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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
2049::/16
First address
2049::
Last address
2049: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
2049:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
9.4.0.2.ip6.arpa
Split into smaller subnets/24
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

2049::/16 makes 256 subnets of /24.

Subnets
#SubnetLast address
12049::/242049:ff:ffff:ffff:ffff:ffff:ffff:ffff
22049:100::/242049:1ff:ffff:ffff:ffff:ffff:ffff:ffff
32049:200::/242049:2ff:ffff:ffff:ffff:ffff:ffff:ffff
42049:300::/242049:3ff:ffff:ffff:ffff:ffff:ffff:ffff
52049:400::/242049:4ff:ffff:ffff:ffff:ffff:ffff:ffff
62049:500::/242049:5ff:ffff:ffff:ffff:ffff:ffff:ffff
72049:600::/242049:6ff:ffff:ffff:ffff:ffff:ffff:ffff
82049:700::/242049:7ff:ffff:ffff:ffff:ffff:ffff:ffff
92049:800::/242049:8ff:ffff:ffff:ffff:ffff:ffff:ffff
102049:900::/242049:9ff:ffff:ffff:ffff:ffff:ffff:ffff
112049:a00::/242049:aff:ffff:ffff:ffff:ffff:ffff:ffff
122049:b00::/242049:bff:ffff:ffff:ffff:ffff:ffff:ffff
132049:c00::/242049:cff:ffff:ffff:ffff:ffff:ffff:ffff
142049:d00::/242049:dff:ffff:ffff:ffff:ffff:ffff:ffff
152049:e00::/242049:eff:ffff:ffff:ffff:ffff:ffff:ffff
162049:f00::/242049:fff:ffff:ffff:ffff:ffff:ffff:ffff
172049:1000::/242049:10ff:ffff:ffff:ffff:ffff:ffff:ffff
182049:1100::/242049:11ff:ffff:ffff:ffff:ffff:ffff:ffff
192049:1200::/242049:12ff:ffff:ffff:ffff:ffff:ffff:ffff
202049:1300::/242049:13ff:ffff:ffff:ffff:ffff:ffff:ffff
212049:1400::/242049:14ff:ffff:ffff:ffff:ffff:ffff:ffff
222049:1500::/242049:15ff:ffff:ffff:ffff:ffff:ffff:ffff
232049:1600::/242049:16ff:ffff:ffff:ffff:ffff:ffff:ffff
242049:1700::/242049:17ff:ffff:ffff:ffff:ffff:ffff:ffff
252049:1800::/242049:18ff:ffff:ffff:ffff:ffff:ffff:ffff
262049:1900::/242049:19ff:ffff:ffff:ffff:ffff:ffff:ffff
272049:1a00::/242049:1aff:ffff:ffff:ffff:ffff:ffff:ffff
282049:1b00::/242049:1bff:ffff:ffff:ffff:ffff:ffff:ffff
292049:1c00::/242049:1cff:ffff:ffff:ffff:ffff:ffff:ffff
302049:1d00::/242049:1dff:ffff:ffff:ffff:ffff:ffff:ffff
312049:1e00::/242049:1eff:ffff:ffff:ffff:ffff:ffff:ffff
322049:1f00::/242049:1fff:ffff:ffff:ffff:ffff:ffff:ffff
332049:2000::/242049:20ff:ffff:ffff:ffff:ffff:ffff:ffff
342049:2100::/242049:21ff:ffff:ffff:ffff:ffff:ffff:ffff
352049:2200::/242049:22ff:ffff:ffff:ffff:ffff:ffff:ffff
362049:2300::/242049:23ff:ffff:ffff:ffff:ffff:ffff:ffff
372049:2400::/242049:24ff:ffff:ffff:ffff:ffff:ffff:ffff
382049:2500::/242049:25ff:ffff:ffff:ffff:ffff:ffff:ffff
