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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.

Network87.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
87.0.0.0
Broadcast address
87.255.255.255
First usable
87.0.0.1
Last usable
87.255.255.254
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 57000000 · Integer 1459617792 to 1476395007
Reverse DNS zone
87.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01010111..00000000.00000000.0000000087.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network01010111..00000000.00000000.0000000087.0.0.0
Broadcast01010111..11111111.11111111.1111111187.255.255.255
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)

87.0.0.0/8 makes 256 subnets of /16.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
187.0.0.0/1687.0.0.1 to 87.0.255.25487.0.255.25565,534
287.1.0.0/1687.1.0.1 to 87.1.255.25487.1.255.25565,534
387.2.0.0/1687.2.0.1 to 87.2.255.25487.2.255.25565,534
487.3.0.0/1687.3.0.1 to 87.3.255.25487.3.255.25565,534
587.4.0.0/1687.4.0.1 to 87.4.255.25487.4.255.25565,534
687.5.0.0/1687.5.0.1 to 87.5.255.25487.5.255.25565,534
787.6.0.0/1687.6.0.1 to 87.6.255.25487.6.255.25565,534
887.7.0.0/1687.7.0.1 to 87.7.255.25487.7.255.25565,534
987.8.0.0/1687.8.0.1 to 87.8.255.25487.8.255.25565,534
1087.9.0.0/1687.9.0.1 to 87.9.255.25487.9.255.25565,534
1187.10.0.0/1687.10.0.1 to 87.10.255.25487.10.255.25565,534
1287.11.0.0/1687.11.0.1 to 87.11.255.25487.11.255.25565,534
1387.12.0.0/1687.12.0.1 to 87.12.255.25487.12.255.25565,534
1487.13.0.0/1687.13.0.1 to 87.13.255.25487.13.255.25565,534
1587.14.0.0/1687.14.0.1 to 87.14.255.25487.14.255.25565,534
1687.15.0.0/1687.15.0.1 to 87.15.255.25487.15.255.25565,534
1787.16.0.0/1687.16.0.1 to 87.16.255.25487.16.255.25565,534
1887.17.0.0/1687.17.0.1 to 87.17.255.25487.17.255.25565,534
1987.18.0.0/1687.18.0.1 to 87.18.255.25487.18.255.25565,534
2087.19.0.0/1687.19.0.1 to 87.19.255.25487.19.255.25565,534
2187.20.0.0/1687.20.0.1 to 87.20.255.25487.20.255.25565,534
2287.21.0.0/1687.21.0.1 to 87.21.255.25487.21.255.25565,534
2387.22.0.0/1687.22.0.1 to 87.22.255.25487.22.255.25565,534
2487.23.0.0/1687.23.0.1 to 87.23.255.25487.23.255.25565,534
2587.24.0.0/1687.24.0.1 to 87.24.255.25487.24.255.25565,534
2687.25.0.0/1687.25.0.1 to 87.25.255.25487.25.255.25565,534
2787.26.0.0/1687.26.0.1 to 87.26.255.25487.26.255.25565,534
2887.27.0.0/1687.27.0.1 to 87.27.255.25487.27.255.25565,534
2987.28.0.0/1687.28.0.1 to 87.28.255.25487.28.255.25565,534
3087.29.0.0/1687.29.0.1 to 87.29.255.25487.29.255.25565,534
3187.30.0.0/1687.30.0.1 to 87.30.255.25487.30.255.25565,534
3287.31.0.0/1687.31.0.1 to 87.31.255.25487.31.255.25565,534
3387.32.0.0/1687.32.0.1 to 87.32.255.25487.32.255.25565,534
3487.33.0.0/1687.33.0.1 to 87.33.255.25487.33.255.25565,534
3587.34.0.0/1687.34.0.1 to 87.34.255.25487.34.255.25565,534
