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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
2ca6::/16
First address
2ca6::
Last address
2ca6: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
2ca6:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
6.a.c.2.ip6.arpa
Split into smaller subnets/32
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

2ca6::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
12ca6::/322ca6:0:ffff:ffff:ffff:ffff:ffff:ffff
22ca6:1::/322ca6:1:ffff:ffff:ffff:ffff:ffff:ffff
32ca6:2::/322ca6:2:ffff:ffff:ffff:ffff:ffff:ffff
42ca6:3::/322ca6:3:ffff:ffff:ffff:ffff:ffff:ffff
52ca6:4::/322ca6:4:ffff:ffff:ffff:ffff:ffff:ffff
62ca6:5::/322ca6:5:ffff:ffff:ffff:ffff:ffff:ffff
72ca6:6::/322ca6:6:ffff:ffff:ffff:ffff:ffff:ffff
82ca6:7::/322ca6:7:ffff:ffff:ffff:ffff:ffff:ffff
92ca6:8::/322ca6:8:ffff:ffff:ffff:ffff:ffff:ffff
102ca6:9::/322ca6:9:ffff:ffff:ffff:ffff:ffff:ffff
112ca6:a::/322ca6:a:ffff:ffff:ffff:ffff:ffff:ffff
122ca6:b::/322ca6:b:ffff:ffff:ffff:ffff:ffff:ffff
132ca6:c::/322ca6:c:ffff:ffff:ffff:ffff:ffff:ffff
142ca6:d::/322ca6:d:ffff:ffff:ffff:ffff:ffff:ffff
152ca6:e::/322ca6:e:ffff:ffff:ffff:ffff:ffff:ffff
162ca6:f::/322ca6:f:ffff:ffff:ffff:ffff:ffff:ffff
172ca6:10::/322ca6:10:ffff:ffff:ffff:ffff:ffff:ffff
182ca6:11::/322ca6:11:ffff:ffff:ffff:ffff:ffff:ffff
192ca6:12::/322ca6:12:ffff:ffff:ffff:ffff:ffff:ffff
202ca6:13::/322ca6:13:ffff:ffff:ffff:ffff:ffff:ffff
212ca6:14::/322ca6:14:ffff:ffff:ffff:ffff:ffff:ffff
222ca6:15::/322ca6:15:ffff:ffff:ffff:ffff:ffff:ffff
232ca6:16::/322ca6:16:ffff:ffff:ffff:ffff:ffff:ffff
242ca6:17::/322ca6:17:ffff:ffff:ffff:ffff:ffff:ffff
252ca6:18::/322ca6:18:ffff:ffff:ffff:ffff:ffff:ffff
262ca6:19::/322ca6:19:ffff:ffff:ffff:ffff:ffff:ffff
272ca6:1a::/322ca6:1a:ffff:ffff:ffff:ffff:ffff:ffff
282ca6:1b::/322ca6:1b:ffff:ffff:ffff:ffff:ffff:ffff
292ca6:1c::/322ca6:1c:ffff:ffff:ffff:ffff:ffff:ffff
302ca6:1d::/322ca6:1d:ffff:ffff:ffff:ffff:ffff:ffff
312ca6:1e::/322ca6:1e:ffff:ffff:ffff:ffff:ffff:ffff
322ca6:1f::/322ca6:1f:ffff:ffff:ffff:ffff:ffff:ffff
332ca6:20::/322ca6:20:ffff:ffff:ffff:ffff:ffff:ffff
342ca6:21::/322ca6:21:ffff:ffff:ffff:ffff:ffff:ffff
352ca6:22::/322ca6:22:ffff:ffff:ffff:ffff:ffff:ffff
362ca6:23::/322ca6:23:ffff:ffff:ffff:ffff:ffff:ffff
372ca6:24::/322ca6:24:ffff:ffff:ffff:ffff:ffff:ffff
