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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.

Network7.48.0.0/12
Usable hosts1,048,574
Subnet mask255.240.0.0
Addresses1,048,576
Network address
7.48.0.0
Broadcast address
7.63.255.255
First usable
7.48.0.1
Last usable
7.63.255.254
Usable hosts
1,048,574 (1,048,576 less the network and broadcast addresses)
Subnet mask
255.240.0.0
Wildcard mask
0.15.255.255 (Cisco ACLs, OSPF)
Prefix length
/12
Type
Public public
Old class
A (default /8)
As numbers
Hex 07300000 · Integer 120586240 to 121634815
Reverse DNS zones
48.7.in-addr.arpa
49.7.in-addr.arpa
50.7.in-addr.arpa
51.7.in-addr.arpa
52.7.in-addr.arpa
53.7.in-addr.arpa
54.7.in-addr.arpa
55.7.in-addr.arpa
56.7.in-addr.arpa
57.7.in-addr.arpa
58.7.in-addr.arpa
59.7.in-addr.arpa
60.7.in-addr.arpa
61.7.in-addr.arpa
62.7.in-addr.arpa
63.7.in-addr.arpa
/12 is not on a 8-bit boundary, so it takes 16 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00000111.00110000.00000000.000000007.48.0.0
Subnet mask11111111.11110000.00000000.00000000255.240.0.0
Network00000111.00110000.00000000.000000007.48.0.0
Broadcast00000111.00111111.11111111.111111117.63.255.255
Split into smaller subnets/20
/13 (2)/14 (4)/15 (8)/16 (16)/17 (32)/18 (64)/19 (128)/20 (256)/21 (512)/22 (1,024)/23 (2,048)/24 (4,096)

7.48.0.0/12 makes 256 subnets of /20.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
17.48.0.0/207.48.0.1 to 7.48.15.2547.48.15.2554,094
27.48.16.0/207.48.16.1 to 7.48.31.2547.48.31.2554,094
37.48.32.0/207.48.32.1 to 7.48.47.2547.48.47.2554,094
47.48.48.0/207.48.48.1 to 7.48.63.2547.48.63.2554,094
57.48.64.0/207.48.64.1 to 7.48.79.2547.48.79.2554,094
67.48.80.0/207.48.80.1 to 7.48.95.2547.48.95.2554,094
77.48.96.0/207.48.96.1 to 7.48.111.2547.48.111.2554,094
87.48.112.0/207.48.112.1 to 7.48.127.2547.48.127.2554,094
97.48.128.0/207.48.128.1 to 7.48.143.2547.48.143.2554,094
107.48.144.0/207.48.144.1 to 7.48.159.2547.48.159.2554,094
117.48.160.0/207.48.160.1 to 7.48.175.2547.48.175.2554,094
127.48.176.0/207.48.176.1 to 7.48.191.2547.48.191.2554,094
137.48.192.0/207.48.192.1 to 7.48.207.2547.48.207.2554,094
147.48.208.0/207.48.208.1 to 7.48.223.2547.48.223.2554,094
157.48.224.0/207.48.224.1 to 7.48.239.2547.48.239.2554,094
167.48.240.0/207.48.240.1 to 7.48.255.2547.48.255.2554,094
177.49.0.0/207.49.0.1 to 7.49.15.2547.49.15.2554,094
187.49.16.0/207.49.16.1 to 7.49.31.2547.49.31.2554,094
197.49.32.0/207.49.32.1 to 7.49.47.2547.49.47.2554,094
207.49.48.0/207.49.48.1 to 7.49.63.2547.49.63.2554,094
217.49.64.0/207.49.64.1 to 7.49.79.2547.49.79.2554,094
227.49.80.0/207.49.80.1 to 7.49.95.2547.49.95.2554,094
237.49.96.0/207.49.96.1 to 7.49.111.2547.49.111.2554,094
