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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.

Prefix/16
Addresses2^112
/64 networks2^48
Network
2038::/16
First address
2038::
Last address
2038:ffff:ffff:ffff:ffff:ffff:ffff:ffff
Addresses
5,192,296,858,534,827,628,530,496,329,220,096 (2^112)
/64 networks (LANs)
281,474,976,710,656 (2^48)
Full form
2038:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
8.3.0.2.ip6.arpa
Split into smaller subnets/24
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

2038::/16 makes 256 subnets of /24.

Subnets
#SubnetLast address
12038::/242038:ff:ffff:ffff:ffff:ffff:ffff:ffff
22038:100::/242038:1ff:ffff:ffff:ffff:ffff:ffff:ffff
32038:200::/242038:2ff:ffff:ffff:ffff:ffff:ffff:ffff
42038:300::/242038:3ff:ffff:ffff:ffff:ffff:ffff:ffff
52038:400::/242038:4ff:ffff:ffff:ffff:ffff:ffff:ffff
62038:500::/242038:5ff:ffff:ffff:ffff:ffff:ffff:ffff
72038:600::/242038:6ff:ffff:ffff:ffff:ffff:ffff:ffff
82038:700::/242038:7ff:ffff:ffff:ffff:ffff:ffff:ffff
92038:800::/242038:8ff:ffff:ffff:ffff:ffff:ffff:ffff
102038:900::/242038:9ff:ffff:ffff:ffff:ffff:ffff:ffff
112038:a00::/242038:aff:ffff:ffff:ffff:ffff:ffff:ffff
122038:b00::/242038:bff:ffff:ffff:ffff:ffff:ffff:ffff
132038:c00::/242038:cff:ffff:ffff:ffff:ffff:ffff:ffff
142038:d00::/242038:dff:ffff:ffff:ffff:ffff:ffff:ffff
152038:e00::/242038:eff:ffff:ffff:ffff:ffff:ffff:ffff
162038:f00::/242038:fff:ffff:ffff:ffff:ffff:ffff:ffff
172038:1000::/242038:10ff:ffff:ffff:ffff:ffff:ffff:ffff
182038:1100::/242038:11ff:ffff:ffff:ffff:ffff:ffff:ffff
192038:1200::/242038:12ff:ffff:ffff:ffff:ffff:ffff:ffff
202038:1300::/242038:13ff:ffff:ffff:ffff:ffff:ffff:ffff
212038:1400::/242038:14ff:ffff:ffff:ffff:ffff:ffff:ffff
222038:1500::/242038:15ff:ffff:ffff:ffff:ffff:ffff:ffff
232038:1600::/242038:16ff:ffff:ffff:ffff:ffff:ffff:ffff
242038:1700::/242038:17ff:ffff:ffff:ffff:ffff:ffff:ffff
252038:1800::/242038:18ff:ffff:ffff:ffff:ffff:ffff:ffff
262038:1900::/242038:19ff:ffff:ffff:ffff:ffff:ffff:ffff
272038:1a00::/242038:1aff:ffff:ffff:ffff:ffff:ffff:ffff
282038:1b00::/242038:1bff:ffff:ffff:ffff:ffff:ffff:ffff
292038:1c00::/242038:1cff:ffff:ffff:ffff:ffff:ffff:ffff
302038:1d00::/242038:1dff:ffff:ffff:ffff:ffff:ffff:ffff
312038:1e00::/242038:1eff:ffff:ffff:ffff:ffff:ffff:ffff
322038:1f00::/242038:1fff:ffff:ffff:ffff:ffff:ffff:ffff
332038:2000::/242038:20ff:ffff:ffff:ffff:ffff:ffff:ffff
342038:2100::/242038:21ff:ffff:ffff:ffff:ffff:ffff:ffff
352038:2200::/242038:22ff:ffff:ffff:ffff:ffff:ffff:ffff