392049:2600::/242049:26ff:ffff:ffff:ffff:ffff:ffff:ffff
402049:2700::/242049:27ff:ffff:ffff:ffff:ffff:ffff:ffff
412049:2800::/242049:28ff:ffff:ffff:ffff:ffff:ffff:ffff
422049:2900::/242049:29ff:ffff:ffff:ffff:ffff:ffff:ffff
432049:2a00::/242049:2aff:ffff:ffff:ffff:ffff:ffff:ffff
442049:2b00::/242049:2bff:ffff:ffff:ffff:ffff:ffff:ffff
452049:2c00::/242049:2cff:ffff:ffff:ffff:ffff:ffff:ffff
462049:2d00::/242049:2dff:ffff:ffff:ffff:ffff:ffff:ffff
472049:2e00::/242049:2eff:ffff:ffff:ffff:ffff:ffff:ffff
482049:2f00::/242049:2fff:ffff:ffff:ffff:ffff:ffff:ffff
492049:3000::/242049:30ff:ffff:ffff:ffff:ffff:ffff:ffff
502049:3100::/242049:31ff:ffff:ffff:ffff:ffff:ffff:ffff
512049:3200::/242049:32ff:ffff:ffff:ffff:ffff:ffff:ffff
522049:3300::/242049:33ff:ffff:ffff:ffff:ffff:ffff:ffff
532049:3400::/242049:34ff:ffff:ffff:ffff:ffff:ffff:ffff
542049:3500::/242049:35ff:ffff:ffff:ffff:ffff:ffff:ffff
552049:3600::/242049:36ff:ffff:ffff:ffff:ffff:ffff:ffff
562049:3700::/242049:37ff:ffff:ffff:ffff:ffff:ffff:ffff
572049:3800::/242049:38ff:ffff:ffff:ffff:ffff:ffff:ffff
582049:3900::/242049:39ff:ffff:ffff:ffff:ffff:ffff:ffff
592049:3a00::/242049:3aff:ffff:ffff:ffff:ffff:ffff:ffff
602049:3b00::/242049:3bff:ffff:ffff:ffff:ffff:ffff:ffff
612049:3c00::/242049:3cff:ffff:ffff:ffff:ffff:ffff:ffff
622049:3d00::/242049:3dff:ffff:ffff:ffff:ffff:ffff:ffff
632049:3e00::/242049:3eff:ffff:ffff:ffff:ffff:ffff:ffff
642049:3f00::/242049:3fff:ffff:ffff:ffff:ffff:ffff:ffff
652049:4000::/242049:40ff:ffff:ffff:ffff:ffff:ffff:ffff
662049:4100::/242049:41ff:ffff:ffff:ffff:ffff:ffff:ffff
672049:4200::/242049:42ff:ffff:ffff:ffff:ffff:ffff:ffff
682049:4300::/242049:43ff:ffff:ffff:ffff:ffff:ffff:ffff
692049:4400::/242049:44ff:ffff:ffff:ffff:ffff:ffff:ffff
702049:4500::/242049:45ff:ffff:ffff:ffff:ffff:ffff:ffff
712049:4600::/242049:46ff:ffff:ffff:ffff:ffff:ffff:ffff
722049:4700::/242049:47ff:ffff:ffff:ffff:ffff:ffff:ffff
732049:4800::/242049:48ff:ffff:ffff:ffff:ffff:ffff:ffff
742049:4900::/242049:49ff:ffff:ffff:ffff:ffff:ffff:ffff
752049:4a00::/242049:4aff:ffff:ffff:ffff:ffff:ffff:ffff
762049:4b00::/242049:4bff:ffff:ffff:ffff:ffff:ffff:ffff
772049:4c00::/242049:4cff:ffff:ffff:ffff:ffff:ffff:ffff
782049:4d00::/242049:4dff:ffff:ffff:ffff:ffff:ffff:ffff
792049:4e00::/242049:4eff:ffff:ffff:ffff:ffff:ffff:ffff
802049:4f00::/242049:4fff:ffff:ffff:ffff:ffff:ffff:ffff
812049:5000::/242049:50ff:ffff:ffff:ffff:ffff:ffff:ffff
822049:5100::/242049:51ff:ffff:ffff:ffff:ffff:ffff:ffff