382ca6:25::/322ca6:25:ffff:ffff:ffff:ffff:ffff:ffff
392ca6:26::/322ca6:26:ffff:ffff:ffff:ffff:ffff:ffff
402ca6:27::/322ca6:27:ffff:ffff:ffff:ffff:ffff:ffff
412ca6:28::/322ca6:28:ffff:ffff:ffff:ffff:ffff:ffff
422ca6:29::/322ca6:29:ffff:ffff:ffff:ffff:ffff:ffff
432ca6:2a::/322ca6:2a:ffff:ffff:ffff:ffff:ffff:ffff
442ca6:2b::/322ca6:2b:ffff:ffff:ffff:ffff:ffff:ffff
452ca6:2c::/322ca6:2c:ffff:ffff:ffff:ffff:ffff:ffff
462ca6:2d::/322ca6:2d:ffff:ffff:ffff:ffff:ffff:ffff
472ca6:2e::/322ca6:2e:ffff:ffff:ffff:ffff:ffff:ffff
482ca6:2f::/322ca6:2f:ffff:ffff:ffff:ffff:ffff:ffff
492ca6:30::/322ca6:30:ffff:ffff:ffff:ffff:ffff:ffff
502ca6:31::/322ca6:31:ffff:ffff:ffff:ffff:ffff:ffff
512ca6:32::/322ca6:32:ffff:ffff:ffff:ffff:ffff:ffff
522ca6:33::/322ca6:33:ffff:ffff:ffff:ffff:ffff:ffff
532ca6:34::/322ca6:34:ffff:ffff:ffff:ffff:ffff:ffff
542ca6:35::/322ca6:35:ffff:ffff:ffff:ffff:ffff:ffff
552ca6:36::/322ca6:36:ffff:ffff:ffff:ffff:ffff:ffff
562ca6:37::/322ca6:37:ffff:ffff:ffff:ffff:ffff:ffff
572ca6:38::/322ca6:38:ffff:ffff:ffff:ffff:ffff:ffff
582ca6:39::/322ca6:39:ffff:ffff:ffff:ffff:ffff:ffff
592ca6:3a::/322ca6:3a:ffff:ffff:ffff:ffff:ffff:ffff
602ca6:3b::/322ca6:3b:ffff:ffff:ffff:ffff:ffff:ffff
612ca6:3c::/322ca6:3c:ffff:ffff:ffff:ffff:ffff:ffff
622ca6:3d::/322ca6:3d:ffff:ffff:ffff:ffff:ffff:ffff
632ca6:3e::/322ca6:3e:ffff:ffff:ffff:ffff:ffff:ffff
642ca6:3f::/322ca6:3f:ffff:ffff:ffff:ffff:ffff:ffff
652ca6:40::/322ca6:40:ffff:ffff:ffff:ffff:ffff:ffff
662ca6:41::/322ca6:41:ffff:ffff:ffff:ffff:ffff:ffff
672ca6:42::/322ca6:42:ffff:ffff:ffff:ffff:ffff:ffff
682ca6:43::/322ca6:43:ffff:ffff:ffff:ffff:ffff:ffff
692ca6:44::/322ca6:44:ffff:ffff:ffff:ffff:ffff:ffff
702ca6:45::/322ca6:45:ffff:ffff:ffff:ffff:ffff:ffff
712ca6:46::/322ca6:46:ffff:ffff:ffff:ffff:ffff:ffff
722ca6:47::/322ca6:47:ffff:ffff:ffff:ffff:ffff:ffff
732ca6:48::/322ca6:48:ffff:ffff:ffff:ffff:ffff:ffff
742ca6:49::/322ca6:49:ffff:ffff:ffff:ffff:ffff:ffff
752ca6:4a::/322ca6:4a:ffff:ffff:ffff:ffff:ffff:ffff
762ca6:4b::/322ca6:4b:ffff:ffff:ffff:ffff:ffff:ffff
772ca6:4c::/322ca6:4c:ffff:ffff:ffff:ffff:ffff:ffff
782ca6:4d::/322ca6:4d:ffff:ffff:ffff:ffff:ffff:ffff
792ca6:4e::/322ca6:4e:ffff:ffff:ffff:ffff:ffff:ffff
802ca6:4f::/322ca6:4f:ffff:ffff:ffff:ffff:ffff:ffff
812ca6:50::/322ca6:50:ffff:ffff:ffff:ffff:ffff:ffff
