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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.

Network87.96.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
87.96.0.0
Broadcast address
87.97.255.255
First usable
87.96.0.1
Last usable
87.97.255.254
Usable hosts
131,070 (131,072 less the network and broadcast addresses)
Subnet mask
255.254.0.0
Wildcard mask
0.1.255.255 (Cisco ACLs, OSPF)
Prefix length
/15
Type
Public public
Old class
A (default /8)
As numbers
Hex 57600000 · Integer 1465909248 to 1466040319
Reverse DNS zones
96.87.in-addr.arpa
97.87.in-addr.arpa
/15 is not on a 8-bit boundary, so it takes 2 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01010111.01100000.00000000.0000000087.96.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network01010111.01100000.00000000.0000000087.96.0.0
Broadcast01010111.01100001.11111111.1111111187.97.255.255
Split into smaller subnets/24
/16 (2)/17 (4)/18 (8)/19 (16)/20 (32)/21 (64)/22 (128)/23 (256)/24 (512)/25 (1,024)/26 (2,048)/27 (4,096)

87.96.0.0/15 makes 512 subnets of /24; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
187.96.0.0/2487.96.0.1 to 87.96.0.25487.96.0.255254
287.96.1.0/2487.96.1.1 to 87.96.1.25487.96.1.255254
387.96.2.0/2487.96.2.1 to 87.96.2.25487.96.2.255254
487.96.3.0/2487.96.3.1 to 87.96.3.25487.96.3.255254
587.96.4.0/2487.96.4.1 to 87.96.4.25487.96.4.255254
687.96.5.0/2487.96.5.1 to 87.96.5.25487.96.5.255254
787.96.6.0/2487.96.6.1 to 87.96.6.25487.96.6.255254
887.96.7.0/2487.96.7.1 to 87.96.7.25487.96.7.255254
987.96.8.0/2487.96.8.1 to 87.96.8.25487.96.8.255254
1087.96.9.0/2487.96.9.1 to 87.96.9.25487.96.9.255254
1187.96.10.0/2487.96.10.1 to 87.96.10.25487.96.10.255254
1287.96.11.0/2487.96.11.1 to 87.96.11.25487.96.11.255254
1387.96.12.0/2487.96.12.1 to 87.96.12.25487.96.12.255254
1487.96.13.0/2487.96.13.1 to 87.96.13.25487.96.13.255254
1587.96.14.0/2487.96.14.1 to 87.96.14.25487.96.14.255254
1687.96.15.0/2487.96.15.1 to 87.96.15.25487.96.15.255254
1787.96.16.0/2487.96.16.1 to 87.96.16.25487.96.16.255254
1887.96.17.0/2487.96.17.1 to 87.96.17.25487.96.17.255254
1987.96.18.0/2487.96.18.1 to 87.96.18.25487.96.18.255254
2087.96.19.0/2487.96.19.1 to 87.96.19.25487.96.19.255254
2187.96.20.0/2487.96.20.1 to 87.96.20.25487.96.20.255254
2287.96.21.0/2487.96.21.1 to 87.96.21.25487.96.21.255254
2387.96.22.0/2487.96.22.1 to 87.96.22.25487.96.22.255254
2487.96.23.0/2487.96.23.1 to 87.96.23.25487.96.23.255254
2587.96.24.0/2487.96.24.1 to 87.96.24.25487.96.24.255254
2687.96.25.0/2487.96.25.1 to 87.96.25.25487.96.25.255254
2787.96.26.0/2487.96.26.1 to 87.96.26.25487.96.26.255254
2887.96.27.0/2487.96.27.1 to 87.96.27.25487.96.27.255254
2987.96.28.0/2487.96.28.1 to 87.96.28.25487.96.28.255254