832049:5200::/242049:52ff:ffff:ffff:ffff:ffff:ffff:ffff
842049:5300::/242049:53ff:ffff:ffff:ffff:ffff:ffff:ffff
852049:5400::/242049:54ff:ffff:ffff:ffff:ffff:ffff:ffff
862049:5500::/242049:55ff:ffff:ffff:ffff:ffff:ffff:ffff
872049:5600::/242049:56ff:ffff:ffff:ffff:ffff:ffff:ffff
882049:5700::/242049:57ff:ffff:ffff:ffff:ffff:ffff:ffff
892049:5800::/242049:58ff:ffff:ffff:ffff:ffff:ffff:ffff
902049:5900::/242049:59ff:ffff:ffff:ffff:ffff:ffff:ffff
912049:5a00::/242049:5aff:ffff:ffff:ffff:ffff:ffff:ffff
922049:5b00::/242049:5bff:ffff:ffff:ffff:ffff:ffff:ffff
932049:5c00::/242049:5cff:ffff:ffff:ffff:ffff:ffff:ffff
942049:5d00::/242049:5dff:ffff:ffff:ffff:ffff:ffff:ffff
952049:5e00::/242049:5eff:ffff:ffff:ffff:ffff:ffff:ffff
962049:5f00::/242049:5fff:ffff:ffff:ffff:ffff:ffff:ffff
972049:6000::/242049:60ff:ffff:ffff:ffff:ffff:ffff:ffff
982049:6100::/242049:61ff:ffff:ffff:ffff:ffff:ffff:ffff
992049:6200::/242049:62ff:ffff:ffff:ffff:ffff:ffff:ffff
1002049:6300::/242049:63ff:ffff:ffff:ffff:ffff:ffff:ffff
1012049:6400::/242049:64ff:ffff:ffff:ffff:ffff:ffff:ffff
1022049:6500::/242049:65ff:ffff:ffff:ffff:ffff:ffff:ffff
1032049:6600::/242049:66ff:ffff:ffff:ffff:ffff:ffff:ffff
1042049:6700::/242049:67ff:ffff:ffff:ffff:ffff:ffff:ffff
1052049:6800::/242049:68ff:ffff:ffff:ffff:ffff:ffff:ffff
1062049:6900::/242049:69ff:ffff:ffff:ffff:ffff:ffff:ffff
1072049:6a00::/242049:6aff:ffff:ffff:ffff:ffff:ffff:ffff
1082049:6b00::/242049:6bff:ffff:ffff:ffff:ffff:ffff:ffff
1092049:6c00::/242049:6cff:ffff:ffff:ffff:ffff:ffff:ffff
1102049:6d00::/242049:6dff:ffff:ffff:ffff:ffff:ffff:ffff
1112049:6e00::/242049:6eff:ffff:ffff:ffff:ffff:ffff:ffff
1122049:6f00::/242049:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1132049:7000::/242049:70ff:ffff:ffff:ffff:ffff:ffff:ffff
1142049:7100::/242049:71ff:ffff:ffff:ffff:ffff:ffff:ffff
1152049:7200::/242049:72ff:ffff:ffff:ffff:ffff:ffff:ffff
1162049:7300::/242049:73ff:ffff:ffff:ffff:ffff:ffff:ffff
1172049:7400::/242049:74ff:ffff:ffff:ffff:ffff:ffff:ffff
1182049:7500::/242049:75ff:ffff:ffff:ffff:ffff:ffff:ffff
1192049:7600::/242049:76ff:ffff:ffff:ffff:ffff:ffff:ffff
1202049:7700::/242049:77ff:ffff:ffff:ffff:ffff:ffff:ffff
1212049:7800::/242049:78ff:ffff:ffff:ffff:ffff:ffff:ffff
1222049:7900::/242049:79ff:ffff:ffff:ffff:ffff:ffff:ffff
1232049:7a00::/242049:7aff:ffff:ffff:ffff:ffff:ffff:ffff
1242049:7b00::/242049:7bff:ffff:ffff:ffff:ffff:ffff:ffff
1252049:7c00::/242049:7cff:ffff:ffff:ffff:ffff:ffff:ffff
1262049:7d00::/242049:7dff:ffff:ffff:ffff:ffff:ffff:ffff