3687.35.0.0/1687.35.0.1 to 87.35.255.25487.35.255.25565,534
3787.36.0.0/1687.36.0.1 to 87.36.255.25487.36.255.25565,534
3887.37.0.0/1687.37.0.1 to 87.37.255.25487.37.255.25565,534
3987.38.0.0/1687.38.0.1 to 87.38.255.25487.38.255.25565,534
4087.39.0.0/1687.39.0.1 to 87.39.255.25487.39.255.25565,534
4187.40.0.0/1687.40.0.1 to 87.40.255.25487.40.255.25565,534
4287.41.0.0/1687.41.0.1 to 87.41.255.25487.41.255.25565,534
4387.42.0.0/1687.42.0.1 to 87.42.255.25487.42.255.25565,534
4487.43.0.0/1687.43.0.1 to 87.43.255.25487.43.255.25565,534
4587.44.0.0/1687.44.0.1 to 87.44.255.25487.44.255.25565,534
4687.45.0.0/1687.45.0.1 to 87.45.255.25487.45.255.25565,534
4787.46.0.0/1687.46.0.1 to 87.46.255.25487.46.255.25565,534
4887.47.0.0/1687.47.0.1 to 87.47.255.25487.47.255.25565,534
4987.48.0.0/1687.48.0.1 to 87.48.255.25487.48.255.25565,534
5087.49.0.0/1687.49.0.1 to 87.49.255.25487.49.255.25565,534
5187.50.0.0/1687.50.0.1 to 87.50.255.25487.50.255.25565,534
5287.51.0.0/1687.51.0.1 to 87.51.255.25487.51.255.25565,534
5387.52.0.0/1687.52.0.1 to 87.52.255.25487.52.255.25565,534
5487.53.0.0/1687.53.0.1 to 87.53.255.25487.53.255.25565,534
5587.54.0.0/1687.54.0.1 to 87.54.255.25487.54.255.25565,534
5687.55.0.0/1687.55.0.1 to 87.55.255.25487.55.255.25565,534
5787.56.0.0/1687.56.0.1 to 87.56.255.25487.56.255.25565,534
5887.57.0.0/1687.57.0.1 to 87.57.255.25487.57.255.25565,534
5987.58.0.0/1687.58.0.1 to 87.58.255.25487.58.255.25565,534
6087.59.0.0/1687.59.0.1 to 87.59.255.25487.59.255.25565,534
6187.60.0.0/1687.60.0.1 to 87.60.255.25487.60.255.25565,534
6287.61.0.0/1687.61.0.1 to 87.61.255.25487.61.255.25565,534
6387.62.0.0/1687.62.0.1 to 87.62.255.25487.62.255.25565,534
6487.63.0.0/1687.63.0.1 to 87.63.255.25487.63.255.25565,534
6587.64.0.0/1687.64.0.1 to 87.64.255.25487.64.255.25565,534
6687.65.0.0/1687.65.0.1 to 87.65.255.25487.65.255.25565,534
6787.66.0.0/1687.66.0.1 to 87.66.255.25487.66.255.25565,534
6887.67.0.0/1687.67.0.1 to 87.67.255.25487.67.255.25565,534
6987.68.0.0/1687.68.0.1 to 87.68.255.25487.68.255.25565,534
7087.69.0.0/1687.69.0.1 to 87.69.255.25487.69.255.25565,534
7187.70.0.0/1687.70.0.1 to 87.70.255.25487.70.255.25565,534
7287.71.0.0/1687.71.0.1 to 87.71.255.25487.71.255.25565,534
7387.72.0.0/1687.72.0.1 to 87.72.255.25487.72.255.25565,534
7487.73.0.0/1687.73.0.1 to 87.73.255.25487.73.255.25565,534
7587.74.0.0/1687.74.0.1 to 87.74.255.25487.74.255.25565,534
7687.75.0.0/1687.75.0.1 to 87.75.255.25487.75.255.25565,534
7787.76.0.0/1687.76.0.1 to 87.76.255.25487.76.255.25565,534
7887.77.0.0/1687.77.0.1 to 87.77.255.25487.77.255.25565,534
7987.78.0.0/1687.78.0.1 to 87.78.255.25487.78.255.25565,534
8087.79.0.0/1687.79.0.1 to 87.79.255.25487.79.255.25565,534
8187.80.0.0/1687.80.0.1 to 87.80.255.25487.80.255.25565,534
8287.81.0.0/1687.81.0.1 to 87.81.255.25487.81.255.25565,534
