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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
2084::/16
First address
2084::
Last address
2084: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
2084:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
4.8.0.2.ip6.arpa
Split into smaller subnets/32
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

2084::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
12084::/322084:0:ffff:ffff:ffff:ffff:ffff:ffff
22084:1::/322084:1:ffff:ffff:ffff:ffff:ffff:ffff
32084:2::/322084:2:ffff:ffff:ffff:ffff:ffff:ffff
42084:3::/322084:3:ffff:ffff:ffff:ffff:ffff:ffff
52084:4::/322084:4:ffff:ffff:ffff:ffff:ffff:ffff
62084:5::/322084:5:ffff:ffff:ffff:ffff:ffff:ffff
72084:6::/322084:6:ffff:ffff:ffff:ffff:ffff:ffff
82084:7::/322084:7:ffff:ffff:ffff:ffff:ffff:ffff
92084:8::/322084:8:ffff:ffff:ffff:ffff:ffff:ffff
102084:9::/322084:9:ffff:ffff:ffff:ffff:ffff:ffff
112084:a::/322084:a:ffff:ffff:ffff:ffff:ffff:ffff
122084:b::/322084:b:ffff:ffff:ffff:ffff:ffff:ffff
132084:c::/322084:c:ffff:ffff:ffff:ffff:ffff:ffff
142084:d::/322084:d:ffff:ffff:ffff:ffff:ffff:ffff
152084:e::/322084:e:ffff:ffff:ffff:ffff:ffff:ffff
162084:f::/322084:f:ffff:ffff:ffff:ffff:ffff:ffff
172084:10::/322084:10:ffff:ffff:ffff:ffff:ffff:ffff
182084:11::/322084:11:ffff:ffff:ffff:ffff:ffff:ffff
192084:12::/322084:12:ffff:ffff:ffff:ffff:ffff:ffff
202084:13::/322084:13:ffff:ffff:ffff:ffff:ffff:ffff
212084:14::/322084:14:ffff:ffff:ffff:ffff:ffff:ffff
222084:15::/322084:15:ffff:ffff:ffff:ffff:ffff:ffff
232084:16::/322084:16:ffff:ffff:ffff:ffff:ffff:ffff
242084:17::/322084:17:ffff:ffff:ffff:ffff:ffff:ffff
252084:18::/322084:18:ffff:ffff:ffff:ffff:ffff:ffff
262084:19::/322084:19:ffff:ffff:ffff:ffff:ffff:ffff
272084:1a::/322084:1a:ffff:ffff:ffff:ffff:ffff:ffff
282084:1b::/322084:1b:ffff:ffff:ffff:ffff:ffff:ffff
292084:1c::/322084:1c:ffff:ffff:ffff:ffff:ffff:ffff
302084:1d::/322084:1d:ffff:ffff:ffff:ffff:ffff:ffff
312084:1e::/322084:1e:ffff:ffff:ffff:ffff:ffff:ffff
322084:1f::/322084:1f:ffff:ffff:ffff:ffff:ffff:ffff
332084:20::/322084:20:ffff:ffff:ffff:ffff:ffff:ffff
342084:21::/322084:21:ffff:ffff:ffff:ffff:ffff:ffff
352084:22::/322084:22:ffff:ffff:ffff:ffff:ffff:ffff
362084:23::/322084:23:ffff:ffff:ffff:ffff:ffff:ffff
372084:24::/322084:24:ffff:ffff:ffff:ffff:ffff:ffff
