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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.

Network7.0.0.0/11
Usable hosts2,097,150
Subnet mask255.224.0.0
Addresses2,097,152
Network address
7.0.0.0
Broadcast address
7.31.255.255
First usable
7.0.0.1
Last usable
7.31.255.254
Usable hosts
2,097,150 (2,097,152 less the network and broadcast addresses)
Subnet mask
255.224.0.0
Wildcard mask
0.31.255.255 (Cisco ACLs, OSPF)
Prefix length
/11
Type
Public public
Old class
A (default /8)
As numbers
Hex 07000000 · Integer 117440512 to 119537663
Reverse DNS zones
0.7.in-addr.arpa
1.7.in-addr.arpa
2.7.in-addr.arpa
3.7.in-addr.arpa
4.7.in-addr.arpa
5.7.in-addr.arpa
6.7.in-addr.arpa
7.7.in-addr.arpa
8.7.in-addr.arpa
9.7.in-addr.arpa
10.7.in-addr.arpa
11.7.in-addr.arpa
12.7.in-addr.arpa
13.7.in-addr.arpa
14.7.in-addr.arpa
15.7.in-addr.arpa
and 16 more
/11 is not on a 8-bit boundary, so it takes 32 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00000111.00000000.00000000.000000007.0.0.0
Subnet mask11111111.11100000.00000000.00000000255.224.0.0
Network00000111.00000000.00000000.000000007.0.0.0
Broadcast00000111.00011111.11111111.111111117.31.255.255
Split into smaller subnets/23
/12 (2)/13 (4)/14 (8)/15 (16)/16 (32)/17 (64)/18 (128)/19 (256)/20 (512)/21 (1,024)/22 (2,048)/23 (4,096)

7.0.0.0/11 makes 4,096 subnets of /23; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
17.0.0.0/237.0.0.1 to 7.0.1.2547.0.1.255510
27.0.2.0/237.0.2.1 to 7.0.3.2547.0.3.255510
37.0.4.0/237.0.4.1 to 7.0.5.2547.0.5.255510
47.0.6.0/237.0.6.1 to 7.0.7.2547.0.7.255510
57.0.8.0/237.0.8.1 to 7.0.9.2547.0.9.255510
67.0.10.0/237.0.10.1 to 7.0.11.2547.0.11.255510
77.0.12.0/237.0.12.1 to 7.0.13.2547.0.13.255510
87.0.14.0/237.0.14.1 to 7.0.15.2547.0.15.255510
97.0.16.0/237.0.16.1 to 7.0.17.2547.0.17.255510
107.0.18.0/237.0.18.1 to 7.0.19.2547.0.19.255510
117.0.20.0/237.0.20.1 to 7.0.21.2547.0.21.255510
127.0.22.0/237.0.22.1 to 7.0.23.2547.0.23.255510
137.0.24.0/237.0.24.1 to 7.0.25.2547.0.25.255510
147.0.26.0/237.0.26.1 to 7.0.27.2547.0.27.255510
157.0.28.0/237.0.28.1 to 7.0.29.2547.0.29.255510
167.0.30.0/237.0.30.1 to 7.0.31.2547.0.31.255510
177.0.32.0/237.0.32.1 to 7.0.33.2547.0.33.255510
187.0.34.0/237.0.34.1 to 7.0.35.2547.0.35.255510
197.0.36.0/237.0.36.1 to 7.0.37.2547.0.37.255510
207.0.38.0/237.0.38.1 to 7.0.39.2547.0.39.255510
217.0.40.0/237.0.40.1 to 7.0.41.2547.0.41.255510
227.0.42.0/237.0.42.1 to 7.0.43.2547.0.43.255510