822ca6:51::/322ca6:51:ffff:ffff:ffff:ffff:ffff:ffff
832ca6:52::/322ca6:52:ffff:ffff:ffff:ffff:ffff:ffff
842ca6:53::/322ca6:53:ffff:ffff:ffff:ffff:ffff:ffff
852ca6:54::/322ca6:54:ffff:ffff:ffff:ffff:ffff:ffff
862ca6:55::/322ca6:55:ffff:ffff:ffff:ffff:ffff:ffff
872ca6:56::/322ca6:56:ffff:ffff:ffff:ffff:ffff:ffff
882ca6:57::/322ca6:57:ffff:ffff:ffff:ffff:ffff:ffff
892ca6:58::/322ca6:58:ffff:ffff:ffff:ffff:ffff:ffff
902ca6:59::/322ca6:59:ffff:ffff:ffff:ffff:ffff:ffff
912ca6:5a::/322ca6:5a:ffff:ffff:ffff:ffff:ffff:ffff
922ca6:5b::/322ca6:5b:ffff:ffff:ffff:ffff:ffff:ffff
932ca6:5c::/322ca6:5c:ffff:ffff:ffff:ffff:ffff:ffff
942ca6:5d::/322ca6:5d:ffff:ffff:ffff:ffff:ffff:ffff
952ca6:5e::/322ca6:5e:ffff:ffff:ffff:ffff:ffff:ffff
962ca6:5f::/322ca6:5f:ffff:ffff:ffff:ffff:ffff:ffff
972ca6:60::/322ca6:60:ffff:ffff:ffff:ffff:ffff:ffff
982ca6:61::/322ca6:61:ffff:ffff:ffff:ffff:ffff:ffff
992ca6:62::/322ca6:62:ffff:ffff:ffff:ffff:ffff:ffff
1002ca6:63::/322ca6:63:ffff:ffff:ffff:ffff:ffff:ffff
1012ca6:64::/322ca6:64:ffff:ffff:ffff:ffff:ffff:ffff
1022ca6:65::/322ca6:65:ffff:ffff:ffff:ffff:ffff:ffff
1032ca6:66::/322ca6:66:ffff:ffff:ffff:ffff:ffff:ffff
1042ca6:67::/322ca6:67:ffff:ffff:ffff:ffff:ffff:ffff
1052ca6:68::/322ca6:68:ffff:ffff:ffff:ffff:ffff:ffff
1062ca6:69::/322ca6:69:ffff:ffff:ffff:ffff:ffff:ffff
1072ca6:6a::/322ca6:6a:ffff:ffff:ffff:ffff:ffff:ffff
1082ca6:6b::/322ca6:6b:ffff:ffff:ffff:ffff:ffff:ffff
1092ca6:6c::/322ca6:6c:ffff:ffff:ffff:ffff:ffff:ffff
1102ca6:6d::/322ca6:6d:ffff:ffff:ffff:ffff:ffff:ffff
1112ca6:6e::/322ca6:6e:ffff:ffff:ffff:ffff:ffff:ffff
1122ca6:6f::/322ca6:6f:ffff:ffff:ffff:ffff:ffff:ffff
1132ca6:70::/322ca6:70:ffff:ffff:ffff:ffff:ffff:ffff
1142ca6:71::/322ca6:71:ffff:ffff:ffff:ffff:ffff:ffff
1152ca6:72::/322ca6:72:ffff:ffff:ffff:ffff:ffff:ffff
1162ca6:73::/322ca6:73:ffff:ffff:ffff:ffff:ffff:ffff
1172ca6:74::/322ca6:74:ffff:ffff:ffff:ffff:ffff:ffff
1182ca6:75::/322ca6:75:ffff:ffff:ffff:ffff:ffff:ffff
1192ca6:76::/322ca6:76:ffff:ffff:ffff:ffff:ffff:ffff
1202ca6:77::/322ca6:77:ffff:ffff:ffff:ffff:ffff:ffff
1212ca6:78::/322ca6:78:ffff:ffff:ffff:ffff:ffff:ffff
1222ca6:79::/322ca6:79:ffff:ffff:ffff:ffff:ffff:ffff
1232ca6:7a::/322ca6:7a:ffff:ffff:ffff:ffff:ffff:ffff
1242ca6:7b::/322ca6:7b:ffff:ffff:ffff:ffff:ffff:ffff
1252ca6:7c::/322ca6:7c:ffff:ffff:ffff:ffff:ffff:ffff