247.49.112.0/207.49.112.1 to 7.49.127.2547.49.127.2554,094
257.49.128.0/207.49.128.1 to 7.49.143.2547.49.143.2554,094
267.49.144.0/207.49.144.1 to 7.49.159.2547.49.159.2554,094
277.49.160.0/207.49.160.1 to 7.49.175.2547.49.175.2554,094
287.49.176.0/207.49.176.1 to 7.49.191.2547.49.191.2554,094
297.49.192.0/207.49.192.1 to 7.49.207.2547.49.207.2554,094
307.49.208.0/207.49.208.1 to 7.49.223.2547.49.223.2554,094
317.49.224.0/207.49.224.1 to 7.49.239.2547.49.239.2554,094
327.49.240.0/207.49.240.1 to 7.49.255.2547.49.255.2554,094
337.50.0.0/207.50.0.1 to 7.50.15.2547.50.15.2554,094
347.50.16.0/207.50.16.1 to 7.50.31.2547.50.31.2554,094
357.50.32.0/207.50.32.1 to 7.50.47.2547.50.47.2554,094
367.50.48.0/207.50.48.1 to 7.50.63.2547.50.63.2554,094
377.50.64.0/207.50.64.1 to 7.50.79.2547.50.79.2554,094
387.50.80.0/207.50.80.1 to 7.50.95.2547.50.95.2554,094
397.50.96.0/207.50.96.1 to 7.50.111.2547.50.111.2554,094
407.50.112.0/207.50.112.1 to 7.50.127.2547.50.127.2554,094
417.50.128.0/207.50.128.1 to 7.50.143.2547.50.143.2554,094
427.50.144.0/207.50.144.1 to 7.50.159.2547.50.159.2554,094
437.50.160.0/207.50.160.1 to 7.50.175.2547.50.175.2554,094
447.50.176.0/207.50.176.1 to 7.50.191.2547.50.191.2554,094
457.50.192.0/207.50.192.1 to 7.50.207.2547.50.207.2554,094
467.50.208.0/207.50.208.1 to 7.50.223.2547.50.223.2554,094
477.50.224.0/207.50.224.1 to 7.50.239.2547.50.239.2554,094
487.50.240.0/207.50.240.1 to 7.50.255.2547.50.255.2554,094
497.51.0.0/207.51.0.1 to 7.51.15.2547.51.15.2554,094
507.51.16.0/207.51.16.1 to 7.51.31.2547.51.31.2554,094
517.51.32.0/207.51.32.1 to 7.51.47.2547.51.47.2554,094
527.51.48.0/207.51.48.1 to 7.51.63.2547.51.63.2554,094
537.51.64.0/207.51.64.1 to 7.51.79.2547.51.79.2554,094
547.51.80.0/207.51.80.1 to 7.51.95.2547.51.95.2554,094
557.51.96.0/207.51.96.1 to 7.51.111.2547.51.111.2554,094
567.51.112.0/207.51.112.1 to 7.51.127.2547.51.127.2554,094
577.51.128.0/207.51.128.1 to 7.51.143.2547.51.143.2554,094
587.51.144.0/207.51.144.1 to 7.51.159.2547.51.159.2554,094
597.51.160.0/207.51.160.1 to 7.51.175.2547.51.175.2554,094
607.51.176.0/207.51.176.1 to 7.51.191.2547.51.191.2554,094
617.51.192.0/207.51.192.1 to 7.51.207.2547.51.207.2554,094
627.51.208.0/207.51.208.1 to 7.51.223.2547.51.223.2554,094
637.51.224.0/207.51.224.1 to 7.51.239.2547.51.239.2554,094
647.51.240.0/207.51.240.1 to 7.51.255.2547.51.255.2554,094
657.52.0.0/207.52.0.1 to 7.52.15.2547.52.15.2554,094
667.52.16.0/207.52.16.1 to 7.52.31.2547.52.31.2554,094
677.52.32.0/207.52.32.1 to 7.52.47.2547.52.47.2554,094
687.52.48.0/207.52.48.1 to 7.52.63.2547.52.63.2554,094
697.52.64.0/207.52.64.1 to 7.52.79.2547.52.79.2554,094
707.52.80.0/207.52.80.1 to 7.52.95.2547.52.95.2554,094
717.52.96.0/207.52.96.1 to 7.52.111.2547.52.111.2554,094