362038:2300::/242038:23ff:ffff:ffff:ffff:ffff:ffff:ffff
372038:2400::/242038:24ff:ffff:ffff:ffff:ffff:ffff:ffff
382038:2500::/242038:25ff:ffff:ffff:ffff:ffff:ffff:ffff
392038:2600::/242038:26ff:ffff:ffff:ffff:ffff:ffff:ffff
402038:2700::/242038:27ff:ffff:ffff:ffff:ffff:ffff:ffff
412038:2800::/242038:28ff:ffff:ffff:ffff:ffff:ffff:ffff
422038:2900::/242038:29ff:ffff:ffff:ffff:ffff:ffff:ffff
432038:2a00::/242038:2aff:ffff:ffff:ffff:ffff:ffff:ffff
442038:2b00::/242038:2bff:ffff:ffff:ffff:ffff:ffff:ffff
452038:2c00::/242038:2cff:ffff:ffff:ffff:ffff:ffff:ffff
462038:2d00::/242038:2dff:ffff:ffff:ffff:ffff:ffff:ffff
472038:2e00::/242038:2eff:ffff:ffff:ffff:ffff:ffff:ffff
482038:2f00::/242038:2fff:ffff:ffff:ffff:ffff:ffff:ffff
492038:3000::/242038:30ff:ffff:ffff:ffff:ffff:ffff:ffff
502038:3100::/242038:31ff:ffff:ffff:ffff:ffff:ffff:ffff
512038:3200::/242038:32ff:ffff:ffff:ffff:ffff:ffff:ffff
522038:3300::/242038:33ff:ffff:ffff:ffff:ffff:ffff:ffff
532038:3400::/242038:34ff:ffff:ffff:ffff:ffff:ffff:ffff
542038:3500::/242038:35ff:ffff:ffff:ffff:ffff:ffff:ffff
552038:3600::/242038:36ff:ffff:ffff:ffff:ffff:ffff:ffff
562038:3700::/242038:37ff:ffff:ffff:ffff:ffff:ffff:ffff
572038:3800::/242038:38ff:ffff:ffff:ffff:ffff:ffff:ffff
582038:3900::/242038:39ff:ffff:ffff:ffff:ffff:ffff:ffff
592038:3a00::/242038:3aff:ffff:ffff:ffff:ffff:ffff:ffff
602038:3b00::/242038:3bff:ffff:ffff:ffff:ffff:ffff:ffff
612038:3c00::/242038:3cff:ffff:ffff:ffff:ffff:ffff:ffff
622038:3d00::/242038:3dff:ffff:ffff:ffff:ffff:ffff:ffff
632038:3e00::/242038:3eff:ffff:ffff:ffff:ffff:ffff:ffff
642038:3f00::/242038:3fff:ffff:ffff:ffff:ffff:ffff:ffff
652038:4000::/242038:40ff:ffff:ffff:ffff:ffff:ffff:ffff
662038:4100::/242038:41ff:ffff:ffff:ffff:ffff:ffff:ffff
672038:4200::/242038:42ff:ffff:ffff:ffff:ffff:ffff:ffff
682038:4300::/242038:43ff:ffff:ffff:ffff:ffff:ffff:ffff
692038:4400::/242038:44ff:ffff:ffff:ffff:ffff:ffff:ffff
702038:4500::/242038:45ff:ffff:ffff:ffff:ffff:ffff:ffff
712038:4600::/242038:46ff:ffff:ffff:ffff:ffff:ffff:ffff
722038:4700::/242038:47ff:ffff:ffff:ffff:ffff:ffff:ffff
732038:4800::/242038:48ff:ffff:ffff:ffff:ffff:ffff:ffff
742038:4900::/242038:49ff:ffff:ffff:ffff:ffff:ffff:ffff
752038:4a00::/242038:4aff:ffff:ffff:ffff:ffff:ffff:ffff
762038:4b00::/242038:4bff:ffff:ffff:ffff:ffff:ffff:ffff
772038:4c00::/242038:4cff:ffff:ffff:ffff:ffff:ffff:ffff
782038:4d00::/242038:4dff:ffff:ffff:ffff:ffff:ffff:ffff
792038:4e00::/242038:4eff:ffff:ffff:ffff:ffff:ffff:ffff
802038:4f00::/242038:4fff:ffff:ffff:ffff:ffff:ffff:ffff
812038:5000::/242038:50ff:ffff:ffff:ffff:ffff:ffff:ffff