1262ca6:7d::/322ca6:7d:ffff:ffff:ffff:ffff:ffff:ffff
1272ca6:7e::/322ca6:7e:ffff:ffff:ffff:ffff:ffff:ffff
1282ca6:7f::/322ca6:7f:ffff:ffff:ffff:ffff:ffff:ffff
1292ca6:80::/322ca6:80:ffff:ffff:ffff:ffff:ffff:ffff
1302ca6:81::/322ca6:81:ffff:ffff:ffff:ffff:ffff:ffff
1312ca6:82::/322ca6:82:ffff:ffff:ffff:ffff:ffff:ffff
1322ca6:83::/322ca6:83:ffff:ffff:ffff:ffff:ffff:ffff
1332ca6:84::/322ca6:84:ffff:ffff:ffff:ffff:ffff:ffff
1342ca6:85::/322ca6:85:ffff:ffff:ffff:ffff:ffff:ffff
1352ca6:86::/322ca6:86:ffff:ffff:ffff:ffff:ffff:ffff
1362ca6:87::/322ca6:87:ffff:ffff:ffff:ffff:ffff:ffff
1372ca6:88::/322ca6:88:ffff:ffff:ffff:ffff:ffff:ffff
1382ca6:89::/322ca6:89:ffff:ffff:ffff:ffff:ffff:ffff
1392ca6:8a::/322ca6:8a:ffff:ffff:ffff:ffff:ffff:ffff
1402ca6:8b::/322ca6:8b:ffff:ffff:ffff:ffff:ffff:ffff
1412ca6:8c::/322ca6:8c:ffff:ffff:ffff:ffff:ffff:ffff
1422ca6:8d::/322ca6:8d:ffff:ffff:ffff:ffff:ffff:ffff
1432ca6:8e::/322ca6:8e:ffff:ffff:ffff:ffff:ffff:ffff
1442ca6:8f::/322ca6:8f:ffff:ffff:ffff:ffff:ffff:ffff
1452ca6:90::/322ca6:90:ffff:ffff:ffff:ffff:ffff:ffff
1462ca6:91::/322ca6:91:ffff:ffff:ffff:ffff:ffff:ffff
1472ca6:92::/322ca6:92:ffff:ffff:ffff:ffff:ffff:ffff
1482ca6:93::/322ca6:93:ffff:ffff:ffff:ffff:ffff:ffff
1492ca6:94::/322ca6:94:ffff:ffff:ffff:ffff:ffff:ffff
1502ca6:95::/322ca6:95:ffff:ffff:ffff:ffff:ffff:ffff
1512ca6:96::/322ca6:96:ffff:ffff:ffff:ffff:ffff:ffff
1522ca6:97::/322ca6:97:ffff:ffff:ffff:ffff:ffff:ffff
1532ca6:98::/322ca6:98:ffff:ffff:ffff:ffff:ffff:ffff
1542ca6:99::/322ca6:99:ffff:ffff:ffff:ffff:ffff:ffff
1552ca6:9a::/322ca6:9a:ffff:ffff:ffff:ffff:ffff:ffff
1562ca6:9b::/322ca6:9b:ffff:ffff:ffff:ffff:ffff:ffff
1572ca6:9c::/322ca6:9c:ffff:ffff:ffff:ffff:ffff:ffff
1582ca6:9d::/322ca6:9d:ffff:ffff:ffff:ffff:ffff:ffff
1592ca6:9e::/322ca6:9e:ffff:ffff:ffff:ffff:ffff:ffff
1602ca6:9f::/322ca6:9f:ffff:ffff:ffff:ffff:ffff:ffff
1612ca6:a0::/322ca6:a0:ffff:ffff:ffff:ffff:ffff:ffff
1622ca6:a1::/322ca6:a1:ffff:ffff:ffff:ffff:ffff:ffff
1632ca6:a2::/322ca6:a2:ffff:ffff:ffff:ffff:ffff:ffff
1642ca6:a3::/322ca6:a3:ffff:ffff:ffff:ffff:ffff:ffff
1652ca6:a4::/322ca6:a4:ffff:ffff:ffff:ffff:ffff:ffff
1662ca6:a5::/322ca6:a5:ffff:ffff:ffff:ffff:ffff:ffff
1672ca6:a6::/322ca6:a6:ffff:ffff:ffff:ffff:ffff:ffff
1682ca6:a7::/322ca6:a7:ffff:ffff:ffff:ffff:ffff:ffff
1692ca6:a8::/322ca6:a8:ffff:ffff:ffff:ffff:ffff:ffff