727.52.112.0/207.52.112.1 to 7.52.127.2547.52.127.2554,094
737.52.128.0/207.52.128.1 to 7.52.143.2547.52.143.2554,094
747.52.144.0/207.52.144.1 to 7.52.159.2547.52.159.2554,094
757.52.160.0/207.52.160.1 to 7.52.175.2547.52.175.2554,094
767.52.176.0/207.52.176.1 to 7.52.191.2547.52.191.2554,094
777.52.192.0/207.52.192.1 to 7.52.207.2547.52.207.2554,094
787.52.208.0/207.52.208.1 to 7.52.223.2547.52.223.2554,094
797.52.224.0/207.52.224.1 to 7.52.239.2547.52.239.2554,094
807.52.240.0/207.52.240.1 to 7.52.255.2547.52.255.2554,094
817.53.0.0/207.53.0.1 to 7.53.15.2547.53.15.2554,094
827.53.16.0/207.53.16.1 to 7.53.31.2547.53.31.2554,094
837.53.32.0/207.53.32.1 to 7.53.47.2547.53.47.2554,094
847.53.48.0/207.53.48.1 to 7.53.63.2547.53.63.2554,094
857.53.64.0/207.53.64.1 to 7.53.79.2547.53.79.2554,094
867.53.80.0/207.53.80.1 to 7.53.95.2547.53.95.2554,094
877.53.96.0/207.53.96.1 to 7.53.111.2547.53.111.2554,094
887.53.112.0/207.53.112.1 to 7.53.127.2547.53.127.2554,094
897.53.128.0/207.53.128.1 to 7.53.143.2547.53.143.2554,094
907.53.144.0/207.53.144.1 to 7.53.159.2547.53.159.2554,094
917.53.160.0/207.53.160.1 to 7.53.175.2547.53.175.2554,094
927.53.176.0/207.53.176.1 to 7.53.191.2547.53.191.2554,094
937.53.192.0/207.53.192.1 to 7.53.207.2547.53.207.2554,094
947.53.208.0/207.53.208.1 to 7.53.223.2547.53.223.2554,094
957.53.224.0/207.53.224.1 to 7.53.239.2547.53.239.2554,094
967.53.240.0/207.53.240.1 to 7.53.255.2547.53.255.2554,094
977.54.0.0/207.54.0.1 to 7.54.15.2547.54.15.2554,094
987.54.16.0/207.54.16.1 to 7.54.31.2547.54.31.2554,094
997.54.32.0/207.54.32.1 to 7.54.47.2547.54.47.2554,094
1007.54.48.0/207.54.48.1 to 7.54.63.2547.54.63.2554,094
1017.54.64.0/207.54.64.1 to 7.54.79.2547.54.79.2554,094
1027.54.80.0/207.54.80.1 to 7.54.95.2547.54.95.2554,094
1037.54.96.0/207.54.96.1 to 7.54.111.2547.54.111.2554,094
1047.54.112.0/207.54.112.1 to 7.54.127.2547.54.127.2554,094
1057.54.128.0/207.54.128.1 to 7.54.143.2547.54.143.2554,094
1067.54.144.0/207.54.144.1 to 7.54.159.2547.54.159.2554,094
1077.54.160.0/207.54.160.1 to 7.54.175.2547.54.175.2554,094
1087.54.176.0/207.54.176.1 to 7.54.191.2547.54.191.2554,094
1097.54.192.0/207.54.192.1 to 7.54.207.2547.54.207.2554,094
1107.54.208.0/207.54.208.1 to 7.54.223.2547.54.223.2554,094
1117.54.224.0/207.54.224.1 to 7.54.239.2547.54.239.2554,094
1127.54.240.0/207.54.240.1 to 7.54.255.2547.54.255.2554,094
1137.55.0.0/207.55.0.1 to 7.55.15.2547.55.15.2554,094
1147.55.16.0/207.55.16.1 to 7.55.31.2547.55.31.2554,094
1157.55.32.0/207.55.32.1 to 7.55.47.2547.55.47.2554,094
1167.55.48.0/207.55.48.1 to 7.55.63.2547.55.63.2554,094
1177.55.64.0/207.55.64.1 to 7.55.79.2547.55.79.2554,094
1187.55.80.0/207.55.80.1 to 7.55.95.2547.55.95.2554,094