1272049:7e00::/242049:7eff:ffff:ffff:ffff:ffff:ffff:ffff
1282049:7f00::/242049:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1292049:8000::/242049:80ff:ffff:ffff:ffff:ffff:ffff:ffff
1302049:8100::/242049:81ff:ffff:ffff:ffff:ffff:ffff:ffff
1312049:8200::/242049:82ff:ffff:ffff:ffff:ffff:ffff:ffff
1322049:8300::/242049:83ff:ffff:ffff:ffff:ffff:ffff:ffff
1332049:8400::/242049:84ff:ffff:ffff:ffff:ffff:ffff:ffff
1342049:8500::/242049:85ff:ffff:ffff:ffff:ffff:ffff:ffff
1352049:8600::/242049:86ff:ffff:ffff:ffff:ffff:ffff:ffff
1362049:8700::/242049:87ff:ffff:ffff:ffff:ffff:ffff:ffff
1372049:8800::/242049:88ff:ffff:ffff:ffff:ffff:ffff:ffff
1382049:8900::/242049:89ff:ffff:ffff:ffff:ffff:ffff:ffff
1392049:8a00::/242049:8aff:ffff:ffff:ffff:ffff:ffff:ffff
1402049:8b00::/242049:8bff:ffff:ffff:ffff:ffff:ffff:ffff
1412049:8c00::/242049:8cff:ffff:ffff:ffff:ffff:ffff:ffff
1422049:8d00::/242049:8dff:ffff:ffff:ffff:ffff:ffff:ffff
1432049:8e00::/242049:8eff:ffff:ffff:ffff:ffff:ffff:ffff
1442049:8f00::/242049:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1452049:9000::/242049:90ff:ffff:ffff:ffff:ffff:ffff:ffff
1462049:9100::/242049:91ff:ffff:ffff:ffff:ffff:ffff:ffff
1472049:9200::/242049:92ff:ffff:ffff:ffff:ffff:ffff:ffff
1482049:9300::/242049:93ff:ffff:ffff:ffff:ffff:ffff:ffff
1492049:9400::/242049:94ff:ffff:ffff:ffff:ffff:ffff:ffff
1502049:9500::/242049:95ff:ffff:ffff:ffff:ffff:ffff:ffff
1512049:9600::/242049:96ff:ffff:ffff:ffff:ffff:ffff:ffff
1522049:9700::/242049:97ff:ffff:ffff:ffff:ffff:ffff:ffff
1532049:9800::/242049:98ff:ffff:ffff:ffff:ffff:ffff:ffff
1542049:9900::/242049:99ff:ffff:ffff:ffff:ffff:ffff:ffff
1552049:9a00::/242049:9aff:ffff:ffff:ffff:ffff:ffff:ffff
1562049:9b00::/242049:9bff:ffff:ffff:ffff:ffff:ffff:ffff
1572049:9c00::/242049:9cff:ffff:ffff:ffff:ffff:ffff:ffff
1582049:9d00::/242049:9dff:ffff:ffff:ffff:ffff:ffff:ffff
1592049:9e00::/242049:9eff:ffff:ffff:ffff:ffff:ffff:ffff
1602049:9f00::/242049:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1612049:a000::/242049:a0ff:ffff:ffff:ffff:ffff:ffff:ffff
1622049:a100::/242049:a1ff:ffff:ffff:ffff:ffff:ffff:ffff
1632049:a200::/242049:a2ff:ffff:ffff:ffff:ffff:ffff:ffff
1642049:a300::/242049:a3ff:ffff:ffff:ffff:ffff:ffff:ffff
1652049:a400::/242049:a4ff:ffff:ffff:ffff:ffff:ffff:ffff
1662049:a500::/242049:a5ff:ffff:ffff:ffff:ffff:ffff:ffff
1672049:a600::/242049:a6ff:ffff:ffff:ffff:ffff:ffff:ffff
1682049:a700::/242049:a7ff:ffff:ffff:ffff:ffff:ffff:ffff
1692049:a800::/242049:a8ff:ffff:ffff:ffff:ffff:ffff:ffff