382084:25::/322084:25:ffff:ffff:ffff:ffff:ffff:ffff
392084:26::/322084:26:ffff:ffff:ffff:ffff:ffff:ffff
402084:27::/322084:27:ffff:ffff:ffff:ffff:ffff:ffff
412084:28::/322084:28:ffff:ffff:ffff:ffff:ffff:ffff
422084:29::/322084:29:ffff:ffff:ffff:ffff:ffff:ffff
432084:2a::/322084:2a:ffff:ffff:ffff:ffff:ffff:ffff
442084:2b::/322084:2b:ffff:ffff:ffff:ffff:ffff:ffff
452084:2c::/322084:2c:ffff:ffff:ffff:ffff:ffff:ffff
462084:2d::/322084:2d:ffff:ffff:ffff:ffff:ffff:ffff
472084:2e::/322084:2e:ffff:ffff:ffff:ffff:ffff:ffff
482084:2f::/322084:2f:ffff:ffff:ffff:ffff:ffff:ffff
492084:30::/322084:30:ffff:ffff:ffff:ffff:ffff:ffff
502084:31::/322084:31:ffff:ffff:ffff:ffff:ffff:ffff
512084:32::/322084:32:ffff:ffff:ffff:ffff:ffff:ffff
522084:33::/322084:33:ffff:ffff:ffff:ffff:ffff:ffff
532084:34::/322084:34:ffff:ffff:ffff:ffff:ffff:ffff
542084:35::/322084:35:ffff:ffff:ffff:ffff:ffff:ffff
552084:36::/322084:36:ffff:ffff:ffff:ffff:ffff:ffff
562084:37::/322084:37:ffff:ffff:ffff:ffff:ffff:ffff
572084:38::/322084:38:ffff:ffff:ffff:ffff:ffff:ffff
582084:39::/322084:39:ffff:ffff:ffff:ffff:ffff:ffff
592084:3a::/322084:3a:ffff:ffff:ffff:ffff:ffff:ffff
602084:3b::/322084:3b:ffff:ffff:ffff:ffff:ffff:ffff
612084:3c::/322084:3c:ffff:ffff:ffff:ffff:ffff:ffff
622084:3d::/322084:3d:ffff:ffff:ffff:ffff:ffff:ffff
632084:3e::/322084:3e:ffff:ffff:ffff:ffff:ffff:ffff
642084:3f::/322084:3f:ffff:ffff:ffff:ffff:ffff:ffff
652084:40::/322084:40:ffff:ffff:ffff:ffff:ffff:ffff
662084:41::/322084:41:ffff:ffff:ffff:ffff:ffff:ffff
672084:42::/322084:42:ffff:ffff:ffff:ffff:ffff:ffff
682084:43::/322084:43:ffff:ffff:ffff:ffff:ffff:ffff
692084:44::/322084:44:ffff:ffff:ffff:ffff:ffff:ffff
702084:45::/322084:45:ffff:ffff:ffff:ffff:ffff:ffff
712084:46::/322084:46:ffff:ffff:ffff:ffff:ffff:ffff
722084:47::/322084:47:ffff:ffff:ffff:ffff:ffff:ffff
732084:48::/322084:48:ffff:ffff:ffff:ffff:ffff:ffff
742084:49::/322084:49:ffff:ffff:ffff:ffff:ffff:ffff
752084:4a::/322084:4a:ffff:ffff:ffff:ffff:ffff:ffff
762084:4b::/322084:4b:ffff:ffff:ffff:ffff:ffff:ffff
772084:4c::/322084:4c:ffff:ffff:ffff:ffff:ffff:ffff
782084:4d::/322084:4d:ffff:ffff:ffff:ffff:ffff:ffff
792084:4e::/322084:4e:ffff:ffff:ffff:ffff:ffff:ffff
802084:4f::/322084:4f:ffff:ffff:ffff:ffff:ffff:ffff
812084:50::/322084:50:ffff:ffff:ffff:ffff:ffff:ffff
822084:51::/322084:51:ffff:ffff:ffff:ffff:ffff:ffff