822038:5100::/242038:51ff:ffff:ffff:ffff:ffff:ffff:ffff
832038:5200::/242038:52ff:ffff:ffff:ffff:ffff:ffff:ffff
842038:5300::/242038:53ff:ffff:ffff:ffff:ffff:ffff:ffff
852038:5400::/242038:54ff:ffff:ffff:ffff:ffff:ffff:ffff
862038:5500::/242038:55ff:ffff:ffff:ffff:ffff:ffff:ffff
872038:5600::/242038:56ff:ffff:ffff:ffff:ffff:ffff:ffff
882038:5700::/242038:57ff:ffff:ffff:ffff:ffff:ffff:ffff
892038:5800::/242038:58ff:ffff:ffff:ffff:ffff:ffff:ffff
902038:5900::/242038:59ff:ffff:ffff:ffff:ffff:ffff:ffff
912038:5a00::/242038:5aff:ffff:ffff:ffff:ffff:ffff:ffff
922038:5b00::/242038:5bff:ffff:ffff:ffff:ffff:ffff:ffff
932038:5c00::/242038:5cff:ffff:ffff:ffff:ffff:ffff:ffff
942038:5d00::/242038:5dff:ffff:ffff:ffff:ffff:ffff:ffff
952038:5e00::/242038:5eff:ffff:ffff:ffff:ffff:ffff:ffff
962038:5f00::/242038:5fff:ffff:ffff:ffff:ffff:ffff:ffff
972038:6000::/242038:60ff:ffff:ffff:ffff:ffff:ffff:ffff
982038:6100::/242038:61ff:ffff:ffff:ffff:ffff:ffff:ffff
992038:6200::/242038:62ff:ffff:ffff:ffff:ffff:ffff:ffff
1002038:6300::/242038:63ff:ffff:ffff:ffff:ffff:ffff:ffff
1012038:6400::/242038:64ff:ffff:ffff:ffff:ffff:ffff:ffff
1022038:6500::/242038:65ff:ffff:ffff:ffff:ffff:ffff:ffff
1032038:6600::/242038:66ff:ffff:ffff:ffff:ffff:ffff:ffff
1042038:6700::/242038:67ff:ffff:ffff:ffff:ffff:ffff:ffff
1052038:6800::/242038:68ff:ffff:ffff:ffff:ffff:ffff:ffff
1062038:6900::/242038:69ff:ffff:ffff:ffff:ffff:ffff:ffff
1072038:6a00::/242038:6aff:ffff:ffff:ffff:ffff:ffff:ffff
1082038:6b00::/242038:6bff:ffff:ffff:ffff:ffff:ffff:ffff
1092038:6c00::/242038:6cff:ffff:ffff:ffff:ffff:ffff:ffff
1102038:6d00::/242038:6dff:ffff:ffff:ffff:ffff:ffff:ffff
1112038:6e00::/242038:6eff:ffff:ffff:ffff:ffff:ffff:ffff
1122038:6f00::/242038:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1132038:7000::/242038:70ff:ffff:ffff:ffff:ffff:ffff:ffff
1142038:7100::/242038:71ff:ffff:ffff:ffff:ffff:ffff:ffff
1152038:7200::/242038:72ff:ffff:ffff:ffff:ffff:ffff:ffff
1162038:7300::/242038:73ff:ffff:ffff:ffff:ffff:ffff:ffff
1172038:7400::/242038:74ff:ffff:ffff:ffff:ffff:ffff:ffff
1182038:7500::/242038:75ff:ffff:ffff:ffff:ffff:ffff:ffff
1192038:7600::/242038:76ff:ffff:ffff:ffff:ffff:ffff:ffff
1202038:7700::/242038:77ff:ffff:ffff:ffff:ffff:ffff:ffff
1212038:7800::/242038:78ff:ffff:ffff:ffff:ffff:ffff:ffff
1222038:7900::/242038:79ff:ffff:ffff:ffff:ffff:ffff:ffff
1232038:7a00::/242038:7aff:ffff:ffff:ffff:ffff:ffff:ffff
1242038:7b00::/242038:7bff:ffff:ffff:ffff:ffff:ffff:ffff
1252038:7c00::/242038:7cff:ffff:ffff:ffff:ffff:ffff:ffff
