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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/104
Addresses16,777,216
/64 networksPart of one
Network
2001:db8::9700:7500:0/104
First address
2001:db8::9700:7500:0
Last address
2001:db8::9700:75ff:ffff
Addresses
16,777,216
/64 networks (LANs)
None: smaller than one /64 LAN
Full form
2001:0db8:0000:0000:0000:9700:7500:0000
Type
Documentation 2001:db8::/32
For examples; never used on a network
Reverse DNS zone
5.7.0.0.7.9.0.0.0.0.0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa
Split into smaller subnets/120
/105 (2)/106 (4)/107 (8)/108 (16)/112 (256)/116 (4,096)/120 (65,536)

2001:db8::9700:7500:0/104 makes 65,536 subnets of /120; the first 256 are listed.

Subnets
#SubnetLast address
12001:db8::9700:7500:0/1202001:db8::9700:7500:ff
22001:db8::9700:7500:100/1202001:db8::9700:7500:1ff
32001:db8::9700:7500:200/1202001:db8::9700:7500:2ff
42001:db8::9700:7500:300/1202001:db8::9700:7500:3ff
52001:db8::9700:7500:400/1202001:db8::9700:7500:4ff
62001:db8::9700:7500:500/1202001:db8::9700:7500:5ff
72001:db8::9700:7500:600/1202001:db8::9700:7500:6ff
82001:db8::9700:7500:700/1202001:db8::9700:7500:7ff
92001:db8::9700:7500:800/1202001:db8::9700:7500:8ff
102001:db8::9700:7500:900/1202001:db8::9700:7500:9ff
112001:db8::9700:7500:a00/1202001:db8::9700:7500:aff
122001:db8::9700:7500:b00/1202001:db8::9700:7500:bff
132001:db8::9700:7500:c00/1202001:db8::9700:7500:cff
142001:db8::9700:7500:d00/1202001:db8::9700:7500:dff
152001:db8::9700:7500:e00/1202001:db8::9700:7500:eff
162001:db8::9700:7500:f00/1202001:db8::9700:7500:fff
172001:db8::9700:7500:1000/1202001:db8::9700:7500:10ff
182001:db8::9700:7500:1100/1202001:db8::9700:7500:11ff
192001:db8::9700:7500:1200/1202001:db8::9700:7500:12ff
202001:db8::9700:7500:1300/1202001:db8::9700:7500:13ff
212001:db8::9700:7500:1400/1202001:db8::9700:7500:14ff
222001:db8::9700:7500:1500/1202001:db8::9700:7500:15ff
232001:db8::9700:7500:1600/1202001:db8::9700:7500:16ff
242001:db8::9700:7500:1700/1202001:db8::9700:7500:17ff
252001:db8::9700:7500:1800/1202001:db8::9700:7500:18ff
262001:db8::9700:7500:1900/1202001:db8::9700:7500:19ff
272001:db8::9700:7500:1a00/1202001:db8::9700:7500:1aff
282001:db8::9700:7500:1b00/1202001:db8::9700:7500:1bff
292001:db8::9700:7500:1c00/1202001:db8::9700:7500:1cff
302001:db8::9700:7500:1d00/1202001:db8::9700:7500:1dff
312001:db8::9700:7500:1e00/1202001:db8::9700:7500:1eff
322001:db8::9700:7500:1f00/1202001:db8::9700:7500:1fff
332001:db8::9700:7500:2000/1202001:db8::9700:7500:20ff
342001:db8::9700:7500:2100/1202001:db8::9700:7500:21ff
352001:db8::9700:7500:2200/1202001:db8::9700:7500:22ff
362001:db8::9700:7500:2300/1202001:db8::9700:7500:23ff
372001:db8::9700:7500:2400/1202001:db8::9700:7500:24ff
382001:db8::9700:7500:2500/1202001:db8::9700:7500:25ff
392001:db8::9700:7500:2600/1202001:db8::9700:7500:26ff
402001:db8::9700:7500:2700/1202001:db8::9700:7500:27ff
412001:db8::9700:7500:2800/1202001:db8::9700:7500:28ff
422001:db8::9700:7500:2900/1202001:db8::9700:7500:29ff
