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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.

Network87.40.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
87.40.0.0
Broadcast address
87.47.255.255
First usable
87.40.0.1
Last usable
87.47.255.254
Usable hosts
524,286 (524,288 less the network and broadcast addresses)
Subnet mask
255.248.0.0
Wildcard mask
0.7.255.255 (Cisco ACLs, OSPF)
Prefix length
/13
Type
Public public
Old class
A (default /8)
As numbers
Hex 57280000 · Integer 1462239232 to 1462763519
Reverse DNS zones
40.87.in-addr.arpa
41.87.in-addr.arpa
42.87.in-addr.arpa
43.87.in-addr.arpa
44.87.in-addr.arpa
45.87.in-addr.arpa
46.87.in-addr.arpa
47.87.in-addr.arpa
/13 is not on a 8-bit boundary, so it takes 8 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01010111.00101000.00000000.0000000087.40.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network01010111.00101000.00000000.0000000087.40.0.0
Broadcast01010111.00101111.11111111.1111111187.47.255.255
Split into smaller subnets/23
/14 (2)/15 (4)/16 (8)/17 (16)/18 (32)/19 (64)/20 (128)/21 (256)/22 (512)/23 (1,024)/24 (2,048)/25 (4,096)

87.40.0.0/13 makes 1,024 subnets of /23; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
187.40.0.0/2387.40.0.1 to 87.40.1.25487.40.1.255510
287.40.2.0/2387.40.2.1 to 87.40.3.25487.40.3.255510
387.40.4.0/2387.40.4.1 to 87.40.5.25487.40.5.255510
487.40.6.0/2387.40.6.1 to 87.40.7.25487.40.7.255510
587.40.8.0/2387.40.8.1 to 87.40.9.25487.40.9.255510
687.40.10.0/2387.40.10.1 to 87.40.11.25487.40.11.255510
787.40.12.0/2387.40.12.1 to 87.40.13.25487.40.13.255510
887.40.14.0/2387.40.14.1 to 87.40.15.25487.40.15.255510
987.40.16.0/2387.40.16.1 to 87.40.17.25487.40.17.255510
1087.40.18.0/2387.40.18.1 to 87.40.19.25487.40.19.255510
1187.40.20.0/2387.40.20.1 to 87.40.21.25487.40.21.255510
1287.40.22.0/2387.40.22.1 to 87.40.23.25487.40.23.255510
1387.40.24.0/2387.40.24.1 to 87.40.25.25487.40.25.255510
1487.40.26.0/2387.40.26.1 to 87.40.27.25487.40.27.255510
1587.40.28.0/2387.40.28.1 to 87.40.29.25487.40.29.255510
1687.40.30.0/2387.40.30.1 to 87.40.31.25487.40.31.255510
1787.40.32.0/2387.40.32.1 to 87.40.33.25487.40.33.255510
1887.40.34.0/2387.40.34.1 to 87.40.35.25487.40.35.255510
1987.40.36.0/2387.40.36.1 to 87.40.37.25487.40.37.255510
2087.40.38.0/2387.40.38.1 to 87.40.39.25487.40.39.255510
2187.40.40.0/2387.40.40.1 to 87.40.41.25487.40.41.255510
2287.40.42.0/2387.40.42.1 to 87.40.43.25487.40.43.255510
2387.40.44.0/2387.40.44.1 to 87.40.45.25487.40.45.255510
2487.40.46.0/2387.40.46.1 to 87.40.47.25487.40.47.255510
2587.40.48.0/2387.40.48.1 to 87.40.49.25487.40.49.255510
2687.40.50.0/2387.40.50.1 to 87.40.51.25487.40.51.255510
2787.40.52.0/2387.40.52.1 to 87.40.53.25487.40.53.255510