1197.55.96.0/207.55.96.1 to 7.55.111.2547.55.111.2554,094
1207.55.112.0/207.55.112.1 to 7.55.127.2547.55.127.2554,094
1217.55.128.0/207.55.128.1 to 7.55.143.2547.55.143.2554,094
1227.55.144.0/207.55.144.1 to 7.55.159.2547.55.159.2554,094
1237.55.160.0/207.55.160.1 to 7.55.175.2547.55.175.2554,094
1247.55.176.0/207.55.176.1 to 7.55.191.2547.55.191.2554,094
1257.55.192.0/207.55.192.1 to 7.55.207.2547.55.207.2554,094
1267.55.208.0/207.55.208.1 to 7.55.223.2547.55.223.2554,094
1277.55.224.0/207.55.224.1 to 7.55.239.2547.55.239.2554,094
1287.55.240.0/207.55.240.1 to 7.55.255.2547.55.255.2554,094
1297.56.0.0/207.56.0.1 to 7.56.15.2547.56.15.2554,094
1307.56.16.0/207.56.16.1 to 7.56.31.2547.56.31.2554,094
1317.56.32.0/207.56.32.1 to 7.56.47.2547.56.47.2554,094
1327.56.48.0/207.56.48.1 to 7.56.63.2547.56.63.2554,094
1337.56.64.0/207.56.64.1 to 7.56.79.2547.56.79.2554,094
1347.56.80.0/207.56.80.1 to 7.56.95.2547.56.95.2554,094
1357.56.96.0/207.56.96.1 to 7.56.111.2547.56.111.2554,094
1367.56.112.0/207.56.112.1 to 7.56.127.2547.56.127.2554,094
1377.56.128.0/207.56.128.1 to 7.56.143.2547.56.143.2554,094
1387.56.144.0/207.56.144.1 to 7.56.159.2547.56.159.2554,094
1397.56.160.0/207.56.160.1 to 7.56.175.2547.56.175.2554,094
1407.56.176.0/207.56.176.1 to 7.56.191.2547.56.191.2554,094
1417.56.192.0/207.56.192.1 to 7.56.207.2547.56.207.2554,094
1427.56.208.0/207.56.208.1 to 7.56.223.2547.56.223.2554,094
1437.56.224.0/207.56.224.1 to 7.56.239.2547.56.239.2554,094
1447.56.240.0/207.56.240.1 to 7.56.255.2547.56.255.2554,094
1457.57.0.0/207.57.0.1 to 7.57.15.2547.57.15.2554,094
1467.57.16.0/207.57.16.1 to 7.57.31.2547.57.31.2554,094
1477.57.32.0/207.57.32.1 to 7.57.47.2547.57.47.2554,094
1487.57.48.0/207.57.48.1 to 7.57.63.2547.57.63.2554,094
1497.57.64.0/207.57.64.1 to 7.57.79.2547.57.79.2554,094
1507.57.80.0/207.57.80.1 to 7.57.95.2547.57.95.2554,094
1517.57.96.0/207.57.96.1 to 7.57.111.2547.57.111.2554,094
1527.57.112.0/207.57.112.1 to 7.57.127.2547.57.127.2554,094
1537.57.128.0/207.57.128.1 to 7.57.143.2547.57.143.2554,094
1547.57.144.0/207.57.144.1 to 7.57.159.2547.57.159.2554,094
1557.57.160.0/207.57.160.1 to 7.57.175.2547.57.175.2554,094
1567.57.176.0/207.57.176.1 to 7.57.191.2547.57.191.2554,094
1577.57.192.0/207.57.192.1 to 7.57.207.2547.57.207.2554,094
1587.57.208.0/207.57.208.1 to 7.57.223.2547.57.223.2554,094
1597.57.224.0/207.57.224.1 to 7.57.239.2547.57.239.2554,094
1607.57.240.0/207.57.240.1 to 7.57.255.2547.57.255.2554,094
1617.58.0.0/207.58.0.1 to 7.58.15.2547.58.15.2554,094
1627.58.16.0/207.58.16.1 to 7.58.31.2547.58.31.2554,094
1637.58.32.0/207.58.32.1 to 7.58.47.2547.58.47.2554,094
1647.58.48.0/207.58.48.1 to 7.58.63.2547.58.63.2554,094