3087.96.29.0/2487.96.29.1 to 87.96.29.25487.96.29.255254
3187.96.30.0/2487.96.30.1 to 87.96.30.25487.96.30.255254
3287.96.31.0/2487.96.31.1 to 87.96.31.25487.96.31.255254
3387.96.32.0/2487.96.32.1 to 87.96.32.25487.96.32.255254
3487.96.33.0/2487.96.33.1 to 87.96.33.25487.96.33.255254
3587.96.34.0/2487.96.34.1 to 87.96.34.25487.96.34.255254
3687.96.35.0/2487.96.35.1 to 87.96.35.25487.96.35.255254
3787.96.36.0/2487.96.36.1 to 87.96.36.25487.96.36.255254
3887.96.37.0/2487.96.37.1 to 87.96.37.25487.96.37.255254
3987.96.38.0/2487.96.38.1 to 87.96.38.25487.96.38.255254
4087.96.39.0/2487.96.39.1 to 87.96.39.25487.96.39.255254
4187.96.40.0/2487.96.40.1 to 87.96.40.25487.96.40.255254
4287.96.41.0/2487.96.41.1 to 87.96.41.25487.96.41.255254
4387.96.42.0/2487.96.42.1 to 87.96.42.25487.96.42.255254
4487.96.43.0/2487.96.43.1 to 87.96.43.25487.96.43.255254
4587.96.44.0/2487.96.44.1 to 87.96.44.25487.96.44.255254
4687.96.45.0/2487.96.45.1 to 87.96.45.25487.96.45.255254
4787.96.46.0/2487.96.46.1 to 87.96.46.25487.96.46.255254
4887.96.47.0/2487.96.47.1 to 87.96.47.25487.96.47.255254
4987.96.48.0/2487.96.48.1 to 87.96.48.25487.96.48.255254
5087.96.49.0/2487.96.49.1 to 87.96.49.25487.96.49.255254
5187.96.50.0/2487.96.50.1 to 87.96.50.25487.96.50.255254
5287.96.51.0/2487.96.51.1 to 87.96.51.25487.96.51.255254
5387.96.52.0/2487.96.52.1 to 87.96.52.25487.96.52.255254
5487.96.53.0/2487.96.53.1 to 87.96.53.25487.96.53.255254
5587.96.54.0/2487.96.54.1 to 87.96.54.25487.96.54.255254
5687.96.55.0/2487.96.55.1 to 87.96.55.25487.96.55.255254
5787.96.56.0/2487.96.56.1 to 87.96.56.25487.96.56.255254
5887.96.57.0/2487.96.57.1 to 87.96.57.25487.96.57.255254
5987.96.58.0/2487.96.58.1 to 87.96.58.25487.96.58.255254
6087.96.59.0/2487.96.59.1 to 87.96.59.25487.96.59.255254
6187.96.60.0/2487.96.60.1 to 87.96.60.25487.96.60.255254
6287.96.61.0/2487.96.61.1 to 87.96.61.25487.96.61.255254
6387.96.62.0/2487.96.62.1 to 87.96.62.25487.96.62.255254
6487.96.63.0/2487.96.63.1 to 87.96.63.25487.96.63.255254
6587.96.64.0/2487.96.64.1 to 87.96.64.25487.96.64.255254
6687.96.65.0/2487.96.65.1 to 87.96.65.25487.96.65.255254
6787.96.66.0/2487.96.66.1 to 87.96.66.25487.96.66.255254
6887.96.67.0/2487.96.67.1 to 87.96.67.25487.96.67.255254
6987.96.68.0/2487.96.68.1 to 87.96.68.25487.96.68.255254
7087.96.69.0/2487.96.69.1 to 87.96.69.25487.96.69.255254
7187.96.70.0/2487.96.70.1 to 87.96.70.25487.96.70.255254
7287.96.71.0/2487.96.71.1 to 87.96.71.25487.96.71.255254
7387.96.72.0/2487.96.72.1 to 87.96.72.25487.96.72.255254
7487.96.73.0/2487.96.73.1 to 87.96.73.25487.96.73.255254
7587.96.74.0/2487.96.74.1 to 87.96.74.25487.96.74.255254
7687.96.75.0/2487.96.75.1 to 87.96.75.25487.96.75.255254
7787.96.76.0/2487.96.76.1 to 87.96.76.25487.96.76.255254
7887.96.77.0/2487.96.77.1 to 87.96.77.25487.96.77.255254