8387.82.0.0/1687.82.0.1 to 87.82.255.25487.82.255.25565,534
8487.83.0.0/1687.83.0.1 to 87.83.255.25487.83.255.25565,534
8587.84.0.0/1687.84.0.1 to 87.84.255.25487.84.255.25565,534
8687.85.0.0/1687.85.0.1 to 87.85.255.25487.85.255.25565,534
8787.86.0.0/1687.86.0.1 to 87.86.255.25487.86.255.25565,534
8887.87.0.0/1687.87.0.1 to 87.87.255.25487.87.255.25565,534
8987.88.0.0/1687.88.0.1 to 87.88.255.25487.88.255.25565,534
9087.89.0.0/1687.89.0.1 to 87.89.255.25487.89.255.25565,534
9187.90.0.0/1687.90.0.1 to 87.90.255.25487.90.255.25565,534
9287.91.0.0/1687.91.0.1 to 87.91.255.25487.91.255.25565,534
9387.92.0.0/1687.92.0.1 to 87.92.255.25487.92.255.25565,534
9487.93.0.0/1687.93.0.1 to 87.93.255.25487.93.255.25565,534
9587.94.0.0/1687.94.0.1 to 87.94.255.25487.94.255.25565,534
9687.95.0.0/1687.95.0.1 to 87.95.255.25487.95.255.25565,534
9787.96.0.0/1687.96.0.1 to 87.96.255.25487.96.255.25565,534
9887.97.0.0/1687.97.0.1 to 87.97.255.25487.97.255.25565,534
9987.98.0.0/1687.98.0.1 to 87.98.255.25487.98.255.25565,534
10087.99.0.0/1687.99.0.1 to 87.99.255.25487.99.255.25565,534
10187.100.0.0/1687.100.0.1 to 87.100.255.25487.100.255.25565,534
10287.101.0.0/1687.101.0.1 to 87.101.255.25487.101.255.25565,534
10387.102.0.0/1687.102.0.1 to 87.102.255.25487.102.255.25565,534
10487.103.0.0/1687.103.0.1 to 87.103.255.25487.103.255.25565,534
10587.104.0.0/1687.104.0.1 to 87.104.255.25487.104.255.25565,534
10687.105.0.0/1687.105.0.1 to 87.105.255.25487.105.255.25565,534
10787.106.0.0/1687.106.0.1 to 87.106.255.25487.106.255.25565,534
10887.107.0.0/1687.107.0.1 to 87.107.255.25487.107.255.25565,534
10987.108.0.0/1687.108.0.1 to 87.108.255.25487.108.255.25565,534
11087.109.0.0/1687.109.0.1 to 87.109.255.25487.109.255.25565,534
11187.110.0.0/1687.110.0.1 to 87.110.255.25487.110.255.25565,534
11287.111.0.0/1687.111.0.1 to 87.111.255.25487.111.255.25565,534
11387.112.0.0/1687.112.0.1 to 87.112.255.25487.112.255.25565,534
11487.113.0.0/1687.113.0.1 to 87.113.255.25487.113.255.25565,534
11587.114.0.0/1687.114.0.1 to 87.114.255.25487.114.255.25565,534
11687.115.0.0/1687.115.0.1 to 87.115.255.25487.115.255.25565,534
11787.116.0.0/1687.116.0.1 to 87.116.255.25487.116.255.25565,534
11887.117.0.0/1687.117.0.1 to 87.117.255.25487.117.255.25565,534
11987.118.0.0/1687.118.0.1 to 87.118.255.25487.118.255.25565,534
12087.119.0.0/1687.119.0.1 to 87.119.255.25487.119.255.25565,534
12187.120.0.0/1687.120.0.1 to 87.120.255.25487.120.255.25565,534
12287.121.0.0/1687.121.0.1 to 87.121.255.25487.121.255.25565,534
12387.122.0.0/1687.122.0.1 to 87.122.255.25487.122.255.25565,534
12487.123.0.0/1687.123.0.1 to 87.123.255.25487.123.255.25565,534
12587.124.0.0/1687.124.0.1 to 87.124.255.25487.124.255.25565,534
12687.125.0.0/1687.125.0.1 to 87.125.255.25487.125.255.25565,534
12787.126.0.0/1687.126.0.1 to 87.126.255.25487.126.255.25565,534