1702ca6:a9::/322ca6:a9:ffff:ffff:ffff:ffff:ffff:ffff
1712ca6:aa::/322ca6:aa:ffff:ffff:ffff:ffff:ffff:ffff
1722ca6:ab::/322ca6:ab:ffff:ffff:ffff:ffff:ffff:ffff
1732ca6:ac::/322ca6:ac:ffff:ffff:ffff:ffff:ffff:ffff
1742ca6:ad::/322ca6:ad:ffff:ffff:ffff:ffff:ffff:ffff
1752ca6:ae::/322ca6:ae:ffff:ffff:ffff:ffff:ffff:ffff
1762ca6:af::/322ca6:af:ffff:ffff:ffff:ffff:ffff:ffff
1772ca6:b0::/322ca6:b0:ffff:ffff:ffff:ffff:ffff:ffff
1782ca6:b1::/322ca6:b1:ffff:ffff:ffff:ffff:ffff:ffff
1792ca6:b2::/322ca6:b2:ffff:ffff:ffff:ffff:ffff:ffff
1802ca6:b3::/322ca6:b3:ffff:ffff:ffff:ffff:ffff:ffff
1812ca6:b4::/322ca6:b4:ffff:ffff:ffff:ffff:ffff:ffff
1822ca6:b5::/322ca6:b5:ffff:ffff:ffff:ffff:ffff:ffff
1832ca6:b6::/322ca6:b6:ffff:ffff:ffff:ffff:ffff:ffff
1842ca6:b7::/322ca6:b7:ffff:ffff:ffff:ffff:ffff:ffff
1852ca6:b8::/322ca6:b8:ffff:ffff:ffff:ffff:ffff:ffff
1862ca6:b9::/322ca6:b9:ffff:ffff:ffff:ffff:ffff:ffff
1872ca6:ba::/322ca6:ba:ffff:ffff:ffff:ffff:ffff:ffff
1882ca6:bb::/322ca6:bb:ffff:ffff:ffff:ffff:ffff:ffff
1892ca6:bc::/322ca6:bc:ffff:ffff:ffff:ffff:ffff:ffff
1902ca6:bd::/322ca6:bd:ffff:ffff:ffff:ffff:ffff:ffff
1912ca6:be::/322ca6:be:ffff:ffff:ffff:ffff:ffff:ffff
1922ca6:bf::/322ca6:bf:ffff:ffff:ffff:ffff:ffff:ffff
1932ca6:c0::/322ca6:c0:ffff:ffff:ffff:ffff:ffff:ffff
1942ca6:c1::/322ca6:c1:ffff:ffff:ffff:ffff:ffff:ffff
1952ca6:c2::/322ca6:c2:ffff:ffff:ffff:ffff:ffff:ffff
1962ca6:c3::/322ca6:c3:ffff:ffff:ffff:ffff:ffff:ffff
1972ca6:c4::/322ca6:c4:ffff:ffff:ffff:ffff:ffff:ffff
1982ca6:c5::/322ca6:c5:ffff:ffff:ffff:ffff:ffff:ffff
1992ca6:c6::/322ca6:c6:ffff:ffff:ffff:ffff:ffff:ffff
2002ca6:c7::/322ca6:c7:ffff:ffff:ffff:ffff:ffff:ffff
2012ca6:c8::/322ca6:c8:ffff:ffff:ffff:ffff:ffff:ffff
2022ca6:c9::/322ca6:c9:ffff:ffff:ffff:ffff:ffff:ffff
2032ca6:ca::/322ca6:ca:ffff:ffff:ffff:ffff:ffff:ffff
2042ca6:cb::/322ca6:cb:ffff:ffff:ffff:ffff:ffff:ffff
2052ca6:cc::/322ca6:cc:ffff:ffff:ffff:ffff:ffff:ffff
2062ca6:cd::/322ca6:cd:ffff:ffff:ffff:ffff:ffff:ffff
2072ca6:ce::/322ca6:ce:ffff:ffff:ffff:ffff:ffff:ffff
2082ca6:cf::/322ca6:cf:ffff:ffff:ffff:ffff:ffff:ffff
2092ca6:d0::/322ca6:d0:ffff:ffff:ffff:ffff:ffff:ffff
2102ca6:d1::/322ca6:d1:ffff:ffff:ffff:ffff:ffff:ffff
2112ca6:d2::/322ca6:d2:ffff:ffff:ffff:ffff:ffff:ffff
2122ca6:d3::/322ca6:d3:ffff:ffff:ffff:ffff:ffff:ffff
2132ca6:d4::/322ca6:d4:ffff:ffff:ffff:ffff:ffff:ffff