7987.96.78.0/2487.96.78.1 to 87.96.78.25487.96.78.255254
8087.96.79.0/2487.96.79.1 to 87.96.79.25487.96.79.255254
8187.96.80.0/2487.96.80.1 to 87.96.80.25487.96.80.255254
8287.96.81.0/2487.96.81.1 to 87.96.81.25487.96.81.255254
8387.96.82.0/2487.96.82.1 to 87.96.82.25487.96.82.255254
8487.96.83.0/2487.96.83.1 to 87.96.83.25487.96.83.255254
8587.96.84.0/2487.96.84.1 to 87.96.84.25487.96.84.255254
8687.96.85.0/2487.96.85.1 to 87.96.85.25487.96.85.255254
8787.96.86.0/2487.96.86.1 to 87.96.86.25487.96.86.255254
8887.96.87.0/2487.96.87.1 to 87.96.87.25487.96.87.255254
8987.96.88.0/2487.96.88.1 to 87.96.88.25487.96.88.255254
9087.96.89.0/2487.96.89.1 to 87.96.89.25487.96.89.255254
9187.96.90.0/2487.96.90.1 to 87.96.90.25487.96.90.255254
9287.96.91.0/2487.96.91.1 to 87.96.91.25487.96.91.255254
9387.96.92.0/2487.96.92.1 to 87.96.92.25487.96.92.255254
9487.96.93.0/2487.96.93.1 to 87.96.93.25487.96.93.255254
9587.96.94.0/2487.96.94.1 to 87.96.94.25487.96.94.255254
9687.96.95.0/2487.96.95.1 to 87.96.95.25487.96.95.255254
9787.96.96.0/2487.96.96.1 to 87.96.96.25487.96.96.255254
9887.96.97.0/2487.96.97.1 to 87.96.97.25487.96.97.255254
9987.96.98.0/2487.96.98.1 to 87.96.98.25487.96.98.255254
10087.96.99.0/2487.96.99.1 to 87.96.99.25487.96.99.255254
10187.96.100.0/2487.96.100.1 to 87.96.100.25487.96.100.255254
10287.96.101.0/2487.96.101.1 to 87.96.101.25487.96.101.255254
10387.96.102.0/2487.96.102.1 to 87.96.102.25487.96.102.255254
10487.96.103.0/2487.96.103.1 to 87.96.103.25487.96.103.255254
10587.96.104.0/2487.96.104.1 to 87.96.104.25487.96.104.255254
10687.96.105.0/2487.96.105.1 to 87.96.105.25487.96.105.255254
10787.96.106.0/2487.96.106.1 to 87.96.106.25487.96.106.255254
10887.96.107.0/2487.96.107.1 to 87.96.107.25487.96.107.255254
10987.96.108.0/2487.96.108.1 to 87.96.108.25487.96.108.255254
11087.96.109.0/2487.96.109.1 to 87.96.109.25487.96.109.255254
11187.96.110.0/2487.96.110.1 to 87.96.110.25487.96.110.255254
11287.96.111.0/2487.96.111.1 to 87.96.111.25487.96.111.255254
11387.96.112.0/2487.96.112.1 to 87.96.112.25487.96.112.255254
11487.96.113.0/2487.96.113.1 to 87.96.113.25487.96.113.255254
11587.96.114.0/2487.96.114.1 to 87.96.114.25487.96.114.255254
11687.96.115.0/2487.96.115.1 to 87.96.115.25487.96.115.255254
11787.96.116.0/2487.96.116.1 to 87.96.116.25487.96.116.255254
11887.96.117.0/2487.96.117.1 to 87.96.117.25487.96.117.255254
11987.96.118.0/2487.96.118.1 to 87.96.118.25487.96.118.255254
12087.96.119.0/2487.96.119.1 to 87.96.119.25487.96.119.255254
12187.96.120.0/2487.96.120.1 to 87.96.120.25487.96.120.255254
12287.96.121.0/2487.96.121.1 to 87.96.121.25487.96.121.255254
12387.96.122.0/2487.96.122.1 to 87.96.122.25487.96.122.255254
12487.96.123.0/2487.96.123.1 to 87.96.123.25487.96.123.255254