2887.40.54.0/2387.40.54.1 to 87.40.55.25487.40.55.255510
2987.40.56.0/2387.40.56.1 to 87.40.57.25487.40.57.255510
3087.40.58.0/2387.40.58.1 to 87.40.59.25487.40.59.255510
3187.40.60.0/2387.40.60.1 to 87.40.61.25487.40.61.255510
3287.40.62.0/2387.40.62.1 to 87.40.63.25487.40.63.255510
3387.40.64.0/2387.40.64.1 to 87.40.65.25487.40.65.255510
3487.40.66.0/2387.40.66.1 to 87.40.67.25487.40.67.255510
3587.40.68.0/2387.40.68.1 to 87.40.69.25487.40.69.255510
3687.40.70.0/2387.40.70.1 to 87.40.71.25487.40.71.255510
3787.40.72.0/2387.40.72.1 to 87.40.73.25487.40.73.255510
3887.40.74.0/2387.40.74.1 to 87.40.75.25487.40.75.255510
3987.40.76.0/2387.40.76.1 to 87.40.77.25487.40.77.255510
4087.40.78.0/2387.40.78.1 to 87.40.79.25487.40.79.255510
4187.40.80.0/2387.40.80.1 to 87.40.81.25487.40.81.255510
4287.40.82.0/2387.40.82.1 to 87.40.83.25487.40.83.255510
4387.40.84.0/2387.40.84.1 to 87.40.85.25487.40.85.255510
4487.40.86.0/2387.40.86.1 to 87.40.87.25487.40.87.255510
4587.40.88.0/2387.40.88.1 to 87.40.89.25487.40.89.255510
4687.40.90.0/2387.40.90.1 to 87.40.91.25487.40.91.255510
4787.40.92.0/2387.40.92.1 to 87.40.93.25487.40.93.255510
4887.40.94.0/2387.40.94.1 to 87.40.95.25487.40.95.255510
4987.40.96.0/2387.40.96.1 to 87.40.97.25487.40.97.255510
5087.40.98.0/2387.40.98.1 to 87.40.99.25487.40.99.255510
5187.40.100.0/2387.40.100.1 to 87.40.101.25487.40.101.255510
5287.40.102.0/2387.40.102.1 to 87.40.103.25487.40.103.255510
5387.40.104.0/2387.40.104.1 to 87.40.105.25487.40.105.255510
5487.40.106.0/2387.40.106.1 to 87.40.107.25487.40.107.255510
5587.40.108.0/2387.40.108.1 to 87.40.109.25487.40.109.255510
5687.40.110.0/2387.40.110.1 to 87.40.111.25487.40.111.255510
5787.40.112.0/2387.40.112.1 to 87.40.113.25487.40.113.255510
5887.40.114.0/2387.40.114.1 to 87.40.115.25487.40.115.255510
5987.40.116.0/2387.40.116.1 to 87.40.117.25487.40.117.255510
6087.40.118.0/2387.40.118.1 to 87.40.119.25487.40.119.255510
6187.40.120.0/2387.40.120.1 to 87.40.121.25487.40.121.255510
6287.40.122.0/2387.40.122.1 to 87.40.123.25487.40.123.255510
6387.40.124.0/2387.40.124.1 to 87.40.125.25487.40.125.255510
6487.40.126.0/2387.40.126.1 to 87.40.127.25487.40.127.255510
6587.40.128.0/2387.40.128.1 to 87.40.129.25487.40.129.255510
6687.40.130.0/2387.40.130.1 to 87.40.131.25487.40.131.255510
6787.40.132.0/2387.40.132.1 to 87.40.133.25487.40.133.255510
6887.40.134.0/2387.40.134.1 to 87.40.135.25487.40.135.255510
6987.40.136.0/2387.40.136.1 to 87.40.137.25487.40.137.255510
7087.40.138.0/2387.40.138.1 to 87.40.139.25487.40.139.255510
7187.40.140.0/2387.40.140.1 to 87.40.141.25487.40.141.255510
7287.40.142.0/2387.40.142.1 to 87.40.143.25487.40.143.255510
7387.40.144.0/2387.40.144.1 to 87.40.145.25487.40.145.255510
7487.40.146.0/2387.40.146.1 to 87.40.147.25487.40.147.255510