237.0.44.0/237.0.44.1 to 7.0.45.2547.0.45.255510
247.0.46.0/237.0.46.1 to 7.0.47.2547.0.47.255510
257.0.48.0/237.0.48.1 to 7.0.49.2547.0.49.255510
267.0.50.0/237.0.50.1 to 7.0.51.2547.0.51.255510
277.0.52.0/237.0.52.1 to 7.0.53.2547.0.53.255510
287.0.54.0/237.0.54.1 to 7.0.55.2547.0.55.255510
297.0.56.0/237.0.56.1 to 7.0.57.2547.0.57.255510
307.0.58.0/237.0.58.1 to 7.0.59.2547.0.59.255510
317.0.60.0/237.0.60.1 to 7.0.61.2547.0.61.255510
327.0.62.0/237.0.62.1 to 7.0.63.2547.0.63.255510
337.0.64.0/237.0.64.1 to 7.0.65.2547.0.65.255510
347.0.66.0/237.0.66.1 to 7.0.67.2547.0.67.255510
357.0.68.0/237.0.68.1 to 7.0.69.2547.0.69.255510
367.0.70.0/237.0.70.1 to 7.0.71.2547.0.71.255510
377.0.72.0/237.0.72.1 to 7.0.73.2547.0.73.255510
387.0.74.0/237.0.74.1 to 7.0.75.2547.0.75.255510
397.0.76.0/237.0.76.1 to 7.0.77.2547.0.77.255510
407.0.78.0/237.0.78.1 to 7.0.79.2547.0.79.255510
417.0.80.0/237.0.80.1 to 7.0.81.2547.0.81.255510
427.0.82.0/237.0.82.1 to 7.0.83.2547.0.83.255510
437.0.84.0/237.0.84.1 to 7.0.85.2547.0.85.255510
447.0.86.0/237.0.86.1 to 7.0.87.2547.0.87.255510
457.0.88.0/237.0.88.1 to 7.0.89.2547.0.89.255510
467.0.90.0/237.0.90.1 to 7.0.91.2547.0.91.255510
477.0.92.0/237.0.92.1 to 7.0.93.2547.0.93.255510
487.0.94.0/237.0.94.1 to 7.0.95.2547.0.95.255510
497.0.96.0/237.0.96.1 to 7.0.97.2547.0.97.255510
507.0.98.0/237.0.98.1 to 7.0.99.2547.0.99.255510
517.0.100.0/237.0.100.1 to 7.0.101.2547.0.101.255510
527.0.102.0/237.0.102.1 to 7.0.103.2547.0.103.255510
537.0.104.0/237.0.104.1 to 7.0.105.2547.0.105.255510
547.0.106.0/237.0.106.1 to 7.0.107.2547.0.107.255510
557.0.108.0/237.0.108.1 to 7.0.109.2547.0.109.255510
567.0.110.0/237.0.110.1 to 7.0.111.2547.0.111.255510
577.0.112.0/237.0.112.1 to 7.0.113.2547.0.113.255510
587.0.114.0/237.0.114.1 to 7.0.115.2547.0.115.255510
597.0.116.0/237.0.116.1 to 7.0.117.2547.0.117.255510
607.0.118.0/237.0.118.1 to 7.0.119.2547.0.119.255510
617.0.120.0/237.0.120.1 to 7.0.121.2547.0.121.255510
627.0.122.0/237.0.122.1 to 7.0.123.2547.0.123.255510
637.0.124.0/237.0.124.1 to 7.0.125.2547.0.125.255510
647.0.126.0/237.0.126.1 to 7.0.127.2547.0.127.255510
657.0.128.0/237.0.128.1 to 7.0.129.2547.0.129.255510
667.0.130.0/237.0.130.1 to 7.0.131.2547.0.131.255510
677.0.132.0/237.0.132.1 to 7.0.133.2547.0.133.255510
687.0.134.0/237.0.134.1 to 7.0.135.2547.0.135.255510
697.0.136.0/237.0.136.1 to 7.0.137.2547.0.137.255510
707.0.138.0/237.0.138.1 to 7.0.139.2547.0.139.255510
717.0.140.0/237.0.140.1 to 7.0.141.2547.0.141.255510