12887.127.0.0/1687.127.0.1 to 87.127.255.25487.127.255.25565,534
12987.128.0.0/1687.128.0.1 to 87.128.255.25487.128.255.25565,534
13087.129.0.0/1687.129.0.1 to 87.129.255.25487.129.255.25565,534
13187.130.0.0/1687.130.0.1 to 87.130.255.25487.130.255.25565,534
13287.131.0.0/1687.131.0.1 to 87.131.255.25487.131.255.25565,534
13387.132.0.0/1687.132.0.1 to 87.132.255.25487.132.255.25565,534
13487.133.0.0/1687.133.0.1 to 87.133.255.25487.133.255.25565,534
13587.134.0.0/1687.134.0.1 to 87.134.255.25487.134.255.25565,534
13687.135.0.0/1687.135.0.1 to 87.135.255.25487.135.255.25565,534
13787.136.0.0/1687.136.0.1 to 87.136.255.25487.136.255.25565,534
13887.137.0.0/1687.137.0.1 to 87.137.255.25487.137.255.25565,534
13987.138.0.0/1687.138.0.1 to 87.138.255.25487.138.255.25565,534
14087.139.0.0/1687.139.0.1 to 87.139.255.25487.139.255.25565,534
14187.140.0.0/1687.140.0.1 to 87.140.255.25487.140.255.25565,534
14287.141.0.0/1687.141.0.1 to 87.141.255.25487.141.255.25565,534
14387.142.0.0/1687.142.0.1 to 87.142.255.25487.142.255.25565,534
14487.143.0.0/1687.143.0.1 to 87.143.255.25487.143.255.25565,534
14587.144.0.0/1687.144.0.1 to 87.144.255.25487.144.255.25565,534
14687.145.0.0/1687.145.0.1 to 87.145.255.25487.145.255.25565,534
14787.146.0.0/1687.146.0.1 to 87.146.255.25487.146.255.25565,534
14887.147.0.0/1687.147.0.1 to 87.147.255.25487.147.255.25565,534
14987.148.0.0/1687.148.0.1 to 87.148.255.25487.148.255.25565,534
15087.149.0.0/1687.149.0.1 to 87.149.255.25487.149.255.25565,534
15187.150.0.0/1687.150.0.1 to 87.150.255.25487.150.255.25565,534
15287.151.0.0/1687.151.0.1 to 87.151.255.25487.151.255.25565,534
15387.152.0.0/1687.152.0.1 to 87.152.255.25487.152.255.25565,534
15487.153.0.0/1687.153.0.1 to 87.153.255.25487.153.255.25565,534
15587.154.0.0/1687.154.0.1 to 87.154.255.25487.154.255.25565,534
15687.155.0.0/1687.155.0.1 to 87.155.255.25487.155.255.25565,534
15787.156.0.0/1687.156.0.1 to 87.156.255.25487.156.255.25565,534
15887.157.0.0/1687.157.0.1 to 87.157.255.25487.157.255.25565,534
15987.158.0.0/1687.158.0.1 to 87.158.255.25487.158.255.25565,534
16087.159.0.0/1687.159.0.1 to 87.159.255.25487.159.255.25565,534
16187.160.0.0/1687.160.0.1 to 87.160.255.25487.160.255.25565,534
16287.161.0.0/1687.161.0.1 to 87.161.255.25487.161.255.25565,534
16387.162.0.0/1687.162.0.1 to 87.162.255.25487.162.255.25565,534
16487.163.0.0/1687.163.0.1 to 87.163.255.25487.163.255.25565,534
16587.164.0.0/1687.164.0.1 to 87.164.255.25487.164.255.25565,534
16687.165.0.0/1687.165.0.1 to 87.165.255.25487.165.255.25565,534
16787.166.0.0/1687.166.0.1 to 87.166.255.25487.166.255.25565,534
16887.167.0.0/1687.167.0.1 to 87.167.255.25487.167.255.25565,534
16987.168.0.0/1687.168.0.1 to 87.168.255.25487.168.255.25565,534
17087.169.0.0/1687.169.0.1 to 87.169.255.25487.169.255.25565,534