432001:db8::9700:7500:2a00/1202001:db8::9700:7500:2aff
442001:db8::9700:7500:2b00/1202001:db8::9700:7500:2bff
452001:db8::9700:7500:2c00/1202001:db8::9700:7500:2cff
462001:db8::9700:7500:2d00/1202001:db8::9700:7500:2dff
472001:db8::9700:7500:2e00/1202001:db8::9700:7500:2eff
482001:db8::9700:7500:2f00/1202001:db8::9700:7500:2fff
492001:db8::9700:7500:3000/1202001:db8::9700:7500:30ff
502001:db8::9700:7500:3100/1202001:db8::9700:7500:31ff
512001:db8::9700:7500:3200/1202001:db8::9700:7500:32ff
522001:db8::9700:7500:3300/1202001:db8::9700:7500:33ff
532001:db8::9700:7500:3400/1202001:db8::9700:7500:34ff
542001:db8::9700:7500:3500/1202001:db8::9700:7500:35ff
552001:db8::9700:7500:3600/1202001:db8::9700:7500:36ff
562001:db8::9700:7500:3700/1202001:db8::9700:7500:37ff
572001:db8::9700:7500:3800/1202001:db8::9700:7500:38ff
582001:db8::9700:7500:3900/1202001:db8::9700:7500:39ff
592001:db8::9700:7500:3a00/1202001:db8::9700:7500:3aff
602001:db8::9700:7500:3b00/1202001:db8::9700:7500:3bff
612001:db8::9700:7500:3c00/1202001:db8::9700:7500:3cff
622001:db8::9700:7500:3d00/1202001:db8::9700:7500:3dff
632001:db8::9700:7500:3e00/1202001:db8::9700:7500:3eff
642001:db8::9700:7500:3f00/1202001:db8::9700:7500:3fff
652001:db8::9700:7500:4000/1202001:db8::9700:7500:40ff
662001:db8::9700:7500:4100/1202001:db8::9700:7500:41ff
672001:db8::9700:7500:4200/1202001:db8::9700:7500:42ff
682001:db8::9700:7500:4300/1202001:db8::9700:7500:43ff
692001:db8::9700:7500:4400/1202001:db8::9700:7500:44ff
702001:db8::9700:7500:4500/1202001:db8::9700:7500:45ff
712001:db8::9700:7500:4600/1202001:db8::9700:7500:46ff
722001:db8::9700:7500:4700/1202001:db8::9700:7500:47ff
732001:db8::9700:7500:4800/1202001:db8::9700:7500:48ff
742001:db8::9700:7500:4900/1202001:db8::9700:7500:49ff
752001:db8::9700:7500:4a00/1202001:db8::9700:7500:4aff
762001:db8::9700:7500:4b00/1202001:db8::9700:7500:4bff
772001:db8::9700:7500:4c00/1202001:db8::9700:7500:4cff
782001:db8::9700:7500:4d00/1202001:db8::9700:7500:4dff
792001:db8::9700:7500:4e00/1202001:db8::9700:7500:4eff
802001:db8::9700:7500:4f00/1202001:db8::9700:7500:4fff
812001:db8::9700:7500:5000/1202001:db8::9700:7500:50ff
822001:db8::9700:7500:5100/1202001:db8::9700:7500:51ff
832001:db8::9700:7500:5200/1202001:db8::9700:7500:52ff
842001:db8::9700:7500:5300/1202001:db8::9700:7500:53ff
852001:db8::9700:7500:5400/1202001:db8::9700:7500:54ff
862001:db8::9700:7500:5500/1202001:db8::9700:7500:55ff
872001:db8::9700:7500:5600/1202001:db8::9700:7500:56ff
882001:db8::9700:7500:5700/1202001:db8::9700:7500:57ff
892001:db8::9700:7500:5800/1202001:db8::9700:7500:58ff
902001:db8::9700:7500:5900/1202001:db8::9700:7500:59ff
912001:db8::9700:7500:5a00/1202001:db8::9700:7500:5aff
922001:db8::9700:7500:5b00/1202001:db8::9700:7500:5bff
932001:db8::9700:7500:5c00/1202001:db8::9700:7500:5cff
942001:db8::9700:7500:5d00/1202001:db8::9700:7500:5dff
952001:db8::9700:7500:5e00/1202001:db8::9700:7500:5eff
962001:db8::9700:7500:5f00/1202001:db8::9700:7500:5fff