727.0.142.0/237.0.142.1 to 7.0.143.2547.0.143.255510
737.0.144.0/237.0.144.1 to 7.0.145.2547.0.145.255510
747.0.146.0/237.0.146.1 to 7.0.147.2547.0.147.255510
757.0.148.0/237.0.148.1 to 7.0.149.2547.0.149.255510
767.0.150.0/237.0.150.1 to 7.0.151.2547.0.151.255510
777.0.152.0/237.0.152.1 to 7.0.153.2547.0.153.255510
787.0.154.0/237.0.154.1 to 7.0.155.2547.0.155.255510
797.0.156.0/237.0.156.1 to 7.0.157.2547.0.157.255510
807.0.158.0/237.0.158.1 to 7.0.159.2547.0.159.255510
817.0.160.0/237.0.160.1 to 7.0.161.2547.0.161.255510
827.0.162.0/237.0.162.1 to 7.0.163.2547.0.163.255510
837.0.164.0/237.0.164.1 to 7.0.165.2547.0.165.255510
847.0.166.0/237.0.166.1 to 7.0.167.2547.0.167.255510
857.0.168.0/237.0.168.1 to 7.0.169.2547.0.169.255510
867.0.170.0/237.0.170.1 to 7.0.171.2547.0.171.255510
877.0.172.0/237.0.172.1 to 7.0.173.2547.0.173.255510
887.0.174.0/237.0.174.1 to 7.0.175.2547.0.175.255510
897.0.176.0/237.0.176.1 to 7.0.177.2547.0.177.255510
907.0.178.0/237.0.178.1 to 7.0.179.2547.0.179.255510
917.0.180.0/237.0.180.1 to 7.0.181.2547.0.181.255510
927.0.182.0/237.0.182.1 to 7.0.183.2547.0.183.255510
937.0.184.0/237.0.184.1 to 7.0.185.2547.0.185.255510
947.0.186.0/237.0.186.1 to 7.0.187.2547.0.187.255510
957.0.188.0/237.0.188.1 to 7.0.189.2547.0.189.255510
967.0.190.0/237.0.190.1 to 7.0.191.2547.0.191.255510
977.0.192.0/237.0.192.1 to 7.0.193.2547.0.193.255510
987.0.194.0/237.0.194.1 to 7.0.195.2547.0.195.255510
997.0.196.0/237.0.196.1 to 7.0.197.2547.0.197.255510
1007.0.198.0/237.0.198.1 to 7.0.199.2547.0.199.255510
1017.0.200.0/237.0.200.1 to 7.0.201.2547.0.201.255510
1027.0.202.0/237.0.202.1 to 7.0.203.2547.0.203.255510
1037.0.204.0/237.0.204.1 to 7.0.205.2547.0.205.255510
1047.0.206.0/237.0.206.1 to 7.0.207.2547.0.207.255510
1057.0.208.0/237.0.208.1 to 7.0.209.2547.0.209.255510
1067.0.210.0/237.0.210.1 to 7.0.211.2547.0.211.255510
1077.0.212.0/237.0.212.1 to 7.0.213.2547.0.213.255510
1087.0.214.0/237.0.214.1 to 7.0.215.2547.0.215.255510
1097.0.216.0/237.0.216.1 to 7.0.217.2547.0.217.255510
1107.0.218.0/237.0.218.1 to 7.0.219.2547.0.219.255510
1117.0.220.0/237.0.220.1 to 7.0.221.2547.0.221.255510
1127.0.222.0/237.0.222.1 to 7.0.223.2547.0.223.255510
1137.0.224.0/237.0.224.1 to 7.0.225.2547.0.225.255510
1147.0.226.0/237.0.226.1 to 7.0.227.2547.0.227.255510
1157.0.228.0/237.0.228.1 to 7.0.229.2547.0.229.255510
1167.0.230.0/237.0.230.1 to 7.0.231.2547.0.231.255510
1177.0.232.0/237.0.232.1 to 7.0.233.2547.0.233.255510