12587.96.124.0/2487.96.124.1 to 87.96.124.25487.96.124.255254
12687.96.125.0/2487.96.125.1 to 87.96.125.25487.96.125.255254
12787.96.126.0/2487.96.126.1 to 87.96.126.25487.96.126.255254
12887.96.127.0/2487.96.127.1 to 87.96.127.25487.96.127.255254
12987.96.128.0/2487.96.128.1 to 87.96.128.25487.96.128.255254
13087.96.129.0/2487.96.129.1 to 87.96.129.25487.96.129.255254
13187.96.130.0/2487.96.130.1 to 87.96.130.25487.96.130.255254
13287.96.131.0/2487.96.131.1 to 87.96.131.25487.96.131.255254
13387.96.132.0/2487.96.132.1 to 87.96.132.25487.96.132.255254
13487.96.133.0/2487.96.133.1 to 87.96.133.25487.96.133.255254
13587.96.134.0/2487.96.134.1 to 87.96.134.25487.96.134.255254
13687.96.135.0/2487.96.135.1 to 87.96.135.25487.96.135.255254
13787.96.136.0/2487.96.136.1 to 87.96.136.25487.96.136.255254
13887.96.137.0/2487.96.137.1 to 87.96.137.25487.96.137.255254
13987.96.138.0/2487.96.138.1 to 87.96.138.25487.96.138.255254
14087.96.139.0/2487.96.139.1 to 87.96.139.25487.96.139.255254
14187.96.140.0/2487.96.140.1 to 87.96.140.25487.96.140.255254
14287.96.141.0/2487.96.141.1 to 87.96.141.25487.96.141.255254
14387.96.142.0/2487.96.142.1 to 87.96.142.25487.96.142.255254
14487.96.143.0/2487.96.143.1 to 87.96.143.25487.96.143.255254
14587.96.144.0/2487.96.144.1 to 87.96.144.25487.96.144.255254
14687.96.145.0/2487.96.145.1 to 87.96.145.25487.96.145.255254
14787.96.146.0/2487.96.146.1 to 87.96.146.25487.96.146.255254
14887.96.147.0/2487.96.147.1 to 87.96.147.25487.96.147.255254
14987.96.148.0/2487.96.148.1 to 87.96.148.25487.96.148.255254
15087.96.149.0/2487.96.149.1 to 87.96.149.25487.96.149.255254
15187.96.150.0/2487.96.150.1 to 87.96.150.25487.96.150.255254
15287.96.151.0/2487.96.151.1 to 87.96.151.25487.96.151.255254
15387.96.152.0/2487.96.152.1 to 87.96.152.25487.96.152.255254
15487.96.153.0/2487.96.153.1 to 87.96.153.25487.96.153.255254
15587.96.154.0/2487.96.154.1 to 87.96.154.25487.96.154.255254
15687.96.155.0/2487.96.155.1 to 87.96.155.25487.96.155.255254
15787.96.156.0/2487.96.156.1 to 87.96.156.25487.96.156.255254
15887.96.157.0/2487.96.157.1 to 87.96.157.25487.96.157.255254
15987.96.158.0/2487.96.158.1 to 87.96.158.25487.96.158.255254
16087.96.159.0/2487.96.159.1 to 87.96.159.25487.96.159.255254
16187.96.160.0/2487.96.160.1 to 87.96.160.25487.96.160.255254
16287.96.161.0/2487.96.161.1 to 87.96.161.25487.96.161.255254
16387.96.162.0/2487.96.162.1 to 87.96.162.25487.96.162.255254
16487.96.163.0/2487.96.163.1 to 87.96.163.25487.96.163.255254
16587.96.164.0/2487.96.164.1 to 87.96.164.25487.96.164.255254
16687.96.165.0/2487.96.165.1 to 87.96.165.25487.96.165.255254
16787.96.166.0/2487.96.166.1 to 87.96.166.25487.96.166.255254
16887.96.167.0/2487.96.167.1 to 87.96.167.25487.96.167.255254