1262038:7d00::/242038:7dff:ffff:ffff:ffff:ffff:ffff:ffff
1272038:7e00::/242038:7eff:ffff:ffff:ffff:ffff:ffff:ffff
1282038:7f00::/242038:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1292038:8000::/242038:80ff:ffff:ffff:ffff:ffff:ffff:ffff
1302038:8100::/242038:81ff:ffff:ffff:ffff:ffff:ffff:ffff
1312038:8200::/242038:82ff:ffff:ffff:ffff:ffff:ffff:ffff
1322038:8300::/242038:83ff:ffff:ffff:ffff:ffff:ffff:ffff
1332038:8400::/242038:84ff:ffff:ffff:ffff:ffff:ffff:ffff
1342038:8500::/242038:85ff:ffff:ffff:ffff:ffff:ffff:ffff
1352038:8600::/242038:86ff:ffff:ffff:ffff:ffff:ffff:ffff
1362038:8700::/242038:87ff:ffff:ffff:ffff:ffff:ffff:ffff
1372038:8800::/242038:88ff:ffff:ffff:ffff:ffff:ffff:ffff
1382038:8900::/242038:89ff:ffff:ffff:ffff:ffff:ffff:ffff
1392038:8a00::/242038:8aff:ffff:ffff:ffff:ffff:ffff:ffff
1402038:8b00::/242038:8bff:ffff:ffff:ffff:ffff:ffff:ffff
1412038:8c00::/242038:8cff:ffff:ffff:ffff:ffff:ffff:ffff
1422038:8d00::/242038:8dff:ffff:ffff:ffff:ffff:ffff:ffff
1432038:8e00::/242038:8eff:ffff:ffff:ffff:ffff:ffff:ffff
1442038:8f00::/242038:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1452038:9000::/242038:90ff:ffff:ffff:ffff:ffff:ffff:ffff
1462038:9100::/242038:91ff:ffff:ffff:ffff:ffff:ffff:ffff
1472038:9200::/242038:92ff:ffff:ffff:ffff:ffff:ffff:ffff
1482038:9300::/242038:93ff:ffff:ffff:ffff:ffff:ffff:ffff
1492038:9400::/242038:94ff:ffff:ffff:ffff:ffff:ffff:ffff
1502038:9500::/242038:95ff:ffff:ffff:ffff:ffff:ffff:ffff
1512038:9600::/242038:96ff:ffff:ffff:ffff:ffff:ffff:ffff
1522038:9700::/242038:97ff:ffff:ffff:ffff:ffff:ffff:ffff
1532038:9800::/242038:98ff:ffff:ffff:ffff:ffff:ffff:ffff
1542038:9900::/242038:99ff:ffff:ffff:ffff:ffff:ffff:ffff
1552038:9a00::/242038:9aff:ffff:ffff:ffff:ffff:ffff:ffff
1562038:9b00::/242038:9bff:ffff:ffff:ffff:ffff:ffff:ffff
1572038:9c00::/242038:9cff:ffff:ffff:ffff:ffff:ffff:ffff
1582038:9d00::/242038:9dff:ffff:ffff:ffff:ffff:ffff:ffff
1592038:9e00::/242038:9eff:ffff:ffff:ffff:ffff:ffff:ffff
1602038:9f00::/242038:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1612038:a000::/242038:a0ff:ffff:ffff:ffff:ffff:ffff:ffff
1622038:a100::/242038:a1ff:ffff:ffff:ffff:ffff:ffff:ffff
1632038:a200::/242038:a2ff:ffff:ffff:ffff:ffff:ffff:ffff
1642038:a300::/242038:a3ff:ffff:ffff:ffff:ffff:ffff:ffff
1652038:a400::/242038:a4ff:ffff:ffff:ffff:ffff:ffff:ffff
1662038:a500::/242038:a5ff:ffff:ffff:ffff:ffff:ffff:ffff
1672038:a600::/242038:a6ff:ffff:ffff:ffff:ffff:ffff:ffff
1682038:a700::/242038:a7ff:ffff:ffff:ffff:ffff:ffff:ffff