7587.40.148.0/2387.40.148.1 to 87.40.149.25487.40.149.255510
7687.40.150.0/2387.40.150.1 to 87.40.151.25487.40.151.255510
7787.40.152.0/2387.40.152.1 to 87.40.153.25487.40.153.255510
7887.40.154.0/2387.40.154.1 to 87.40.155.25487.40.155.255510
7987.40.156.0/2387.40.156.1 to 87.40.157.25487.40.157.255510
8087.40.158.0/2387.40.158.1 to 87.40.159.25487.40.159.255510
8187.40.160.0/2387.40.160.1 to 87.40.161.25487.40.161.255510
8287.40.162.0/2387.40.162.1 to 87.40.163.25487.40.163.255510
8387.40.164.0/2387.40.164.1 to 87.40.165.25487.40.165.255510
8487.40.166.0/2387.40.166.1 to 87.40.167.25487.40.167.255510
8587.40.168.0/2387.40.168.1 to 87.40.169.25487.40.169.255510
8687.40.170.0/2387.40.170.1 to 87.40.171.25487.40.171.255510
8787.40.172.0/2387.40.172.1 to 87.40.173.25487.40.173.255510
8887.40.174.0/2387.40.174.1 to 87.40.175.25487.40.175.255510
8987.40.176.0/2387.40.176.1 to 87.40.177.25487.40.177.255510
9087.40.178.0/2387.40.178.1 to 87.40.179.25487.40.179.255510
9187.40.180.0/2387.40.180.1 to 87.40.181.25487.40.181.255510
9287.40.182.0/2387.40.182.1 to 87.40.183.25487.40.183.255510
9387.40.184.0/2387.40.184.1 to 87.40.185.25487.40.185.255510
9487.40.186.0/2387.40.186.1 to 87.40.187.25487.40.187.255510
9587.40.188.0/2387.40.188.1 to 87.40.189.25487.40.189.255510
9687.40.190.0/2387.40.190.1 to 87.40.191.25487.40.191.255510
9787.40.192.0/2387.40.192.1 to 87.40.193.25487.40.193.255510
9887.40.194.0/2387.40.194.1 to 87.40.195.25487.40.195.255510
9987.40.196.0/2387.40.196.1 to 87.40.197.25487.40.197.255510
10087.40.198.0/2387.40.198.1 to 87.40.199.25487.40.199.255510
10187.40.200.0/2387.40.200.1 to 87.40.201.25487.40.201.255510
10287.40.202.0/2387.40.202.1 to 87.40.203.25487.40.203.255510
10387.40.204.0/2387.40.204.1 to 87.40.205.25487.40.205.255510
10487.40.206.0/2387.40.206.1 to 87.40.207.25487.40.207.255510
10587.40.208.0/2387.40.208.1 to 87.40.209.25487.40.209.255510
10687.40.210.0/2387.40.210.1 to 87.40.211.25487.40.211.255510
10787.40.212.0/2387.40.212.1 to 87.40.213.25487.40.213.255510
10887.40.214.0/2387.40.214.1 to 87.40.215.25487.40.215.255510
10987.40.216.0/2387.40.216.1 to 87.40.217.25487.40.217.255510
11087.40.218.0/2387.40.218.1 to 87.40.219.25487.40.219.255510
11187.40.220.0/2387.40.220.1 to 87.40.221.25487.40.221.255510
11287.40.222.0/2387.40.222.1 to 87.40.223.25487.40.223.255510
11387.40.224.0/2387.40.224.1 to 87.40.225.25487.40.225.255510
11487.40.226.0/2387.40.226.1 to 87.40.227.25487.40.227.255510
11587.40.228.0/2387.40.228.1 to 87.40.229.25487.40.229.255510
11687.40.230.0/2387.40.230.1 to 87.40.231.25487.40.231.255510
11787.40.232.0/2387.40.232.1 to 87.40.233.25487.40.233.255510
11887.40.234.0/2387.40.234.1 to 87.40.235.25487.40.235.255510
11987.40.236.0/2387.40.236.1 to 87.40.237.25487.40.237.255510