1702049:a900::/242049:a9ff:ffff:ffff:ffff:ffff:ffff:ffff
1712049:aa00::/242049:aaff:ffff:ffff:ffff:ffff:ffff:ffff
1722049:ab00::/242049:abff:ffff:ffff:ffff:ffff:ffff:ffff
1732049:ac00::/242049:acff:ffff:ffff:ffff:ffff:ffff:ffff
1742049:ad00::/242049:adff:ffff:ffff:ffff:ffff:ffff:ffff
1752049:ae00::/242049:aeff:ffff:ffff:ffff:ffff:ffff:ffff
1762049:af00::/242049:afff:ffff:ffff:ffff:ffff:ffff:ffff
1772049:b000::/242049:b0ff:ffff:ffff:ffff:ffff:ffff:ffff
1782049:b100::/242049:b1ff:ffff:ffff:ffff:ffff:ffff:ffff
1792049:b200::/242049:b2ff:ffff:ffff:ffff:ffff:ffff:ffff
1802049:b300::/242049:b3ff:ffff:ffff:ffff:ffff:ffff:ffff
1812049:b400::/242049:b4ff:ffff:ffff:ffff:ffff:ffff:ffff
1822049:b500::/242049:b5ff:ffff:ffff:ffff:ffff:ffff:ffff
1832049:b600::/242049:b6ff:ffff:ffff:ffff:ffff:ffff:ffff
1842049:b700::/242049:b7ff:ffff:ffff:ffff:ffff:ffff:ffff
1852049:b800::/242049:b8ff:ffff:ffff:ffff:ffff:ffff:ffff
1862049:b900::/242049:b9ff:ffff:ffff:ffff:ffff:ffff:ffff
1872049:ba00::/242049:baff:ffff:ffff:ffff:ffff:ffff:ffff
1882049:bb00::/242049:bbff:ffff:ffff:ffff:ffff:ffff:ffff
1892049:bc00::/242049:bcff:ffff:ffff:ffff:ffff:ffff:ffff
1902049:bd00::/242049:bdff:ffff:ffff:ffff:ffff:ffff:ffff
1912049:be00::/242049:beff:ffff:ffff:ffff:ffff:ffff:ffff
1922049:bf00::/242049:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1932049:c000::/242049:c0ff:ffff:ffff:ffff:ffff:ffff:ffff
1942049:c100::/242049:c1ff:ffff:ffff:ffff:ffff:ffff:ffff
1952049:c200::/242049:c2ff:ffff:ffff:ffff:ffff:ffff:ffff
1962049:c300::/242049:c3ff:ffff:ffff:ffff:ffff:ffff:ffff
1972049:c400::/242049:c4ff:ffff:ffff:ffff:ffff:ffff:ffff
1982049:c500::/242049:c5ff:ffff:ffff:ffff:ffff:ffff:ffff
1992049:c600::/242049:c6ff:ffff:ffff:ffff:ffff:ffff:ffff
2002049:c700::/242049:c7ff:ffff:ffff:ffff:ffff:ffff:ffff
2012049:c800::/242049:c8ff:ffff:ffff:ffff:ffff:ffff:ffff
2022049:c900::/242049:c9ff:ffff:ffff:ffff:ffff:ffff:ffff
2032049:ca00::/242049:caff:ffff:ffff:ffff:ffff:ffff:ffff
2042049:cb00::/242049:cbff:ffff:ffff:ffff:ffff:ffff:ffff
2052049:cc00::/242049:ccff:ffff:ffff:ffff:ffff:ffff:ffff
2062049:cd00::/242049:cdff:ffff:ffff:ffff:ffff:ffff:ffff
2072049:ce00::/242049:ceff:ffff:ffff:ffff:ffff:ffff:ffff
2082049:cf00::/242049:cfff:ffff:ffff:ffff:ffff:ffff:ffff
2092049:d000::/242049:d0ff:ffff:ffff:ffff:ffff:ffff:ffff
2102049:d100::/242049:d1ff:ffff:ffff:ffff:ffff:ffff:ffff
2112049:d200::/242049:d2ff:ffff:ffff:ffff:ffff:ffff:ffff
2122049:d300::/242049:d3ff:ffff:ffff:ffff:ffff:ffff:ffff