1692038:a800::/242038:a8ff:ffff:ffff:ffff:ffff:ffff:ffff
1702038:a900::/242038:a9ff:ffff:ffff:ffff:ffff:ffff:ffff
1712038:aa00::/242038:aaff:ffff:ffff:ffff:ffff:ffff:ffff
1722038:ab00::/242038:abff:ffff:ffff:ffff:ffff:ffff:ffff
1732038:ac00::/242038:acff:ffff:ffff:ffff:ffff:ffff:ffff
1742038:ad00::/242038:adff:ffff:ffff:ffff:ffff:ffff:ffff
1752038:ae00::/242038:aeff:ffff:ffff:ffff:ffff:ffff:ffff
1762038:af00::/242038:afff:ffff:ffff:ffff:ffff:ffff:ffff
1772038:b000::/242038:b0ff:ffff:ffff:ffff:ffff:ffff:ffff
1782038:b100::/242038:b1ff:ffff:ffff:ffff:ffff:ffff:ffff
1792038:b200::/242038:b2ff:ffff:ffff:ffff:ffff:ffff:ffff
1802038:b300::/242038:b3ff:ffff:ffff:ffff:ffff:ffff:ffff
1812038:b400::/242038:b4ff:ffff:ffff:ffff:ffff:ffff:ffff
1822038:b500::/242038:b5ff:ffff:ffff:ffff:ffff:ffff:ffff
1832038:b600::/242038:b6ff:ffff:ffff:ffff:ffff:ffff:ffff
1842038:b700::/242038:b7ff:ffff:ffff:ffff:ffff:ffff:ffff
1852038:b800::/242038:b8ff:ffff:ffff:ffff:ffff:ffff:ffff
1862038:b900::/242038:b9ff:ffff:ffff:ffff:ffff:ffff:ffff
1872038:ba00::/242038:baff:ffff:ffff:ffff:ffff:ffff:ffff
1882038:bb00::/242038:bbff:ffff:ffff:ffff:ffff:ffff:ffff
1892038:bc00::/242038:bcff:ffff:ffff:ffff:ffff:ffff:ffff
1902038:bd00::/242038:bdff:ffff:ffff:ffff:ffff:ffff:ffff
1912038:be00::/242038:beff:ffff:ffff:ffff:ffff:ffff:ffff
1922038:bf00::/242038:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1932038:c000::/242038:c0ff:ffff:ffff:ffff:ffff:ffff:ffff
1942038:c100::/242038:c1ff:ffff:ffff:ffff:ffff:ffff:ffff
1952038:c200::/242038:c2ff:ffff:ffff:ffff:ffff:ffff:ffff
1962038:c300::/242038:c3ff:ffff:ffff:ffff:ffff:ffff:ffff
1972038:c400::/242038:c4ff:ffff:ffff:ffff:ffff:ffff:ffff
1982038:c500::/242038:c5ff:ffff:ffff:ffff:ffff:ffff:ffff
1992038:c600::/242038:c6ff:ffff:ffff:ffff:ffff:ffff:ffff
2002038:c700::/242038:c7ff:ffff:ffff:ffff:ffff:ffff:ffff
2012038:c800::/242038:c8ff:ffff:ffff:ffff:ffff:ffff:ffff
2022038:c900::/242038:c9ff:ffff:ffff:ffff:ffff:ffff:ffff
2032038:ca00::/242038:caff:ffff:ffff:ffff:ffff:ffff:ffff
2042038:cb00::/242038:cbff:ffff:ffff:ffff:ffff:ffff:ffff
2052038:cc00::/242038:ccff:ffff:ffff:ffff:ffff:ffff:ffff
2062038:cd00::/242038:cdff:ffff:ffff:ffff:ffff:ffff:ffff
2072038:ce00::/242038:ceff:ffff:ffff:ffff:ffff:ffff:ffff
2082038:cf00::/242038:cfff:ffff:ffff:ffff:ffff:ffff:ffff
2092038:d000::/242038:d0ff:ffff:ffff:ffff:ffff:ffff:ffff
2102038:d100::/242038:d1ff:ffff:ffff:ffff:ffff:ffff:ffff
2112038:d200::/242038:d2ff:ffff:ffff:ffff:ffff:ffff:ffff
2122038:d300::/242038:d3ff:ffff:ffff:ffff:ffff:ffff:ffff
2132038:d400::/242038:d4ff:ffff:ffff:ffff:ffff:ffff:ffff