1187.0.234.0/237.0.234.1 to 7.0.235.2547.0.235.255510
1197.0.236.0/237.0.236.1 to 7.0.237.2547.0.237.255510
1207.0.238.0/237.0.238.1 to 7.0.239.2547.0.239.255510
1217.0.240.0/237.0.240.1 to 7.0.241.2547.0.241.255510
1227.0.242.0/237.0.242.1 to 7.0.243.2547.0.243.255510
1237.0.244.0/237.0.244.1 to 7.0.245.2547.0.245.255510
1247.0.246.0/237.0.246.1 to 7.0.247.2547.0.247.255510
1257.0.248.0/237.0.248.1 to 7.0.249.2547.0.249.255510
1267.0.250.0/237.0.250.1 to 7.0.251.2547.0.251.255510
1277.0.252.0/237.0.252.1 to 7.0.253.2547.0.253.255510
1287.0.254.0/237.0.254.1 to 7.0.255.2547.0.255.255510
1297.1.0.0/237.1.0.1 to 7.1.1.2547.1.1.255510
1307.1.2.0/237.1.2.1 to 7.1.3.2547.1.3.255510
1317.1.4.0/237.1.4.1 to 7.1.5.2547.1.5.255510
1327.1.6.0/237.1.6.1 to 7.1.7.2547.1.7.255510
1337.1.8.0/237.1.8.1 to 7.1.9.2547.1.9.255510
1347.1.10.0/237.1.10.1 to 7.1.11.2547.1.11.255510
1357.1.12.0/237.1.12.1 to 7.1.13.2547.1.13.255510
1367.1.14.0/237.1.14.1 to 7.1.15.2547.1.15.255510
1377.1.16.0/237.1.16.1 to 7.1.17.2547.1.17.255510
1387.1.18.0/237.1.18.1 to 7.1.19.2547.1.19.255510
1397.1.20.0/237.1.20.1 to 7.1.21.2547.1.21.255510
1407.1.22.0/237.1.22.1 to 7.1.23.2547.1.23.255510
1417.1.24.0/237.1.24.1 to 7.1.25.2547.1.25.255510
1427.1.26.0/237.1.26.1 to 7.1.27.2547.1.27.255510
1437.1.28.0/237.1.28.1 to 7.1.29.2547.1.29.255510
1447.1.30.0/237.1.30.1 to 7.1.31.2547.1.31.255510
1457.1.32.0/237.1.32.1 to 7.1.33.2547.1.33.255510
1467.1.34.0/237.1.34.1 to 7.1.35.2547.1.35.255510
1477.1.36.0/237.1.36.1 to 7.1.37.2547.1.37.255510
1487.1.38.0/237.1.38.1 to 7.1.39.2547.1.39.255510
1497.1.40.0/237.1.40.1 to 7.1.41.2547.1.41.255510
1507.1.42.0/237.1.42.1 to 7.1.43.2547.1.43.255510
1517.1.44.0/237.1.44.1 to 7.1.45.2547.1.45.255510
1527.1.46.0/237.1.46.1 to 7.1.47.2547.1.47.255510
1537.1.48.0/237.1.48.1 to 7.1.49.2547.1.49.255510
1547.1.50.0/237.1.50.1 to 7.1.51.2547.1.51.255510
1557.1.52.0/237.1.52.1 to 7.1.53.2547.1.53.255510
1567.1.54.0/237.1.54.1 to 7.1.55.2547.1.55.255510
1577.1.56.0/237.1.56.1 to 7.1.57.2547.1.57.255510
1587.1.58.0/237.1.58.1 to 7.1.59.2547.1.59.255510
1597.1.60.0/237.1.60.1 to 7.1.61.2547.1.61.255510
1607.1.62.0/237.1.62.1 to 7.1.63.2547.1.63.255510
1617.1.64.0/237.1.64.1 to 7.1.65.2547.1.65.255510
1627.1.66.0/237.1.66.1 to 7.1.67.2547.1.67.255510
1637.1.68.0/237.1.68.1 to 7.1.69.2547.1.69.255510
1647.1.70.0/237.1.70.1 to 7.1.71.2547.1.71.255510
1657.1.72.0/237.1.72.1 to 7.1.73.2547.1.73.255510