16987.96.168.0/2487.96.168.1 to 87.96.168.25487.96.168.255254
17087.96.169.0/2487.96.169.1 to 87.96.169.25487.96.169.255254
17187.96.170.0/2487.96.170.1 to 87.96.170.25487.96.170.255254
17287.96.171.0/2487.96.171.1 to 87.96.171.25487.96.171.255254
17387.96.172.0/2487.96.172.1 to 87.96.172.25487.96.172.255254
17487.96.173.0/2487.96.173.1 to 87.96.173.25487.96.173.255254
17587.96.174.0/2487.96.174.1 to 87.96.174.25487.96.174.255254
17687.96.175.0/2487.96.175.1 to 87.96.175.25487.96.175.255254
17787.96.176.0/2487.96.176.1 to 87.96.176.25487.96.176.255254
17887.96.177.0/2487.96.177.1 to 87.96.177.25487.96.177.255254
17987.96.178.0/2487.96.178.1 to 87.96.178.25487.96.178.255254
18087.96.179.0/2487.96.179.1 to 87.96.179.25487.96.179.255254
18187.96.180.0/2487.96.180.1 to 87.96.180.25487.96.180.255254
18287.96.181.0/2487.96.181.1 to 87.96.181.25487.96.181.255254
18387.96.182.0/2487.96.182.1 to 87.96.182.25487.96.182.255254
18487.96.183.0/2487.96.183.1 to 87.96.183.25487.96.183.255254
18587.96.184.0/2487.96.184.1 to 87.96.184.25487.96.184.255254
18687.96.185.0/2487.96.185.1 to 87.96.185.25487.96.185.255254
18787.96.186.0/2487.96.186.1 to 87.96.186.25487.96.186.255254
18887.96.187.0/2487.96.187.1 to 87.96.187.25487.96.187.255254
18987.96.188.0/2487.96.188.1 to 87.96.188.25487.96.188.255254
19087.96.189.0/2487.96.189.1 to 87.96.189.25487.96.189.255254
19187.96.190.0/2487.96.190.1 to 87.96.190.25487.96.190.255254
19287.96.191.0/2487.96.191.1 to 87.96.191.25487.96.191.255254
19387.96.192.0/2487.96.192.1 to 87.96.192.25487.96.192.255254
19487.96.193.0/2487.96.193.1 to 87.96.193.25487.96.193.255254
19587.96.194.0/2487.96.194.1 to 87.96.194.25487.96.194.255254
19687.96.195.0/2487.96.195.1 to 87.96.195.25487.96.195.255254
19787.96.196.0/2487.96.196.1 to 87.96.196.25487.96.196.255254
19887.96.197.0/2487.96.197.1 to 87.96.197.25487.96.197.255254
19987.96.198.0/2487.96.198.1 to 87.96.198.25487.96.198.255254
20087.96.199.0/2487.96.199.1 to 87.96.199.25487.96.199.255254
20187.96.200.0/2487.96.200.1 to 87.96.200.25487.96.200.255254
20287.96.201.0/2487.96.201.1 to 87.96.201.25487.96.201.255254
20387.96.202.0/2487.96.202.1 to 87.96.202.25487.96.202.255254
20487.96.203.0/2487.96.203.1 to 87.96.203.25487.96.203.255254
20587.96.204.0/2487.96.204.1 to 87.96.204.25487.96.204.255254
20687.96.205.0/2487.96.205.1 to 87.96.205.25487.96.205.255254
20787.96.206.0/2487.96.206.1 to 87.96.206.25487.96.206.255254
20887.96.207.0/2487.96.207.1 to 87.96.207.25487.96.207.255254
20987.96.208.0/2487.96.208.1 to 87.96.208.25487.96.208.255254
21087.96.209.0/2487.96.209.1 to 87.96.209.25487.96.209.255254
21187.96.210.0/2487.96.210.1 to 87.96.210.25487.96.210.255254
21287.96.211.0/2487.96.211.1 to 87.96.211.25487.96.211.255254
21387.96.212.0/2487.96.212.1 to 87.96.212.25487.96.212.255254