972001:db8::9700:7500:6000/1202001:db8::9700:7500:60ff
982001:db8::9700:7500:6100/1202001:db8::9700:7500:61ff
992001:db8::9700:7500:6200/1202001:db8::9700:7500:62ff
1002001:db8::9700:7500:6300/1202001:db8::9700:7500:63ff
1012001:db8::9700:7500:6400/1202001:db8::9700:7500:64ff
1022001:db8::9700:7500:6500/1202001:db8::9700:7500:65ff
1032001:db8::9700:7500:6600/1202001:db8::9700:7500:66ff
1042001:db8::9700:7500:6700/1202001:db8::9700:7500:67ff
1052001:db8::9700:7500:6800/1202001:db8::9700:7500:68ff
1062001:db8::9700:7500:6900/1202001:db8::9700:7500:69ff
1072001:db8::9700:7500:6a00/1202001:db8::9700:7500:6aff
1082001:db8::9700:7500:6b00/1202001:db8::9700:7500:6bff
1092001:db8::9700:7500:6c00/1202001:db8::9700:7500:6cff
1102001:db8::9700:7500:6d00/1202001:db8::9700:7500:6dff
1112001:db8::9700:7500:6e00/1202001:db8::9700:7500:6eff
1122001:db8::9700:7500:6f00/1202001:db8::9700:7500:6fff
1132001:db8::9700:7500:7000/1202001:db8::9700:7500:70ff
1142001:db8::9700:7500:7100/1202001:db8::9700:7500:71ff
1152001:db8::9700:7500:7200/1202001:db8::9700:7500:72ff
1162001:db8::9700:7500:7300/1202001:db8::9700:7500:73ff
1172001:db8::9700:7500:7400/1202001:db8::9700:7500:74ff
1182001:db8::9700:7500:7500/1202001:db8::9700:7500:75ff
1192001:db8::9700:7500:7600/1202001:db8::9700:7500:76ff
1202001:db8::9700:7500:7700/1202001:db8::9700:7500:77ff
1212001:db8::9700:7500:7800/1202001:db8::9700:7500:78ff
1222001:db8::9700:7500:7900/1202001:db8::9700:7500:79ff
1232001:db8::9700:7500:7a00/1202001:db8::9700:7500:7aff
1242001:db8::9700:7500:7b00/1202001:db8::9700:7500:7bff
1252001:db8::9700:7500:7c00/1202001:db8::9700:7500:7cff
1262001:db8::9700:7500:7d00/1202001:db8::9700:7500:7dff
1272001:db8::9700:7500:7e00/1202001:db8::9700:7500:7eff
1282001:db8::9700:7500:7f00/1202001:db8::9700:7500:7fff
1292001:db8::9700:7500:8000/1202001:db8::9700:7500:80ff
1302001:db8::9700:7500:8100/1202001:db8::9700:7500:81ff
1312001:db8::9700:7500:8200/1202001:db8::9700:7500:82ff
1322001:db8::9700:7500:8300/1202001:db8::9700:7500:83ff
1332001:db8::9700:7500:8400/1202001:db8::9700:7500:84ff
1342001:db8::9700:7500:8500/1202001:db8::9700:7500:85ff
1352001:db8::9700:7500:8600/1202001:db8::9700:7500:86ff
1362001:db8::9700:7500:8700/1202001:db8::9700:7500:87ff
1372001:db8::9700:7500:8800/1202001:db8::9700:7500:88ff
1382001:db8::9700:7500:8900/1202001:db8::9700:7500:89ff
1392001:db8::9700:7500:8a00/1202001:db8::9700:7500:8aff
1402001:db8::9700:7500:8b00/1202001:db8::9700:7500:8bff
1412001:db8::9700:7500:8c00/1202001:db8::9700:7500:8cff
1422001:db8::9700:7500:8d00/1202001:db8::9700:7500:8dff
1432001:db8::9700:7500:8e00/1202001:db8::9700:7500:8eff
1442001:db8::9700:7500:8f00/1202001:db8::9700:7500:8fff
1452001:db8::9700:7500:9000/1202001:db8::9700:7500:90ff
1462001:db8::9700:7500:9100/1202001:db8::9700:7500:91ff
1472001:db8::9700:7500:9200/1202001:db8::9700:7500:92ff
1482001:db8::9700:7500:9300/1202001:db8::9700:7500:93ff
1492001:db8::9700:7500:9400/1202001:db8::9700:7500:94ff
1502001:db8::9700:7500:9500/1202001:db8::9700:7500:95ff