12087.40.238.0/2387.40.238.1 to 87.40.239.25487.40.239.255510
12187.40.240.0/2387.40.240.1 to 87.40.241.25487.40.241.255510
12287.40.242.0/2387.40.242.1 to 87.40.243.25487.40.243.255510
12387.40.244.0/2387.40.244.1 to 87.40.245.25487.40.245.255510
12487.40.246.0/2387.40.246.1 to 87.40.247.25487.40.247.255510
12587.40.248.0/2387.40.248.1 to 87.40.249.25487.40.249.255510
12687.40.250.0/2387.40.250.1 to 87.40.251.25487.40.251.255510
12787.40.252.0/2387.40.252.1 to 87.40.253.25487.40.253.255510
12887.40.254.0/2387.40.254.1 to 87.40.255.25487.40.255.255510
12987.41.0.0/2387.41.0.1 to 87.41.1.25487.41.1.255510
13087.41.2.0/2387.41.2.1 to 87.41.3.25487.41.3.255510
13187.41.4.0/2387.41.4.1 to 87.41.5.25487.41.5.255510
13287.41.6.0/2387.41.6.1 to 87.41.7.25487.41.7.255510
13387.41.8.0/2387.41.8.1 to 87.41.9.25487.41.9.255510
13487.41.10.0/2387.41.10.1 to 87.41.11.25487.41.11.255510
13587.41.12.0/2387.41.12.1 to 87.41.13.25487.41.13.255510
13687.41.14.0/2387.41.14.1 to 87.41.15.25487.41.15.255510
13787.41.16.0/2387.41.16.1 to 87.41.17.25487.41.17.255510
13887.41.18.0/2387.41.18.1 to 87.41.19.25487.41.19.255510
13987.41.20.0/2387.41.20.1 to 87.41.21.25487.41.21.255510
14087.41.22.0/2387.41.22.1 to 87.41.23.25487.41.23.255510
14187.41.24.0/2387.41.24.1 to 87.41.25.25487.41.25.255510
14287.41.26.0/2387.41.26.1 to 87.41.27.25487.41.27.255510
14387.41.28.0/2387.41.28.1 to 87.41.29.25487.41.29.255510
14487.41.30.0/2387.41.30.1 to 87.41.31.25487.41.31.255510
14587.41.32.0/2387.41.32.1 to 87.41.33.25487.41.33.255510
14687.41.34.0/2387.41.34.1 to 87.41.35.25487.41.35.255510
14787.41.36.0/2387.41.36.1 to 87.41.37.25487.41.37.255510
14887.41.38.0/2387.41.38.1 to 87.41.39.25487.41.39.255510
14987.41.40.0/2387.41.40.1 to 87.41.41.25487.41.41.255510
15087.41.42.0/2387.41.42.1 to 87.41.43.25487.41.43.255510
15187.41.44.0/2387.41.44.1 to 87.41.45.25487.41.45.255510
15287.41.46.0/2387.41.46.1 to 87.41.47.25487.41.47.255510
15387.41.48.0/2387.41.48.1 to 87.41.49.25487.41.49.255510
15487.41.50.0/2387.41.50.1 to 87.41.51.25487.41.51.255510
15587.41.52.0/2387.41.52.1 to 87.41.53.25487.41.53.255510
15687.41.54.0/2387.41.54.1 to 87.41.55.25487.41.55.255510
15787.41.56.0/2387.41.56.1 to 87.41.57.25487.41.57.255510
15887.41.58.0/2387.41.58.1 to 87.41.59.25487.41.59.255510
15987.41.60.0/2387.41.60.1 to 87.41.61.25487.41.61.255510
16087.41.62.0/2387.41.62.1 to 87.41.63.25487.41.63.255510
16187.41.64.0/2387.41.64.1 to 87.41.65.25487.41.65.255510
16287.41.66.0/2387.41.66.1 to 87.41.67.25487.41.67.255510
16387.41.68.0/2387.41.68.1 to 87.41.69.25487.41.69.255510
16487.41.70.0/2387.41.70.1 to 87.41.71.25487.41.71.255510
16587.41.72.0/2387.41.72.1 to 87.41.73.25487.41.73.255510
16687.41.74.0/2387.41.74.1 to 87.41.75.25487.41.75.255510
16787.41.76.0/2387.41.76.1 to 87.41.77.25487.41.77.255510