832084:52::/322084:52:ffff:ffff:ffff:ffff:ffff:ffff
842084:53::/322084:53:ffff:ffff:ffff:ffff:ffff:ffff
852084:54::/322084:54:ffff:ffff:ffff:ffff:ffff:ffff
862084:55::/322084:55:ffff:ffff:ffff:ffff:ffff:ffff
872084:56::/322084:56:ffff:ffff:ffff:ffff:ffff:ffff
882084:57::/322084:57:ffff:ffff:ffff:ffff:ffff:ffff
892084:58::/322084:58:ffff:ffff:ffff:ffff:ffff:ffff
902084:59::/322084:59:ffff:ffff:ffff:ffff:ffff:ffff
912084:5a::/322084:5a:ffff:ffff:ffff:ffff:ffff:ffff
922084:5b::/322084:5b:ffff:ffff:ffff:ffff:ffff:ffff
932084:5c::/322084:5c:ffff:ffff:ffff:ffff:ffff:ffff
942084:5d::/322084:5d:ffff:ffff:ffff:ffff:ffff:ffff
952084:5e::/322084:5e:ffff:ffff:ffff:ffff:ffff:ffff
962084:5f::/322084:5f:ffff:ffff:ffff:ffff:ffff:ffff
972084:60::/322084:60:ffff:ffff:ffff:ffff:ffff:ffff
982084:61::/322084:61:ffff:ffff:ffff:ffff:ffff:ffff
992084:62::/322084:62:ffff:ffff:ffff:ffff:ffff:ffff
1002084:63::/322084:63:ffff:ffff:ffff:ffff:ffff:ffff
1012084:64::/322084:64:ffff:ffff:ffff:ffff:ffff:ffff
1022084:65::/322084:65:ffff:ffff:ffff:ffff:ffff:ffff
1032084:66::/322084:66:ffff:ffff:ffff:ffff:ffff:ffff
1042084:67::/322084:67:ffff:ffff:ffff:ffff:ffff:ffff
1052084:68::/322084:68:ffff:ffff:ffff:ffff:ffff:ffff
1062084:69::/322084:69:ffff:ffff:ffff:ffff:ffff:ffff
1072084:6a::/322084:6a:ffff:ffff:ffff:ffff:ffff:ffff
1082084:6b::/322084:6b:ffff:ffff:ffff:ffff:ffff:ffff
1092084:6c::/322084:6c:ffff:ffff:ffff:ffff:ffff:ffff
1102084:6d::/322084:6d:ffff:ffff:ffff:ffff:ffff:ffff
1112084:6e::/322084:6e:ffff:ffff:ffff:ffff:ffff:ffff
1122084:6f::/322084:6f:ffff:ffff:ffff:ffff:ffff:ffff
1132084:70::/322084:70:ffff:ffff:ffff:ffff:ffff:ffff
1142084:71::/322084:71:ffff:ffff:ffff:ffff:ffff:ffff
1152084:72::/322084:72:ffff:ffff:ffff:ffff:ffff:ffff
1162084:73::/322084:73:ffff:ffff:ffff:ffff:ffff:ffff
1172084:74::/322084:74:ffff:ffff:ffff:ffff:ffff:ffff
1182084:75::/322084:75:ffff:ffff:ffff:ffff:ffff:ffff
1192084:76::/322084:76:ffff:ffff:ffff:ffff:ffff:ffff
1202084:77::/322084:77:ffff:ffff:ffff:ffff:ffff:ffff
1212084:78::/322084:78:ffff:ffff:ffff:ffff:ffff:ffff
1222084:79::/322084:79:ffff:ffff:ffff:ffff:ffff:ffff
1232084:7a::/322084:7a:ffff:ffff:ffff:ffff:ffff:ffff
1242084:7b::/322084:7b:ffff:ffff:ffff:ffff:ffff:ffff
1252084:7c::/322084:7c:ffff:ffff:ffff:ffff:ffff:ffff