1512001:db8::9700:7500:9600/1202001:db8::9700:7500:96ff
1522001:db8::9700:7500:9700/1202001:db8::9700:7500:97ff
1532001:db8::9700:7500:9800/1202001:db8::9700:7500:98ff
1542001:db8::9700:7500:9900/1202001:db8::9700:7500:99ff
1552001:db8::9700:7500:9a00/1202001:db8::9700:7500:9aff
1562001:db8::9700:7500:9b00/1202001:db8::9700:7500:9bff
1572001:db8::9700:7500:9c00/1202001:db8::9700:7500:9cff
1582001:db8::9700:7500:9d00/1202001:db8::9700:7500:9dff
1592001:db8::9700:7500:9e00/1202001:db8::9700:7500:9eff
1602001:db8::9700:7500:9f00/1202001:db8::9700:7500:9fff
1612001:db8::9700:7500:a000/1202001:db8::9700:7500:a0ff
1622001:db8::9700:7500:a100/1202001:db8::9700:7500:a1ff
1632001:db8::9700:7500:a200/1202001:db8::9700:7500:a2ff
1642001:db8::9700:7500:a300/1202001:db8::9700:7500:a3ff
1652001:db8::9700:7500:a400/1202001:db8::9700:7500:a4ff
1662001:db8::9700:7500:a500/1202001:db8::9700:7500:a5ff
1672001:db8::9700:7500:a600/1202001:db8::9700:7500:a6ff
1682001:db8::9700:7500:a700/1202001:db8::9700:7500:a7ff
1692001:db8::9700:7500:a800/1202001:db8::9700:7500:a8ff
1702001:db8::9700:7500:a900/1202001:db8::9700:7500:a9ff
1712001:db8::9700:7500:aa00/1202001:db8::9700:7500:aaff
1722001:db8::9700:7500:ab00/1202001:db8::9700:7500:abff
1732001:db8::9700:7500:ac00/1202001:db8::9700:7500:acff
1742001:db8::9700:7500:ad00/1202001:db8::9700:7500:adff
1752001:db8::9700:7500:ae00/1202001:db8::9700:7500:aeff
1762001:db8::9700:7500:af00/1202001:db8::9700:7500:afff
1772001:db8::9700:7500:b000/1202001:db8::9700:7500:b0ff
1782001:db8::9700:7500:b100/1202001:db8::9700:7500:b1ff
1792001:db8::9700:7500:b200/1202001:db8::9700:7500:b2ff
1802001:db8::9700:7500:b300/1202001:db8::9700:7500:b3ff
1812001:db8::9700:7500:b400/1202001:db8::9700:7500:b4ff
1822001:db8::9700:7500:b500/1202001:db8::9700:7500:b5ff
1832001:db8::9700:7500:b600/1202001:db8::9700:7500:b6ff
1842001:db8::9700:7500:b700/1202001:db8::9700:7500:b7ff
1852001:db8::9700:7500:b800/1202001:db8::9700:7500:b8ff
1862001:db8::9700:7500:b900/1202001:db8::9700:7500:b9ff
1872001:db8::9700:7500:ba00/1202001:db8::9700:7500:baff
1882001:db8::9700:7500:bb00/1202001:db8::9700:7500:bbff
1892001:db8::9700:7500:bc00/1202001:db8::9700:7500:bcff
1902001:db8::9700:7500:bd00/1202001:db8::9700:7500:bdff
1912001:db8::9700:7500:be00/1202001:db8::9700:7500:beff
1922001:db8::9700:7500:bf00/1202001:db8::9700:7500:bfff
1932001:db8::9700:7500:c000/1202001:db8::9700:7500:c0ff
1942001:db8::9700:7500:c100/1202001:db8::9700:7500:c1ff
1952001:db8::9700:7500:c200/1202001:db8::9700:7500:c2ff
1962001:db8::9700:7500:c300/1202001:db8::9700:7500:c3ff
1972001:db8::9700:7500:c400/1202001:db8::9700:7500:c4ff
1982001:db8::9700:7500:c500/1202001:db8::9700:7500:c5ff
1992001:db8::9700:7500:c600/1202001:db8::9700:7500:c6ff
2002001:db8::9700:7500:c700/1202001:db8::9700:7500:c7ff
2012001:db8::9700:7500:c800/1202001:db8::9700:7500:c8ff
2022001:db8::9700:7500:c900/1202001:db8::9700:7500:c9ff
2032001:db8::9700:7500:ca00/1202001:db8::9700:7500:caff