17187.170.0.0/1687.170.0.1 to 87.170.255.25487.170.255.25565,534
17287.171.0.0/1687.171.0.1 to 87.171.255.25487.171.255.25565,534
17387.172.0.0/1687.172.0.1 to 87.172.255.25487.172.255.25565,534
17487.173.0.0/1687.173.0.1 to 87.173.255.25487.173.255.25565,534
17587.174.0.0/1687.174.0.1 to 87.174.255.25487.174.255.25565,534
17687.175.0.0/1687.175.0.1 to 87.175.255.25487.175.255.25565,534
17787.176.0.0/1687.176.0.1 to 87.176.255.25487.176.255.25565,534
17887.177.0.0/1687.177.0.1 to 87.177.255.25487.177.255.25565,534
17987.178.0.0/1687.178.0.1 to 87.178.255.25487.178.255.25565,534
18087.179.0.0/1687.179.0.1 to 87.179.255.25487.179.255.25565,534
18187.180.0.0/1687.180.0.1 to 87.180.255.25487.180.255.25565,534
18287.181.0.0/1687.181.0.1 to 87.181.255.25487.181.255.25565,534
18387.182.0.0/1687.182.0.1 to 87.182.255.25487.182.255.25565,534
18487.183.0.0/1687.183.0.1 to 87.183.255.25487.183.255.25565,534
18587.184.0.0/1687.184.0.1 to 87.184.255.25487.184.255.25565,534
18687.185.0.0/1687.185.0.1 to 87.185.255.25487.185.255.25565,534
18787.186.0.0/1687.186.0.1 to 87.186.255.25487.186.255.25565,534
18887.187.0.0/1687.187.0.1 to 87.187.255.25487.187.255.25565,534
18987.188.0.0/1687.188.0.1 to 87.188.255.25487.188.255.25565,534
19087.189.0.0/1687.189.0.1 to 87.189.255.25487.189.255.25565,534
19187.190.0.0/1687.190.0.1 to 87.190.255.25487.190.255.25565,534
19287.191.0.0/1687.191.0.1 to 87.191.255.25487.191.255.25565,534
19387.192.0.0/1687.192.0.1 to 87.192.255.25487.192.255.25565,534
19487.193.0.0/1687.193.0.1 to 87.193.255.25487.193.255.25565,534
19587.194.0.0/1687.194.0.1 to 87.194.255.25487.194.255.25565,534
19687.195.0.0/1687.195.0.1 to 87.195.255.25487.195.255.25565,534
19787.196.0.0/1687.196.0.1 to 87.196.255.25487.196.255.25565,534
19887.197.0.0/1687.197.0.1 to 87.197.255.25487.197.255.25565,534
19987.198.0.0/1687.198.0.1 to 87.198.255.25487.198.255.25565,534
20087.199.0.0/1687.199.0.1 to 87.199.255.25487.199.255.25565,534
20187.200.0.0/1687.200.0.1 to 87.200.255.25487.200.255.25565,534
20287.201.0.0/1687.201.0.1 to 87.201.255.25487.201.255.25565,534
20387.202.0.0/1687.202.0.1 to 87.202.255.25487.202.255.25565,534
20487.203.0.0/1687.203.0.1 to 87.203.255.25487.203.255.25565,534
20587.204.0.0/1687.204.0.1 to 87.204.255.25487.204.255.25565,534
20687.205.0.0/1687.205.0.1 to 87.205.255.25487.205.255.25565,534
20787.206.0.0/1687.206.0.1 to 87.206.255.25487.206.255.25565,534
20887.207.0.0/1687.207.0.1 to 87.207.255.25487.207.255.25565,534
20987.208.0.0/1687.208.0.1 to 87.208.255.25487.208.255.25565,534
21087.209.0.0/1687.209.0.1 to 87.209.255.25487.209.255.25565,534
21187.210.0.0/1687.210.0.1 to 87.210.255.25487.210.255.25565,534
21287.211.0.0/1687.211.0.1 to 87.211.255.25487.211.255.25565,534
21387.212.0.0/1687.212.0.1 to 87.212.255.25487.212.255.25565,534
