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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
2030::/16
First address
2030::
Last address
2030: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
2030:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
0.3.0.2.ip6.arpa
Split into smaller subnets/32
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

2030::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
12030::/322030:0:ffff:ffff:ffff:ffff:ffff:ffff
22030:1::/322030:1:ffff:ffff:ffff:ffff:ffff:ffff
32030:2::/322030:2:ffff:ffff:ffff:ffff:ffff:ffff
42030:3::/322030:3:ffff:ffff:ffff:ffff:ffff:ffff
52030:4::/322030:4:ffff:ffff:ffff:ffff:ffff:ffff
62030:5::/322030:5:ffff:ffff:ffff:ffff:ffff:ffff
72030:6::/322030:6:ffff:ffff:ffff:ffff:ffff:ffff
82030:7::/322030:7:ffff:ffff:ffff:ffff:ffff:ffff
92030:8::/322030:8:ffff:ffff:ffff:ffff:ffff:ffff
102030:9::/322030:9:ffff:ffff:ffff:ffff:ffff:ffff
112030:a::/322030:a:ffff:ffff:ffff:ffff:ffff:ffff
122030:b::/322030:b:ffff:ffff:ffff:ffff:ffff:ffff
132030:c::/322030:c:ffff:ffff:ffff:ffff:ffff:ffff
142030:d::/322030:d:ffff:ffff:ffff:ffff:ffff:ffff
152030:e::/322030:e:ffff:ffff:ffff:ffff:ffff:ffff
162030:f::/322030:f:ffff:ffff:ffff:ffff:ffff:ffff
172030:10::/322030:10:ffff:ffff:ffff:ffff:ffff:ffff
182030:11::/322030:11:ffff:ffff:ffff:ffff:ffff:ffff
192030:12::/322030:12:ffff:ffff:ffff:ffff:ffff:ffff
202030:13::/322030:13:ffff:ffff:ffff:ffff:ffff:ffff
212030:14::/322030:14:ffff:ffff:ffff:ffff:ffff:ffff
222030:15::/322030:15:ffff:ffff:ffff:ffff:ffff:ffff
232030:16::/322030:16:ffff:ffff:ffff:ffff:ffff:ffff
242030:17::/322030:17:ffff:ffff:ffff:ffff:ffff:ffff
252030:18::/322030:18:ffff:ffff:ffff:ffff:ffff:ffff
262030:19::/322030:19:ffff:ffff:ffff:ffff:ffff:ffff
272030:1a::/322030:1a:ffff:ffff:ffff:ffff:ffff:ffff
282030:1b::/322030:1b:ffff:ffff:ffff:ffff:ffff:ffff
292030:1c::/322030:1c:ffff:ffff:ffff:ffff:ffff:ffff
302030:1d::/322030:1d:ffff:ffff:ffff:ffff:ffff:ffff
312030:1e::/322030:1e:ffff:ffff:ffff:ffff:ffff:ffff
322030:1f::/322030:1f:ffff:ffff:ffff:ffff:ffff:ffff
332030:20::/322030:20:ffff:ffff:ffff:ffff:ffff:ffff
342030:21::/322030:21:ffff:ffff:ffff:ffff:ffff:ffff
352030:22::/322030:22:ffff:ffff:ffff:ffff:ffff:ffff
362030:23::/322030:23:ffff:ffff:ffff:ffff:ffff:ffff
372030:24::/322030:24:ffff:ffff:ffff:ffff:ffff:ffff
382030:25::/322030:25:ffff:ffff:ffff:ffff:ffff:ffff
392030:26::/322030:26:ffff:ffff:ffff:ffff:ffff:ffff
402030:27::/322030:27:ffff:ffff:ffff:ffff:ffff:ffff
412030:28::/322030:28:ffff:ffff:ffff:ffff:ffff:ffff
422030:29::/322030:29:ffff:ffff:ffff:ffff:ffff:ffff
432030:2a::/322030:2a:ffff:ffff:ffff:ffff:ffff:ffff
442030:2b::/322030:2b:ffff:ffff:ffff:ffff:ffff:ffff
452030:2c::/322030:2c:ffff:ffff:ffff:ffff:ffff:ffff
462030:2d::/322030:2d:ffff:ffff:ffff:ffff:ffff:ffff
472030:2e::/322030:2e:ffff:ffff:ffff:ffff:ffff:ffff
482030:2f::/322030:2f:ffff:ffff:ffff:ffff:ffff:ffff
492030:30::/322030:30:ffff:ffff:ffff:ffff:ffff:ffff
502030:31::/322030:31:ffff:ffff:ffff:ffff:ffff:ffff
512030:32::/322030:32:ffff:ffff:ffff:ffff:ffff:ffff
522030:33::/322030:33:ffff:ffff:ffff:ffff:ffff:ffff
532030:34::/322030:34:ffff:ffff:ffff:ffff:ffff:ffff
542030:35::/322030:35:ffff:ffff:ffff:ffff:ffff:ffff