1667.1.74.0/237.1.74.1 to 7.1.75.2547.1.75.255510
1677.1.76.0/237.1.76.1 to 7.1.77.2547.1.77.255510
1687.1.78.0/237.1.78.1 to 7.1.79.2547.1.79.255510
1697.1.80.0/237.1.80.1 to 7.1.81.2547.1.81.255510
1707.1.82.0/237.1.82.1 to 7.1.83.2547.1.83.255510
1717.1.84.0/237.1.84.1 to 7.1.85.2547.1.85.255510
1727.1.86.0/237.1.86.1 to 7.1.87.2547.1.87.255510
1737.1.88.0/237.1.88.1 to 7.1.89.2547.1.89.255510
1747.1.90.0/237.1.90.1 to 7.1.91.2547.1.91.255510
1757.1.92.0/237.1.92.1 to 7.1.93.2547.1.93.255510
1767.1.94.0/237.1.94.1 to 7.1.95.2547.1.95.255510
1777.1.96.0/237.1.96.1 to 7.1.97.2547.1.97.255510
1787.1.98.0/237.1.98.1 to 7.1.99.2547.1.99.255510
1797.1.100.0/237.1.100.1 to 7.1.101.2547.1.101.255510
1807.1.102.0/237.1.102.1 to 7.1.103.2547.1.103.255510
1817.1.104.0/237.1.104.1 to 7.1.105.2547.1.105.255510
1827.1.106.0/237.1.106.1 to 7.1.107.2547.1.107.255510
1837.1.108.0/237.1.108.1 to 7.1.109.2547.1.109.255510
1847.1.110.0/237.1.110.1 to 7.1.111.2547.1.111.255510
1857.1.112.0/237.1.112.1 to 7.1.113.2547.1.113.255510
1867.1.114.0/237.1.114.1 to 7.1.115.2547.1.115.255510
1877.1.116.0/237.1.116.1 to 7.1.117.2547.1.117.255510
1887.1.118.0/237.1.118.1 to 7.1.119.2547.1.119.255510
1897.1.120.0/237.1.120.1 to 7.1.121.2547.1.121.255510
1907.1.122.0/237.1.122.1 to 7.1.123.2547.1.123.255510
1917.1.124.0/237.1.124.1 to 7.1.125.2547.1.125.255510
1927.1.126.0/237.1.126.1 to 7.1.127.2547.1.127.255510
1937.1.128.0/237.1.128.1 to 7.1.129.2547.1.129.255510
1947.1.130.0/237.1.130.1 to 7.1.131.2547.1.131.255510
1957.1.132.0/237.1.132.1 to 7.1.133.2547.1.133.255510
1967.1.134.0/237.1.134.1 to 7.1.135.2547.1.135.255510
1977.1.136.0/237.1.136.1 to 7.1.137.2547.1.137.255510
1987.1.138.0/237.1.138.1 to 7.1.139.2547.1.139.255510
1997.1.140.0/237.1.140.1 to 7.1.141.2547.1.141.255510
2007.1.142.0/237.1.142.1 to 7.1.143.2547.1.143.255510
2017.1.144.0/237.1.144.1 to 7.1.145.2547.1.145.255510
2027.1.146.0/237.1.146.1 to 7.1.147.2547.1.147.255510
2037.1.148.0/237.1.148.1 to 7.1.149.2547.1.149.255510
2047.1.150.0/237.1.150.1 to 7.1.151.2547.1.151.255510
2057.1.152.0/237.1.152.1 to 7.1.153.2547.1.153.255510
2067.1.154.0/237.1.154.1 to 7.1.155.2547.1.155.255510
2077.1.156.0/237.1.156.1 to 7.1.157.2547.1.157.255510
2087.1.158.0/237.1.158.1 to 7.1.159.2547.1.159.255510
2097.1.160.0/237.1.160.1 to 7.1.161.2547.1.161.255510
2107.1.162.0/237.1.162.1 to 7.1.163.2547.1.163.255510
2117.1.164.0/237.1.164.1 to 7.1.165.2547.1.165.255510
2127.1.166.0/237.1.166.1 to 7.1.167.2547.1.167.255510