21487.213.0.0/1687.213.0.1 to 87.213.255.25487.213.255.25565,534
21587.214.0.0/1687.214.0.1 to 87.214.255.25487.214.255.25565,534
21687.215.0.0/1687.215.0.1 to 87.215.255.25487.215.255.25565,534
21787.216.0.0/1687.216.0.1 to 87.216.255.25487.216.255.25565,534
21887.217.0.0/1687.217.0.1 to 87.217.255.25487.217.255.25565,534
21987.218.0.0/1687.218.0.1 to 87.218.255.25487.218.255.25565,534
22087.219.0.0/1687.219.0.1 to 87.219.255.25487.219.255.25565,534
22187.220.0.0/1687.220.0.1 to 87.220.255.25487.220.255.25565,534
22287.221.0.0/1687.221.0.1 to 87.221.255.25487.221.255.25565,534
22387.222.0.0/1687.222.0.1 to 87.222.255.25487.222.255.25565,534
22487.223.0.0/1687.223.0.1 to 87.223.255.25487.223.255.25565,534
22587.224.0.0/1687.224.0.1 to 87.224.255.25487.224.255.25565,534
22687.225.0.0/1687.225.0.1 to 87.225.255.25487.225.255.25565,534
22787.226.0.0/1687.226.0.1 to 87.226.255.25487.226.255.25565,534
22887.227.0.0/1687.227.0.1 to 87.227.255.25487.227.255.25565,534
22987.228.0.0/1687.228.0.1 to 87.228.255.25487.228.255.25565,534
23087.229.0.0/1687.229.0.1 to 87.229.255.25487.229.255.25565,534
23187.230.0.0/1687.230.0.1 to 87.230.255.25487.230.255.25565,534
23287.231.0.0/1687.231.0.1 to 87.231.255.25487.231.255.25565,534
23387.232.0.0/1687.232.0.1 to 87.232.255.25487.232.255.25565,534
23487.233.0.0/1687.233.0.1 to 87.233.255.25487.233.255.25565,534
23587.234.0.0/1687.234.0.1 to 87.234.255.25487.234.255.25565,534
23687.235.0.0/1687.235.0.1 to 87.235.255.25487.235.255.25565,534
23787.236.0.0/1687.236.0.1 to 87.236.255.25487.236.255.25565,534
23887.237.0.0/1687.237.0.1 to 87.237.255.25487.237.255.25565,534
23987.238.0.0/1687.238.0.1 to 87.238.255.25487.238.255.25565,534
24087.239.0.0/1687.239.0.1 to 87.239.255.25487.239.255.25565,534
24187.240.0.0/1687.240.0.1 to 87.240.255.25487.240.255.25565,534
24287.241.0.0/1687.241.0.1 to 87.241.255.25487.241.255.25565,534
24387.242.0.0/1687.242.0.1 to 87.242.255.25487.242.255.25565,534
24487.243.0.0/1687.243.0.1 to 87.243.255.25487.243.255.25565,534
24587.244.0.0/1687.244.0.1 to 87.244.255.25487.244.255.25565,534
24687.245.0.0/1687.245.0.1 to 87.245.255.25487.245.255.25565,534
24787.246.0.0/1687.246.0.1 to 87.246.255.25487.246.255.25565,534
24887.247.0.0/1687.247.0.1 to 87.247.255.25487.247.255.25565,534
24987.248.0.0/1687.248.0.1 to 87.248.255.25487.248.255.25565,534
25087.249.0.0/1687.249.0.1 to 87.249.255.25487.249.255.25565,534
25187.250.0.0/1687.250.0.1 to 87.250.255.25487.250.255.25565,534
25287.251.0.0/1687.251.0.1 to 87.251.255.25487.251.255.25565,534
25387.252.0.0/1687.252.0.1 to 87.252.255.25487.252.255.25565,534
25487.253.0.0/1687.253.0.1 to 87.253.255.25487.253.255.25565,534
25587.254.0.0/1687.254.0.1 to 87.254.255.25487.254.255.25565,534
25687.255.0.0/1687.255.0.1 to 87.255.255.25487.255.255.25565,534

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.