1262084:7d::/322084:7d:ffff:ffff:ffff:ffff:ffff:ffff
1272084:7e::/322084:7e:ffff:ffff:ffff:ffff:ffff:ffff
1282084:7f::/322084:7f:ffff:ffff:ffff:ffff:ffff:ffff
1292084:80::/322084:80:ffff:ffff:ffff:ffff:ffff:ffff
1302084:81::/322084:81:ffff:ffff:ffff:ffff:ffff:ffff
1312084:82::/322084:82:ffff:ffff:ffff:ffff:ffff:ffff
1322084:83::/322084:83:ffff:ffff:ffff:ffff:ffff:ffff
1332084:84::/322084:84:ffff:ffff:ffff:ffff:ffff:ffff
1342084:85::/322084:85:ffff:ffff:ffff:ffff:ffff:ffff
1352084:86::/322084:86:ffff:ffff:ffff:ffff:ffff:ffff
1362084:87::/322084:87:ffff:ffff:ffff:ffff:ffff:ffff
1372084:88::/322084:88:ffff:ffff:ffff:ffff:ffff:ffff
1382084:89::/322084:89:ffff:ffff:ffff:ffff:ffff:ffff
1392084:8a::/322084:8a:ffff:ffff:ffff:ffff:ffff:ffff
1402084:8b::/322084:8b:ffff:ffff:ffff:ffff:ffff:ffff
1412084:8c::/322084:8c:ffff:ffff:ffff:ffff:ffff:ffff
1422084:8d::/322084:8d:ffff:ffff:ffff:ffff:ffff:ffff
1432084:8e::/322084:8e:ffff:ffff:ffff:ffff:ffff:ffff
1442084:8f::/322084:8f:ffff:ffff:ffff:ffff:ffff:ffff
1452084:90::/322084:90:ffff:ffff:ffff:ffff:ffff:ffff
1462084:91::/322084:91:ffff:ffff:ffff:ffff:ffff:ffff
1472084:92::/322084:92:ffff:ffff:ffff:ffff:ffff:ffff
1482084:93::/322084:93:ffff:ffff:ffff:ffff:ffff:ffff
1492084:94::/322084:94:ffff:ffff:ffff:ffff:ffff:ffff
1502084:95::/322084:95:ffff:ffff:ffff:ffff:ffff:ffff
1512084:96::/322084:96:ffff:ffff:ffff:ffff:ffff:ffff
1522084:97::/322084:97:ffff:ffff:ffff:ffff:ffff:ffff
1532084:98::/322084:98:ffff:ffff:ffff:ffff:ffff:ffff
1542084:99::/322084:99:ffff:ffff:ffff:ffff:ffff:ffff
1552084:9a::/322084:9a:ffff:ffff:ffff:ffff:ffff:ffff
1562084:9b::/322084:9b:ffff:ffff:ffff:ffff:ffff:ffff
1572084:9c::/322084:9c:ffff:ffff:ffff:ffff:ffff:ffff
1582084:9d::/322084:9d:ffff:ffff:ffff:ffff:ffff:ffff
1592084:9e::/322084:9e:ffff:ffff:ffff:ffff:ffff:ffff
1602084:9f::/322084:9f:ffff:ffff:ffff:ffff:ffff:ffff
1612084:a0::/322084:a0:ffff:ffff:ffff:ffff:ffff:ffff
1622084:a1::/322084:a1:ffff:ffff:ffff:ffff:ffff:ffff
1632084:a2::/322084:a2:ffff:ffff:ffff:ffff:ffff:ffff
1642084:a3::/322084:a3:ffff:ffff:ffff:ffff:ffff:ffff
1652084:a4::/322084:a4:ffff:ffff:ffff:ffff:ffff:ffff
1662084:a5::/322084:a5:ffff:ffff:ffff:ffff:ffff:ffff
1672084:a6::/322084:a6:ffff:ffff:ffff:ffff:ffff:ffff
1682084:a7::/322084:a7:ffff:ffff:ffff:ffff:ffff:ffff
1692084:a8::/322084:a8:ffff:ffff:ffff:ffff:ffff:ffff
