,534
229115.228.0.0/16115.228.0.1 to 115.228.255.254115.228.255.25565,534
230115.229.0.0/16115.229.0.1 to 115.229.255.254115.229.255.25565,534
231115.230.0.0/16115.230.0.1 to 115.230.255.254115.230.255.25565,534
232115.231.0.0/16115.231.0.1 to 115.231.255.254115.231.255.25565,534
233115.232.0.0/16115.232.0.1 to 115.232.255.254115.232.255.25565,534
234115.233.0.0/16115.233.0.1 to 115.233.255.254115.233.255.25565,534
235115.234.0.0/16115.234.0.1 to 115.234.255.254115.234.255.25565,534
236115.235.0.0/16115.235.0.1 to 115.235.255.254115.235.255.25565,534
237115.236.0.0/16115.236.0.1 to 115.236.255.254115.236.255.25565,534
238115.237.0.0/16115.237.0.1 to 115.237.255.254115.237.255.25565,534
239115.238.0.0/16115.238.0.1 to 115.238.255.254115.238.255.25565,534
240115.239.0.0/16115.239.0.1 to 115.239.255.254115.239.255.25565,534
241115.240.0.0/16115.240.0.1 to 115.240.255.254115.240.255.25565,534
242115.241.0.0/16115.241.0.1 to 115.241.255.254115.241.255.25565,534
243115.242.0.0/16115.242.0.1 to 115.242.255.254115.242.255.25565,534
244115.243.0.0/16115.243.0.1 to 115.243.255.254115.243.255.25565,534
245115.244.0.0/16115.244.0.1 to 115.244.255.254115.244.255.25565,534
246115.245.0.0/16115.245.0.1 to 115.245.255.254115.245.255.25565,534
247115.246.0.0/16115.246.0.1 to 115.246.255.254115.246.255.25565,534
248115.247.0.0/16115.247.0.1 to 115.247.255.254115.247.255.25565,534
249115.248.0.0/16115.248.0.1 to 115.248.255.254115.248.255.25565,534
250115.249.0.0/16115.249.0.1 to 115.249.255.254115.249.255.25565,534
251115.250.0.0/16115.250.0.1 to 115.250.255.254115.250.255.25565,534
252115.251.0.0/16115.251.0.1 to 115.251.255.254115.251.255.25565,534
253115.252.0.0/16115.252.0.1 to 115.252.255.254115.252.255.25565,534
254115.253.0.0/16115.253.0.1 to 115.253.255.254115.253.255.25565,534
255115.254.0.0/16115.254.0.1 to 115.254.255.254115.254.255.25565,534
256115.255.0.0/16115.255.0.1 to 115.255.255.254115.255.255.25565,534

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.