16887.41.78.0/2387.41.78.1 to 87.41.79.25487.41.79.255510
16987.41.80.0/2387.41.80.1 to 87.41.81.25487.41.81.255510
17087.41.82.0/2387.41.82.1 to 87.41.83.25487.41.83.255510
17187.41.84.0/2387.41.84.1 to 87.41.85.25487.41.85.255510
17287.41.86.0/2387.41.86.1 to 87.41.87.25487.41.87.255510
17387.41.88.0/2387.41.88.1 to 87.41.89.25487.41.89.255510
17487.41.90.0/2387.41.90.1 to 87.41.91.25487.41.91.255510
17587.41.92.0/2387.41.92.1 to 87.41.93.25487.41.93.255510
17687.41.94.0/2387.41.94.1 to 87.41.95.25487.41.95.255510
17787.41.96.0/2387.41.96.1 to 87.41.97.25487.41.97.255510
17887.41.98.0/2387.41.98.1 to 87.41.99.25487.41.99.255510
17987.41.100.0/2387.41.100.1 to 87.41.101.25487.41.101.255510
18087.41.102.0/2387.41.102.1 to 87.41.103.25487.41.103.255510
18187.41.104.0/2387.41.104.1 to 87.41.105.25487.41.105.255510
18287.41.106.0/2387.41.106.1 to 87.41.107.25487.41.107.255510
18387.41.108.0/2387.41.108.1 to 87.41.109.25487.41.109.255510
18487.41.110.0/2387.41.110.1 to 87.41.111.25487.41.111.255510
18587.41.112.0/2387.41.112.1 to 87.41.113.25487.41.113.255510
18687.41.114.0/2387.41.114.1 to 87.41.115.25487.41.115.255510
18787.41.116.0/2387.41.116.1 to 87.41.117.25487.41.117.255510
18887.41.118.0/2387.41.118.1 to 87.41.119.25487.41.119.255510
18987.41.120.0/2387.41.120.1 to 87.41.121.25487.41.121.255510
19087.41.122.0/2387.41.122.1 to 87.41.123.25487.41.123.255510
19187.41.124.0/2387.41.124.1 to 87.41.125.25487.41.125.255510
19287.41.126.0/2387.41.126.1 to 87.41.127.25487.41.127.255510
19387.41.128.0/2387.41.128.1 to 87.41.129.25487.41.129.255510
19487.41.130.0/2387.41.130.1 to 87.41.131.25487.41.131.255510
19587.41.132.0/2387.41.132.1 to 87.41.133.25487.41.133.255510
19687.41.134.0/2387.41.134.1 to 87.41.135.25487.41.135.255510
19787.41.136.0/2387.41.136.1 to 87.41.137.25487.41.137.255510
19887.41.138.0/2387.41.138.1 to 87.41.139.25487.41.139.255510
19987.41.140.0/2387.41.140.1 to 87.41.141.25487.41.141.255510
20087.41.142.0/2387.41.142.1 to 87.41.143.25487.41.143.255510
20187.41.144.0/2387.41.144.1 to 87.41.145.25487.41.145.255510
20287.41.146.0/2387.41.146.1 to 87.41.147.25487.41.147.255510
20387.41.148.0/2387.41.148.1 to 87.41.149.25487.41.149.255510
20487.41.150.0/2387.41.150.1 to 87.41.151.25487.41.151.255510
20587.41.152.0/2387.41.152.1 to 87.41.153.25487.41.153.255510
20687.41.154.0/2387.41.154.1 to 87.41.155.25487.41.155.255510
20787.41.156.0/2387.41.156.1 to 87.41.157.25487.41.157.255510
20887.41.158.0/2387.41.158.1 to 87.41.159.25487.41.159.255510
20987.41.160.0/2387.41.160.1 to 87.41.161.25487.41.161.255510
21087.41.162.0/2387.41.162.1 to 87.41.163.25487.41.163.255510
21187.41.164.0/2387.41.164.1 to 87.41.165.25487.41.165.255510
21287.41.166.0/2387.41.166.1 to 87.41.167.25487.41.167.255510