1702084:a9::/322084:a9:ffff:ffff:ffff:ffff:ffff:ffff
1712084:aa::/322084:aa:ffff:ffff:ffff:ffff:ffff:ffff
1722084:ab::/322084:ab:ffff:ffff:ffff:ffff:ffff:ffff
1732084:ac::/322084:ac:ffff:ffff:ffff:ffff:ffff:ffff
1742084:ad::/322084:ad:ffff:ffff:ffff:ffff:ffff:ffff
1752084:ae::/322084:ae:ffff:ffff:ffff:ffff:ffff:ffff
1762084:af::/322084:af:ffff:ffff:ffff:ffff:ffff:ffff
1772084:b0::/322084:b0:ffff:ffff:ffff:ffff:ffff:ffff
1782084:b1::/322084:b1:ffff:ffff:ffff:ffff:ffff:ffff
1792084:b2::/322084:b2:ffff:ffff:ffff:ffff:ffff:ffff
1802084:b3::/322084:b3:ffff:ffff:ffff:ffff:ffff:ffff
1812084:b4::/322084:b4:ffff:ffff:ffff:ffff:ffff:ffff
1822084:b5::/322084:b5:ffff:ffff:ffff:ffff:ffff:ffff
1832084:b6::/322084:b6:ffff:ffff:ffff:ffff:ffff:ffff
1842084:b7::/322084:b7:ffff:ffff:ffff:ffff:ffff:ffff
1852084:b8::/322084:b8:ffff:ffff:ffff:ffff:ffff:ffff
1862084:b9::/322084:b9:ffff:ffff:ffff:ffff:ffff:ffff
1872084:ba::/322084:ba:ffff:ffff:ffff:ffff:ffff:ffff
1882084:bb::/322084:bb:ffff:ffff:ffff:ffff:ffff:ffff
1892084:bc::/322084:bc:ffff:ffff:ffff:ffff:ffff:ffff
1902084:bd::/322084:bd:ffff:ffff:ffff:ffff:ffff:ffff
1912084:be::/322084:be:ffff:ffff:ffff:ffff:ffff:ffff
1922084:bf::/322084:bf:ffff:ffff:ffff:ffff:ffff:ffff
1932084:c0::/322084:c0:ffff:ffff:ffff:ffff:ffff:ffff
1942084:c1::/322084:c1:ffff:ffff:ffff:ffff:ffff:ffff
1952084:c2::/322084:c2:ffff:ffff:ffff:ffff:ffff:ffff
1962084:c3::/322084:c3:ffff:ffff:ffff:ffff:ffff:ffff
1972084:c4::/322084:c4:ffff:ffff:ffff:ffff:ffff:ffff
1982084:c5::/322084:c5:ffff:ffff:ffff:ffff:ffff:ffff
1992084:c6::/322084:c6:ffff:ffff:ffff:ffff:ffff:ffff
2002084:c7::/322084:c7:ffff:ffff:ffff:ffff:ffff:ffff
2012084:c8::/322084:c8:ffff:ffff:ffff:ffff:ffff:ffff
2022084:c9::/322084:c9:ffff:ffff:ffff:ffff:ffff:ffff
2032084:ca::/322084:ca:ffff:ffff:ffff:ffff:ffff:ffff
2042084:cb::/322084:cb:ffff:ffff:ffff:ffff:ffff:ffff
2052084:cc::/322084:cc:ffff:ffff:ffff:ffff:ffff:ffff
2062084:cd::/322084:cd:ffff:ffff:ffff:ffff:ffff:ffff
2072084:ce::/322084:ce:ffff:ffff:ffff:ffff:ffff:ffff
2082084:cf::/322084:cf:ffff:ffff:ffff:ffff:ffff:ffff
2092084:d0::/322084:d0:ffff:ffff:ffff:ffff:ffff:ffff
2102084:d1::/322084:d1:ffff:ffff:ffff:ffff:ffff:ffff
2112084:d2::/322084:d2:ffff:ffff:ffff:ffff:ffff:ffff
2122084:d3::/322084:d3:ffff:ffff:ffff:ffff:ffff:ffff
2132084:d4::/322084:d4:ffff:ffff:ffff:ffff:ffff:ffff