2142ca6:d5::/322ca6:d5:ffff:ffff:ffff:ffff:ffff:ffff
2152ca6:d6::/322ca6:d6:ffff:ffff:ffff:ffff:ffff:ffff
2162ca6:d7::/322ca6:d7:ffff:ffff:ffff:ffff:ffff:ffff
2172ca6:d8::/322ca6:d8:ffff:ffff:ffff:ffff:ffff:ffff
2182ca6:d9::/322ca6:d9:ffff:ffff:ffff:ffff:ffff:ffff
2192ca6:da::/322ca6:da:ffff:ffff:ffff:ffff:ffff:ffff
2202ca6:db::/322ca6:db:ffff:ffff:ffff:ffff:ffff:ffff
2212ca6:dc::/322ca6:dc:ffff:ffff:ffff:ffff:ffff:ffff
2222ca6:dd::/322ca6:dd:ffff:ffff:ffff:ffff:ffff:ffff
2232ca6:de::/322ca6:de:ffff:ffff:ffff:ffff:ffff:ffff
2242ca6:df::/322ca6:df:ffff:ffff:ffff:ffff:ffff:ffff
2252ca6:e0::/322ca6:e0:ffff:ffff:ffff:ffff:ffff:ffff
2262ca6:e1::/322ca6:e1:ffff:ffff:ffff:ffff:ffff:ffff
2272ca6:e2::/322ca6:e2:ffff:ffff:ffff:ffff:ffff:ffff
2282ca6:e3::/322ca6:e3:ffff:ffff:ffff:ffff:ffff:ffff
2292ca6:e4::/322ca6:e4:ffff:ffff:ffff:ffff:ffff:ffff
2302ca6:e5::/322ca6:e5:ffff:ffff:ffff:ffff:ffff:ffff
2312ca6:e6::/322ca6:e6:ffff:ffff:ffff:ffff:ffff:ffff
2322ca6:e7::/322ca6:e7:ffff:ffff:ffff:ffff:ffff:ffff
2332ca6:e8::/322ca6:e8:ffff:ffff:ffff:ffff:ffff:ffff
2342ca6:e9::/322ca6:e9:ffff:ffff:ffff:ffff:ffff:ffff
2352ca6:ea::/322ca6:ea:ffff:ffff:ffff:ffff:ffff:ffff
2362ca6:eb::/322ca6:eb:ffff:ffff:ffff:ffff:ffff:ffff
2372ca6:ec::/322ca6:ec:ffff:ffff:ffff:ffff:ffff:ffff
2382ca6:ed::/322ca6:ed:ffff:ffff:ffff:ffff:ffff:ffff
2392ca6:ee::/322ca6:ee:ffff:ffff:ffff:ffff:ffff:ffff
2402ca6:ef::/322ca6:ef:ffff:ffff:ffff:ffff:ffff:ffff
2412ca6:f0::/322ca6:f0:ffff:ffff:ffff:ffff:ffff:ffff
2422ca6:f1::/322ca6:f1:ffff:ffff:ffff:ffff:ffff:ffff
2432ca6:f2::/322ca6:f2:ffff:ffff:ffff:ffff:ffff:ffff
2442ca6:f3::/322ca6:f3:ffff:ffff:ffff:ffff:ffff:ffff
2452ca6:f4::/322ca6:f4:ffff:ffff:ffff:ffff:ffff:ffff
2462ca6:f5::/322ca6:f5:ffff:ffff:ffff:ffff:ffff:ffff
2472ca6:f6::/322ca6:f6:ffff:ffff:ffff:ffff:ffff:ffff
2482ca6:f7::/322ca6:f7:ffff:ffff:ffff:ffff:ffff:ffff
2492ca6:f8::/322ca6:f8:ffff:ffff:ffff:ffff:ffff:ffff
2502ca6:f9::/322ca6:f9:ffff:ffff:ffff:ffff:ffff:ffff
2512ca6:fa::/322ca6:fa:ffff:ffff:ffff:ffff:ffff:ffff
2522ca6:fb::/322ca6:fb:ffff:ffff:ffff:ffff:ffff:ffff
2532ca6:fc::/322ca6:fc:ffff:ffff:ffff:ffff:ffff:ffff
2542ca6:fd::/322ca6:fd:ffff:ffff:ffff:ffff:ffff:ffff
2552ca6:fe::/322ca6:fe:ffff:ffff:ffff:ffff:ffff:ffff
2562ca6:ff::/322ca6: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.