21387.41.168.0/2387.41.168.1 to 87.41.169.25487.41.169.255510
21487.41.170.0/2387.41.170.1 to 87.41.171.25487.41.171.255510
21587.41.172.0/2387.41.172.1 to 87.41.173.25487.41.173.255510
21687.41.174.0/2387.41.174.1 to 87.41.175.25487.41.175.255510
21787.41.176.0/2387.41.176.1 to 87.41.177.25487.41.177.255510
21887.41.178.0/2387.41.178.1 to 87.41.179.25487.41.179.255510
21987.41.180.0/2387.41.180.1 to 87.41.181.25487.41.181.255510
22087.41.182.0/2387.41.182.1 to 87.41.183.25487.41.183.255510
22187.41.184.0/2387.41.184.1 to 87.41.185.25487.41.185.255510
22287.41.186.0/2387.41.186.1 to 87.41.187.25487.41.187.255510
22387.41.188.0/2387.41.188.1 to 87.41.189.25487.41.189.255510
22487.41.190.0/2387.41.190.1 to 87.41.191.25487.41.191.255510
22587.41.192.0/2387.41.192.1 to 87.41.193.25487.41.193.255510
22687.41.194.0/2387.41.194.1 to 87.41.195.25487.41.195.255510
22787.41.196.0/2387.41.196.1 to 87.41.197.25487.41.197.255510
22887.41.198.0/2387.41.198.1 to 87.41.199.25487.41.199.255510
22987.41.200.0/2387.41.200.1 to 87.41.201.25487.41.201.255510
23087.41.202.0/2387.41.202.1 to 87.41.203.25487.41.203.255510
23187.41.204.0/2387.41.204.1 to 87.41.205.25487.41.205.255510
23287.41.206.0/2387.41.206.1 to 87.41.207.25487.41.207.255510
23387.41.208.0/2387.41.208.1 to 87.41.209.25487.41.209.255510
23487.41.210.0/2387.41.210.1 to 87.41.211.25487.41.211.255510
23587.41.212.0/2387.41.212.1 to 87.41.213.25487.41.213.255510
23687.41.214.0/2387.41.214.1 to 87.41.215.25487.41.215.255510
23787.41.216.0/2387.41.216.1 to 87.41.217.25487.41.217.255510
23887.41.218.0/2387.41.218.1 to 87.41.219.25487.41.219.255510
23987.41.220.0/2387.41.220.1 to 87.41.221.25487.41.221.255510
24087.41.222.0/2387.41.222.1 to 87.41.223.25487.41.223.255510
24187.41.224.0/2387.41.224.1 to 87.41.225.25487.41.225.255510
24287.41.226.0/2387.41.226.1 to 87.41.227.25487.41.227.255510
24387.41.228.0/2387.41.228.1 to 87.41.229.25487.41.229.255510
24487.41.230.0/2387.41.230.1 to 87.41.231.25487.41.231.255510
24587.41.232.0/2387.41.232.1 to 87.41.233.25487.41.233.255510
24687.41.234.0/2387.41.234.1 to 87.41.235.25487.41.235.255510
24787.41.236.0/2387.41.236.1 to 87.41.237.25487.41.237.255510
24887.41.238.0/2387.41.238.1 to 87.41.239.25487.41.239.255510
24987.41.240.0/2387.41.240.1 to 87.41.241.25487.41.241.255510
25087.41.242.0/2387.41.242.1 to 87.41.243.25487.41.243.255510
25187.41.244.0/2387.41.244.1 to 87.41.245.25487.41.245.255510
25287.41.246.0/2387.41.246.1 to 87.41.247.25487.41.247.255510
25387.41.248.0/2387.41.248.1 to 87.41.249.25487.41.249.255510
25487.41.250.0/2387.41.250.1 to 87.41.251.25487.41.251.255510
25587.41.252.0/2387.41.252.1 to 87.41.253.25487.41.253.255510
25687.41.254.0/2387.41.254.1 to 87.41.255.25487.41.255.255510

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.