2132049:d400::/242049:d4ff:ffff:ffff:ffff:ffff:ffff:ffff
2142049:d500::/242049:d5ff:ffff:ffff:ffff:ffff:ffff:ffff
2152049:d600::/242049:d6ff:ffff:ffff:ffff:ffff:ffff:ffff
2162049:d700::/242049:d7ff:ffff:ffff:ffff:ffff:ffff:ffff
2172049:d800::/242049:d8ff:ffff:ffff:ffff:ffff:ffff:ffff
2182049:d900::/242049:d9ff:ffff:ffff:ffff:ffff:ffff:ffff
2192049:da00::/242049:daff:ffff:ffff:ffff:ffff:ffff:ffff
2202049:db00::/242049:dbff:ffff:ffff:ffff:ffff:ffff:ffff
2212049:dc00::/242049:dcff:ffff:ffff:ffff:ffff:ffff:ffff
2222049:dd00::/242049:ddff:ffff:ffff:ffff:ffff:ffff:ffff
2232049:de00::/242049:deff:ffff:ffff:ffff:ffff:ffff:ffff
2242049:df00::/242049:dfff:ffff:ffff:ffff:ffff:ffff:ffff
2252049:e000::/242049:e0ff:ffff:ffff:ffff:ffff:ffff:ffff
2262049:e100::/242049:e1ff:ffff:ffff:ffff:ffff:ffff:ffff
2272049:e200::/242049:e2ff:ffff:ffff:ffff:ffff:ffff:ffff
2282049:e300::/242049:e3ff:ffff:ffff:ffff:ffff:ffff:ffff
2292049:e400::/242049:e4ff:ffff:ffff:ffff:ffff:ffff:ffff
2302049:e500::/242049:e5ff:ffff:ffff:ffff:ffff:ffff:ffff
2312049:e600::/242049:e6ff:ffff:ffff:ffff:ffff:ffff:ffff
2322049:e700::/242049:e7ff:ffff:ffff:ffff:ffff:ffff:ffff
2332049:e800::/242049:e8ff:ffff:ffff:ffff:ffff:ffff:ffff
2342049:e900::/242049:e9ff:ffff:ffff:ffff:ffff:ffff:ffff
2352049:ea00::/242049:eaff:ffff:ffff:ffff:ffff:ffff:ffff
2362049:eb00::/242049:ebff:ffff:ffff:ffff:ffff:ffff:ffff
2372049:ec00::/242049:ecff:ffff:ffff:ffff:ffff:ffff:ffff
2382049:ed00::/242049:edff:ffff:ffff:ffff:ffff:ffff:ffff
2392049:ee00::/242049:eeff:ffff:ffff:ffff:ffff:ffff:ffff
2402049:ef00::/242049:efff:ffff:ffff:ffff:ffff:ffff:ffff
2412049:f000::/242049:f0ff:ffff:ffff:ffff:ffff:ffff:ffff
2422049:f100::/242049:f1ff:ffff:ffff:ffff:ffff:ffff:ffff
2432049:f200::/242049:f2ff:ffff:ffff:ffff:ffff:ffff:ffff
2442049:f300::/242049:f3ff:ffff:ffff:ffff:ffff:ffff:ffff
2452049:f400::/242049:f4ff:ffff:ffff:ffff:ffff:ffff:ffff
2462049:f500::/242049:f5ff:ffff:ffff:ffff:ffff:ffff:ffff
2472049:f600::/242049:f6ff:ffff:ffff:ffff:ffff:ffff:ffff
2482049:f700::/242049:f7ff:ffff:ffff:ffff:ffff:ffff:ffff
2492049:f800::/242049:f8ff:ffff:ffff:ffff:ffff:ffff:ffff
2502049:f900::/242049:f9ff:ffff:ffff:ffff:ffff:ffff:ffff
2512049:fa00::/242049:faff:ffff:ffff:ffff:ffff:ffff:ffff
2522049:fb00::/242049:fbff:ffff:ffff:ffff:ffff:ffff:ffff
2532049:fc00::/242049:fcff:ffff:ffff:ffff:ffff:ffff:ffff
2542049:fd00::/242049:fdff:ffff:ffff:ffff:ffff:ffff:ffff
2552049:fe00::/242049:feff:ffff:ffff:ffff:ffff:ffff:ffff
2562049:ff00::/242049: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.