2137.1.168.0/237.1.168.1 to 7.1.169.2547.1.169.255510
2147.1.170.0/237.1.170.1 to 7.1.171.2547.1.171.255510
2157.1.172.0/237.1.172.1 to 7.1.173.2547.1.173.255510
2167.1.174.0/237.1.174.1 to 7.1.175.2547.1.175.255510
2177.1.176.0/237.1.176.1 to 7.1.177.2547.1.177.255510
2187.1.178.0/237.1.178.1 to 7.1.179.2547.1.179.255510
2197.1.180.0/237.1.180.1 to 7.1.181.2547.1.181.255510
2207.1.182.0/237.1.182.1 to 7.1.183.2547.1.183.255510
2217.1.184.0/237.1.184.1 to 7.1.185.2547.1.185.255510
2227.1.186.0/237.1.186.1 to 7.1.187.2547.1.187.255510
2237.1.188.0/237.1.188.1 to 7.1.189.2547.1.189.255510
2247.1.190.0/237.1.190.1 to 7.1.191.2547.1.191.255510
2257.1.192.0/237.1.192.1 to 7.1.193.2547.1.193.255510
2267.1.194.0/237.1.194.1 to 7.1.195.2547.1.195.255510
2277.1.196.0/237.1.196.1 to 7.1.197.2547.1.197.255510
2287.1.198.0/237.1.198.1 to 7.1.199.2547.1.199.255510
2297.1.200.0/237.1.200.1 to 7.1.201.2547.1.201.255510
2307.1.202.0/237.1.202.1 to 7.1.203.2547.1.203.255510
2317.1.204.0/237.1.204.1 to 7.1.205.2547.1.205.255510
2327.1.206.0/237.1.206.1 to 7.1.207.2547.1.207.255510
2337.1.208.0/237.1.208.1 to 7.1.209.2547.1.209.255510
2347.1.210.0/237.1.210.1 to 7.1.211.2547.1.211.255510
2357.1.212.0/237.1.212.1 to 7.1.213.2547.1.213.255510
2367.1.214.0/237.1.214.1 to 7.1.215.2547.1.215.255510
2377.1.216.0/237.1.216.1 to 7.1.217.2547.1.217.255510
2387.1.218.0/237.1.218.1 to 7.1.219.2547.1.219.255510
2397.1.220.0/237.1.220.1 to 7.1.221.2547.1.221.255510
2407.1.222.0/237.1.222.1 to 7.1.223.2547.1.223.255510
2417.1.224.0/237.1.224.1 to 7.1.225.2547.1.225.255510
2427.1.226.0/237.1.226.1 to 7.1.227.2547.1.227.255510
2437.1.228.0/237.1.228.1 to 7.1.229.2547.1.229.255510
2447.1.230.0/237.1.230.1 to 7.1.231.2547.1.231.255510
2457.1.232.0/237.1.232.1 to 7.1.233.2547.1.233.255510
2467.1.234.0/237.1.234.1 to 7.1.235.2547.1.235.255510
2477.1.236.0/237.1.236.1 to 7.1.237.2547.1.237.255510
2487.1.238.0/237.1.238.1 to 7.1.239.2547.1.239.255510
2497.1.240.0/237.1.240.1 to 7.1.241.2547.1.241.255510
2507.1.242.0/237.1.242.1 to 7.1.243.2547.1.243.255510
2517.1.244.0/237.1.244.1 to 7.1.245.2547.1.245.255510
2527.1.246.0/237.1.246.1 to 7.1.247.2547.1.247.255510
2537.1.248.0/237.1.248.1 to 7.1.249.2547.1.249.255510
2547.1.250.0/237.1.250.1 to 7.1.251.2547.1.251.255510
2557.1.252.0/237.1.252.1 to 7.1.253.2547.1.253.255510
2567.1.254.0/237.1.254.1 to 7.1.255.2547.1.255.255510

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.