21487.96.213.0/2487.96.213.1 to 87.96.213.25487.96.213.255254
21587.96.214.0/2487.96.214.1 to 87.96.214.25487.96.214.255254
21687.96.215.0/2487.96.215.1 to 87.96.215.25487.96.215.255254
21787.96.216.0/2487.96.216.1 to 87.96.216.25487.96.216.255254
21887.96.217.0/2487.96.217.1 to 87.96.217.25487.96.217.255254
21987.96.218.0/2487.96.218.1 to 87.96.218.25487.96.218.255254
22087.96.219.0/2487.96.219.1 to 87.96.219.25487.96.219.255254
22187.96.220.0/2487.96.220.1 to 87.96.220.25487.96.220.255254
22287.96.221.0/2487.96.221.1 to 87.96.221.25487.96.221.255254
22387.96.222.0/2487.96.222.1 to 87.96.222.25487.96.222.255254
22487.96.223.0/2487.96.223.1 to 87.96.223.25487.96.223.255254
22587.96.224.0/2487.96.224.1 to 87.96.224.25487.96.224.255254
22687.96.225.0/2487.96.225.1 to 87.96.225.25487.96.225.255254
22787.96.226.0/2487.96.226.1 to 87.96.226.25487.96.226.255254
22887.96.227.0/2487.96.227.1 to 87.96.227.25487.96.227.255254
22987.96.228.0/2487.96.228.1 to 87.96.228.25487.96.228.255254
23087.96.229.0/2487.96.229.1 to 87.96.229.25487.96.229.255254
23187.96.230.0/2487.96.230.1 to 87.96.230.25487.96.230.255254
23287.96.231.0/2487.96.231.1 to 87.96.231.25487.96.231.255254
23387.96.232.0/2487.96.232.1 to 87.96.232.25487.96.232.255254
23487.96.233.0/2487.96.233.1 to 87.96.233.25487.96.233.255254
23587.96.234.0/2487.96.234.1 to 87.96.234.25487.96.234.255254
23687.96.235.0/2487.96.235.1 to 87.96.235.25487.96.235.255254
23787.96.236.0/2487.96.236.1 to 87.96.236.25487.96.236.255254
23887.96.237.0/2487.96.237.1 to 87.96.237.25487.96.237.255254
23987.96.238.0/2487.96.238.1 to 87.96.238.25487.96.238.255254
24087.96.239.0/2487.96.239.1 to 87.96.239.25487.96.239.255254
24187.96.240.0/2487.96.240.1 to 87.96.240.25487.96.240.255254
24287.96.241.0/2487.96.241.1 to 87.96.241.25487.96.241.255254
24387.96.242.0/2487.96.242.1 to 87.96.242.25487.96.242.255254
24487.96.243.0/2487.96.243.1 to 87.96.243.25487.96.243.255254
24587.96.244.0/2487.96.244.1 to 87.96.244.25487.96.244.255254
24687.96.245.0/2487.96.245.1 to 87.96.245.25487.96.245.255254
24787.96.246.0/2487.96.246.1 to 87.96.246.25487.96.246.255254
24887.96.247.0/2487.96.247.1 to 87.96.247.25487.96.247.255254
24987.96.248.0/2487.96.248.1 to 87.96.248.25487.96.248.255254
25087.96.249.0/2487.96.249.1 to 87.96.249.25487.96.249.255254
25187.96.250.0/2487.96.250.1 to 87.96.250.25487.96.250.255254
25287.96.251.0/2487.96.251.1 to 87.96.251.25487.96.251.255254
25387.96.252.0/2487.96.252.1 to 87.96.252.25487.96.252.255254
25487.96.253.0/2487.96.253.1 to 87.96.253.25487.96.253.255254
25587.96.254.0/2487.96.254.1 to 87.96.254.25487.96.254.255254
25687.96.255.0/2487.96.255.1 to 87.96.255.25487.96.255.255254

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.