2142038:d500::/242038:d5ff:ffff:ffff:ffff:ffff:ffff:ffff
2152038:d600::/242038:d6ff:ffff:ffff:ffff:ffff:ffff:ffff
2162038:d700::/242038:d7ff:ffff:ffff:ffff:ffff:ffff:ffff
2172038:d800::/242038:d8ff:ffff:ffff:ffff:ffff:ffff:ffff
2182038:d900::/242038:d9ff:ffff:ffff:ffff:ffff:ffff:ffff
2192038:da00::/242038:daff:ffff:ffff:ffff:ffff:ffff:ffff
2202038:db00::/242038:dbff:ffff:ffff:ffff:ffff:ffff:ffff
2212038:dc00::/242038:dcff:ffff:ffff:ffff:ffff:ffff:ffff
2222038:dd00::/242038:ddff:ffff:ffff:ffff:ffff:ffff:ffff
2232038:de00::/242038:deff:ffff:ffff:ffff:ffff:ffff:ffff
2242038:df00::/242038:dfff:ffff:ffff:ffff:ffff:ffff:ffff
2252038:e000::/242038:e0ff:ffff:ffff:ffff:ffff:ffff:ffff
2262038:e100::/242038:e1ff:ffff:ffff:ffff:ffff:ffff:ffff
2272038:e200::/242038:e2ff:ffff:ffff:ffff:ffff:ffff:ffff
2282038:e300::/242038:e3ff:ffff:ffff:ffff:ffff:ffff:ffff
2292038:e400::/242038:e4ff:ffff:ffff:ffff:ffff:ffff:ffff
2302038:e500::/242038:e5ff:ffff:ffff:ffff:ffff:ffff:ffff
2312038:e600::/242038:e6ff:ffff:ffff:ffff:ffff:ffff:ffff
2322038:e700::/242038:e7ff:ffff:ffff:ffff:ffff:ffff:ffff
2332038:e800::/242038:e8ff:ffff:ffff:ffff:ffff:ffff:ffff
2342038:e900::/242038:e9ff:ffff:ffff:ffff:ffff:ffff:ffff
2352038:ea00::/242038:eaff:ffff:ffff:ffff:ffff:ffff:ffff
2362038:eb00::/242038:ebff:ffff:ffff:ffff:ffff:ffff:ffff
2372038:ec00::/242038:ecff:ffff:ffff:ffff:ffff:ffff:ffff
2382038:ed00::/242038:edff:ffff:ffff:ffff:ffff:ffff:ffff
2392038:ee00::/242038:eeff:ffff:ffff:ffff:ffff:ffff:ffff
2402038:ef00::/242038:efff:ffff:ffff:ffff:ffff:ffff:ffff
2412038:f000::/242038:f0ff:ffff:ffff:ffff:ffff:ffff:ffff
2422038:f100::/242038:f1ff:ffff:ffff:ffff:ffff:ffff:ffff
2432038:f200::/242038:f2ff:ffff:ffff:ffff:ffff:ffff:ffff
2442038:f300::/242038:f3ff:ffff:ffff:ffff:ffff:ffff:ffff
2452038:f400::/242038:f4ff:ffff:ffff:ffff:ffff:ffff:ffff
2462038:f500::/242038:f5ff:ffff:ffff:ffff:ffff:ffff:ffff
2472038:f600::/242038:f6ff:ffff:ffff:ffff:ffff:ffff:ffff
2482038:f700::/242038:f7ff:ffff:ffff:ffff:ffff:ffff:ffff
2492038:f800::/242038:f8ff:ffff:ffff:ffff:ffff:ffff:ffff
2502038:f900::/242038:f9ff:ffff:ffff:ffff:ffff:ffff:ffff
2512038:fa00::/242038:faff:ffff:ffff:ffff:ffff:ffff:ffff
2522038:fb00::/242038:fbff:ffff:ffff:ffff:ffff:ffff:ffff
2532038:fc00::/242038:fcff:ffff:ffff:ffff:ffff:ffff:ffff
2542038:fd00::/242038:fdff:ffff:ffff:ffff:ffff:ffff:ffff
2552038:fe00::/242038:feff:ffff:ffff:ffff:ffff:ffff:ffff
2562038:ff00::/242038:ffff:ffff:ffff:ffff:ffff:ffff:ffff

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.