2042001:db8::9700:7500:cb00/1202001:db8::9700:7500:cbff
2052001:db8::9700:7500:cc00/1202001:db8::9700:7500:ccff
2062001:db8::9700:7500:cd00/1202001:db8::9700:7500:cdff
2072001:db8::9700:7500:ce00/1202001:db8::9700:7500:ceff
2082001:db8::9700:7500:cf00/1202001:db8::9700:7500:cfff
2092001:db8::9700:7500:d000/1202001:db8::9700:7500:d0ff
2102001:db8::9700:7500:d100/1202001:db8::9700:7500:d1ff
2112001:db8::9700:7500:d200/1202001:db8::9700:7500:d2ff
2122001:db8::9700:7500:d300/1202001:db8::9700:7500:d3ff
2132001:db8::9700:7500:d400/1202001:db8::9700:7500:d4ff
2142001:db8::9700:7500:d500/1202001:db8::9700:7500:d5ff
2152001:db8::9700:7500:d600/1202001:db8::9700:7500:d6ff
2162001:db8::9700:7500:d700/1202001:db8::9700:7500:d7ff
2172001:db8::9700:7500:d800/1202001:db8::9700:7500:d8ff
2182001:db8::9700:7500:d900/1202001:db8::9700:7500:d9ff
2192001:db8::9700:7500:da00/1202001:db8::9700:7500:daff
2202001:db8::9700:7500:db00/1202001:db8::9700:7500:dbff
2212001:db8::9700:7500:dc00/1202001:db8::9700:7500:dcff
2222001:db8::9700:7500:dd00/1202001:db8::9700:7500:ddff
2232001:db8::9700:7500:de00/1202001:db8::9700:7500:deff
2242001:db8::9700:7500:df00/1202001:db8::9700:7500:dfff
2252001:db8::9700:7500:e000/1202001:db8::9700:7500:e0ff
2262001:db8::9700:7500:e100/1202001:db8::9700:7500:e1ff
2272001:db8::9700:7500:e200/1202001:db8::9700:7500:e2ff
2282001:db8::9700:7500:e300/1202001:db8::9700:7500:e3ff
2292001:db8::9700:7500:e400/1202001:db8::9700:7500:e4ff
2302001:db8::9700:7500:e500/1202001:db8::9700:7500:e5ff
2312001:db8::9700:7500:e600/1202001:db8::9700:7500:e6ff
2322001:db8::9700:7500:e700/1202001:db8::9700:7500:e7ff
2332001:db8::9700:7500:e800/1202001:db8::9700:7500:e8ff
2342001:db8::9700:7500:e900/1202001:db8::9700:7500:e9ff
2352001:db8::9700:7500:ea00/1202001:db8::9700:7500:eaff
2362001:db8::9700:7500:eb00/1202001:db8::9700:7500:ebff
2372001:db8::9700:7500:ec00/1202001:db8::9700:7500:ecff
2382001:db8::9700:7500:ed00/1202001:db8::9700:7500:edff
2392001:db8::9700:7500:ee00/1202001:db8::9700:7500:eeff
2402001:db8::9700:7500:ef00/1202001:db8::9700:7500:efff
2412001:db8::9700:7500:f000/1202001:db8::9700:7500:f0ff
2422001:db8::9700:7500:f100/1202001:db8::9700:7500:f1ff
2432001:db8::9700:7500:f200/1202001:db8::9700:7500:f2ff
2442001:db8::9700:7500:f300/1202001:db8::9700:7500:f3ff
2452001:db8::9700:7500:f400/1202001:db8::9700:7500:f4ff
2462001:db8::9700:7500:f500/1202001:db8::9700:7500:f5ff
2472001:db8::9700:7500:f600/1202001:db8::9700:7500:f6ff
2482001:db8::9700:7500:f700/1202001:db8::9700:7500:f7ff
2492001:db8::9700:7500:f800/1202001:db8::9700:7500:f8ff
2502001:db8::9700:7500:f900/1202001:db8::9700:7500:f9ff
2512001:db8::9700:7500:fa00/1202001:db8::9700:7500:faff
2522001:db8::9700:7500:fb00/1202001:db8::9700:7500:fbff
2532001:db8::9700:7500:fc00/1202001:db8::9700:7500:fcff
2542001:db8::9700:7500:fd00/1202001:db8::9700:7500:fdff
2552001:db8::9700:7500:fe00/1202001:db8::9700:7500:feff
2562001:db8::9700:7500:ff00/1202001:db8::9700:7500: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.