1657.58.64.0/207.58.64.1 to 7.58.79.2547.58.79.2554,094
1667.58.80.0/207.58.80.1 to 7.58.95.2547.58.95.2554,094
1677.58.96.0/207.58.96.1 to 7.58.111.2547.58.111.2554,094
1687.58.112.0/207.58.112.1 to 7.58.127.2547.58.127.2554,094
1697.58.128.0/207.58.128.1 to 7.58.143.2547.58.143.2554,094
1707.58.144.0/207.58.144.1 to 7.58.159.2547.58.159.2554,094
1717.58.160.0/207.58.160.1 to 7.58.175.2547.58.175.2554,094
1727.58.176.0/207.58.176.1 to 7.58.191.2547.58.191.2554,094
1737.58.192.0/207.58.192.1 to 7.58.207.2547.58.207.2554,094
1747.58.208.0/207.58.208.1 to 7.58.223.2547.58.223.2554,094
1757.58.224.0/207.58.224.1 to 7.58.239.2547.58.239.2554,094
1767.58.240.0/207.58.240.1 to 7.58.255.2547.58.255.2554,094
1777.59.0.0/207.59.0.1 to 7.59.15.2547.59.15.2554,094
1787.59.16.0/207.59.16.1 to 7.59.31.2547.59.31.2554,094
1797.59.32.0/207.59.32.1 to 7.59.47.2547.59.47.2554,094
1807.59.48.0/207.59.48.1 to 7.59.63.2547.59.63.2554,094
1817.59.64.0/207.59.64.1 to 7.59.79.2547.59.79.2554,094
1827.59.80.0/207.59.80.1 to 7.59.95.2547.59.95.2554,094
1837.59.96.0/207.59.96.1 to 7.59.111.2547.59.111.2554,094
1847.59.112.0/207.59.112.1 to 7.59.127.2547.59.127.2554,094
1857.59.128.0/207.59.128.1 to 7.59.143.2547.59.143.2554,094
1867.59.144.0/207.59.144.1 to 7.59.159.2547.59.159.2554,094
1877.59.160.0/207.59.160.1 to 7.59.175.2547.59.175.2554,094
1887.59.176.0/207.59.176.1 to 7.59.191.2547.59.191.2554,094
1897.59.192.0/207.59.192.1 to 7.59.207.2547.59.207.2554,094
1907.59.208.0/207.59.208.1 to 7.59.223.2547.59.223.2554,094
1917.59.224.0/207.59.224.1 to 7.59.239.2547.59.239.2554,094
1927.59.240.0/207.59.240.1 to 7.59.255.2547.59.255.2554,094
1937.60.0.0/207.60.0.1 to 7.60.15.2547.60.15.2554,094
1947.60.16.0/207.60.16.1 to 7.60.31.2547.60.31.2554,094
1957.60.32.0/207.60.32.1 to 7.60.47.2547.60.47.2554,094
1967.60.48.0/207.60.48.1 to 7.60.63.2547.60.63.2554,094
1977.60.64.0/207.60.64.1 to 7.60.79.2547.60.79.2554,094
1987.60.80.0/207.60.80.1 to 7.60.95.2547.60.95.2554,094
1997.60.96.0/207.60.96.1 to 7.60.111.2547.60.111.2554,094
2007.60.112.0/207.60.112.1 to 7.60.127.2547.60.127.2554,094
2017.60.128.0/207.60.128.1 to 7.60.143.2547.60.143.2554,094
2027.60.144.0/207.60.144.1 to 7.60.159.2547.60.159.2554,094
2037.60.160.0/207.60.160.1 to 7.60.175.2547.60.175.2554,094
2047.60.176.0/207.60.176.1 to 7.60.191.2547.60.191.2554,094
2057.60.192.0/207.60.192.1 to 7.60.207.2547.60.207.2554,094
2067.60.208.0/207.60.208.1 to 7.60.223.2547.60.223.2554,094
2077.60.224.0/207.60.224.1 to 7.60.239.2547.60.239.2554,094
2087.60.240.0/207.60.240.1 to 7.60.255.2547.60.255.2554,094
2097.61.0.0/207.61.0.1 to 7.61.15.2547.61.15.2554,094
2107.61.16.0/207.61.16.1 to 7.61.31.2547.61.31.2554,094
2117.61.32.0/207.61.32.1 to 7.61.47.2547.61.47.2554,094