2142084:d5::/322084:d5:ffff:ffff:ffff:ffff:ffff:ffff
2152084:d6::/322084:d6:ffff:ffff:ffff:ffff:ffff:ffff
2162084:d7::/322084:d7:ffff:ffff:ffff:ffff:ffff:ffff
2172084:d8::/322084:d8:ffff:ffff:ffff:ffff:ffff:ffff
2182084:d9::/322084:d9:ffff:ffff:ffff:ffff:ffff:ffff
2192084:da::/322084:da:ffff:ffff:ffff:ffff:ffff:ffff
2202084:db::/322084:db:ffff:ffff:ffff:ffff:ffff:ffff
2212084:dc::/322084:dc:ffff:ffff:ffff:ffff:ffff:ffff
2222084:dd::/322084:dd:ffff:ffff:ffff:ffff:ffff:ffff
2232084:de::/322084:de:ffff:ffff:ffff:ffff:ffff:ffff
2242084:df::/322084:df:ffff:ffff:ffff:ffff:ffff:ffff
2252084:e0::/322084:e0:ffff:ffff:ffff:ffff:ffff:ffff
2262084:e1::/322084:e1:ffff:ffff:ffff:ffff:ffff:ffff
2272084:e2::/322084:e2:ffff:ffff:ffff:ffff:ffff:ffff
2282084:e3::/322084:e3:ffff:ffff:ffff:ffff:ffff:ffff
2292084:e4::/322084:e4:ffff:ffff:ffff:ffff:ffff:ffff
2302084:e5::/322084:e5:ffff:ffff:ffff:ffff:ffff:ffff
2312084:e6::/322084:e6:ffff:ffff:ffff:ffff:ffff:ffff
2322084:e7::/322084:e7:ffff:ffff:ffff:ffff:ffff:ffff
2332084:e8::/322084:e8:ffff:ffff:ffff:ffff:ffff:ffff
2342084:e9::/322084:e9:ffff:ffff:ffff:ffff:ffff:ffff
2352084:ea::/322084:ea:ffff:ffff:ffff:ffff:ffff:ffff
2362084:eb::/322084:eb:ffff:ffff:ffff:ffff:ffff:ffff
2372084:ec::/322084:ec:ffff:ffff:ffff:ffff:ffff:ffff
2382084:ed::/322084:ed:ffff:ffff:ffff:ffff:ffff:ffff
2392084:ee::/322084:ee:ffff:ffff:ffff:ffff:ffff:ffff
2402084:ef::/322084:ef:ffff:ffff:ffff:ffff:ffff:ffff
2412084:f0::/322084:f0:ffff:ffff:ffff:ffff:ffff:ffff
2422084:f1::/322084:f1:ffff:ffff:ffff:ffff:ffff:ffff
2432084:f2::/322084:f2:ffff:ffff:ffff:ffff:ffff:ffff
2442084:f3::/322084:f3:ffff:ffff:ffff:ffff:ffff:ffff
2452084:f4::/322084:f4:ffff:ffff:ffff:ffff:ffff:ffff
2462084:f5::/322084:f5:ffff:ffff:ffff:ffff:ffff:ffff
2472084:f6::/322084:f6:ffff:ffff:ffff:ffff:ffff:ffff
2482084:f7::/322084:f7:ffff:ffff:ffff:ffff:ffff:ffff
2492084:f8::/322084:f8:ffff:ffff:ffff:ffff:ffff:ffff
2502084:f9::/322084:f9:ffff:ffff:ffff:ffff:ffff:ffff
2512084:fa::/322084:fa:ffff:ffff:ffff:ffff:ffff:ffff
2522084:fb::/322084:fb:ffff:ffff:ffff:ffff:ffff:ffff
2532084:fc::/322084:fc:ffff:ffff:ffff:ffff:ffff:ffff
2542084:fd::/322084:fd:ffff:ffff:ffff:ffff:ffff:ffff
2552084:fe::/322084:fe:ffff:ffff:ffff:ffff:ffff:ffff
2562084:ff::/322084:ff: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.