2127.61.48.0/207.61.48.1 to 7.61.63.2547.61.63.2554,094
2137.61.64.0/207.61.64.1 to 7.61.79.2547.61.79.2554,094
2147.61.80.0/207.61.80.1 to 7.61.95.2547.61.95.2554,094
2157.61.96.0/207.61.96.1 to 7.61.111.2547.61.111.2554,094
2167.61.112.0/207.61.112.1 to 7.61.127.2547.61.127.2554,094
2177.61.128.0/207.61.128.1 to 7.61.143.2547.61.143.2554,094
2187.61.144.0/207.61.144.1 to 7.61.159.2547.61.159.2554,094
2197.61.160.0/207.61.160.1 to 7.61.175.2547.61.175.2554,094
2207.61.176.0/207.61.176.1 to 7.61.191.2547.61.191.2554,094
2217.61.192.0/207.61.192.1 to 7.61.207.2547.61.207.2554,094
2227.61.208.0/207.61.208.1 to 7.61.223.2547.61.223.2554,094
2237.61.224.0/207.61.224.1 to 7.61.239.2547.61.239.2554,094
2247.61.240.0/207.61.240.1 to 7.61.255.2547.61.255.2554,094
2257.62.0.0/207.62.0.1 to 7.62.15.2547.62.15.2554,094
2267.62.16.0/207.62.16.1 to 7.62.31.2547.62.31.2554,094
2277.62.32.0/207.62.32.1 to 7.62.47.2547.62.47.2554,094
2287.62.48.0/207.62.48.1 to 7.62.63.2547.62.63.2554,094
2297.62.64.0/207.62.64.1 to 7.62.79.2547.62.79.2554,094
2307.62.80.0/207.62.80.1 to 7.62.95.2547.62.95.2554,094
2317.62.96.0/207.62.96.1 to 7.62.111.2547.62.111.2554,094
2327.62.112.0/207.62.112.1 to 7.62.127.2547.62.127.2554,094
2337.62.128.0/207.62.128.1 to 7.62.143.2547.62.143.2554,094
2347.62.144.0/207.62.144.1 to 7.62.159.2547.62.159.2554,094
2357.62.160.0/207.62.160.1 to 7.62.175.2547.62.175.2554,094
2367.62.176.0/207.62.176.1 to 7.62.191.2547.62.191.2554,094
2377.62.192.0/207.62.192.1 to 7.62.207.2547.62.207.2554,094
2387.62.208.0/207.62.208.1 to 7.62.223.2547.62.223.2554,094
2397.62.224.0/207.62.224.1 to 7.62.239.2547.62.239.2554,094
2407.62.240.0/207.62.240.1 to 7.62.255.2547.62.255.2554,094
2417.63.0.0/207.63.0.1 to 7.63.15.2547.63.15.2554,094
2427.63.16.0/207.63.16.1 to 7.63.31.2547.63.31.2554,094
2437.63.32.0/207.63.32.1 to 7.63.47.2547.63.47.2554,094
2447.63.48.0/207.63.48.1 to 7.63.63.2547.63.63.2554,094
2457.63.64.0/207.63.64.1 to 7.63.79.2547.63.79.2554,094
2467.63.80.0/207.63.80.1 to 7.63.95.2547.63.95.2554,094
2477.63.96.0/207.63.96.1 to 7.63.111.2547.63.111.2554,094
2487.63.112.0/207.63.112.1 to 7.63.127.2547.63.127.2554,094
2497.63.128.0/207.63.128.1 to 7.63.143.2547.63.143.2554,094
2507.63.144.0/207.63.144.1 to 7.63.159.2547.63.159.2554,094
2517.63.160.0/207.63.160.1 to 7.63.175.2547.63.175.2554,094
2527.63.176.0/207.63.176.1 to 7.63.191.2547.63.191.2554,094
2537.63.192.0/207.63.192.1 to 7.63.207.2547.63.207.2554,094
2547.63.208.0/207.63.208.1 to 7.63.223.2547.63.223.2554,094
2557.63.224.0/207.63.224.1 to 7.63.239.2547.63.239.2554,094
2567.63.240.0/207.63.240.1 to 7.63.255.2547.63.255.2554,094

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.