552030:36::/322030:36:ffff:ffff:ffff:ffff:ffff:ffff
562030:37::/322030:37:ffff:ffff:ffff:ffff:ffff:ffff
572030:38::/322030:38:ffff:ffff:ffff:ffff:ffff:ffff
582030:39::/322030:39:ffff:ffff:ffff:ffff:ffff:ffff
592030:3a::/322030:3a:ffff:ffff:ffff:ffff:ffff:ffff
602030:3b::/322030:3b:ffff:ffff:ffff:ffff:ffff:ffff
612030:3c::/322030:3c:ffff:ffff:ffff:ffff:ffff:ffff
622030:3d::/322030:3d:ffff:ffff:ffff:ffff:ffff:ffff
632030:3e::/322030:3e:ffff:ffff:ffff:ffff:ffff:ffff
642030:3f::/322030:3f:ffff:ffff:ffff:ffff:ffff:ffff
652030:40::/322030:40:ffff:ffff:ffff:ffff:ffff:ffff
662030:41::/322030:41:ffff:ffff:ffff:ffff:ffff:ffff
672030:42::/322030:42:ffff:ffff:ffff:ffff:ffff:ffff
682030:43::/322030:43:ffff:ffff:ffff:ffff:ffff:ffff
692030:44::/322030:44:ffff:ffff:ffff:ffff:ffff:ffff
702030:45::/322030:45:ffff:ffff:ffff:ffff:ffff:ffff
712030:46::/322030:46:ffff:ffff:ffff:ffff:ffff:ffff
722030:47::/322030:47:ffff:ffff:ffff:ffff:ffff:ffff
732030:48::/322030:48:ffff:ffff:ffff:ffff:ffff:ffff
742030:49::/322030:49:ffff:ffff:ffff:ffff:ffff:ffff
752030:4a::/322030:4a:ffff:ffff:ffff:ffff:ffff:ffff
762030:4b::/322030:4b:ffff:ffff:ffff:ffff:ffff:ffff
772030:4c::/322030:4c:ffff:ffff:ffff:ffff:ffff:ffff
782030:4d::/322030:4d:ffff:ffff:ffff:ffff:ffff:ffff
792030:4e::/322030:4e:ffff:ffff:ffff:ffff:ffff:ffff
802030:4f::/322030:4f:ffff:ffff:ffff:ffff:ffff:ffff
812030:50::/322030:50:ffff:ffff:ffff:ffff:ffff:ffff
822030:51::/322030:51:ffff:ffff:ffff:ffff:ffff:ffff
832030:52::/322030:52:ffff:ffff:ffff:ffff:ffff:ffff
842030:53::/322030:53:ffff:ffff:ffff:ffff:ffff:ffff
852030:54::/322030:54:ffff:ffff:ffff:ffff:ffff:ffff
862030:55::/322030:55:ffff:ffff:ffff:ffff:ffff:ffff
872030:56::/322030:56:ffff:ffff:ffff:ffff:ffff:ffff
882030:57::/322030:57:ffff:ffff:ffff:ffff:ffff:ffff
892030:58::/322030:58:ffff:ffff:ffff:ffff:ffff:ffff
902030:59::/322030:59:ffff:ffff:ffff:ffff:ffff:ffff
912030:5a::/322030:5a:ffff:ffff:ffff:ffff:ffff:ffff
922030:5b::/322030:5b:ffff:ffff:ffff:ffff:ffff:ffff
932030:5c::/322030:5c:ffff:ffff:ffff:ffff:ffff:ffff
942030:5d::/322030:5d:ffff:ffff:ffff:ffff:ffff:ffff
952030:5e::/322030:5e:ffff:ffff:ffff:ffff:ffff:ffff
962030:5f::/322030:5f:ffff:ffff:ffff:ffff:ffff:ffff
972030:60::/322030:60:ffff:ffff:ffff:ffff:ffff:ffff
982030:61::/322030:61:ffff:ffff:ffff:ffff:ffff:ffff
992030:62::/322030:62:ffff:ffff:ffff:ffff:ffff:ffff
1002030:63::/322030:63:ffff:ffff:ffff:ffff:ffff:ffff
1012030:64::/322030:64:ffff:ffff:ffff:ffff:ffff:ffff
1022030:65::/322030:65:ffff:ffff:ffff:ffff:ffff:ffff
1032030:66::/322030:66:ffff:ffff:ffff:ffff:ffff:ffff
1042030:67::/322030:67:ffff:ffff:ffff:ffff:ffff:ffff
1052030:68::/322030:68:ffff:ffff:ffff:ffff:ffff:ffff
1062030:69::/322030:69:ffff:ffff:ffff:ffff:ffff:ffff
1072030:6a::/322030:6a:ffff:ffff:ffff:ffff:ffff:ffff
1082030:6b::/322030:6b:ffff:ffff:ffff:ffff:ffff:ffff
1092030:6c::/322030:6c:ffff:ffff:ffff:ffff:ffff:ffff
1102030:6d::/322030:6d:ffff:ffff:ffff:ffff:ffff:ffff
1112030:6e::/322030:6e:ffff:ffff:ffff:ffff:ffff:ffff
1122030:6f::/322030:6f:ffff:ffff:ffff:ffff:ffff:ffff
1132030:70::/322030:70:ffff:ffff:ffff:ffff:ffff:ffff
1142030:71::/322030:71:ffff:ffff:ffff:ffff:ffff:ffff
1152030:72::/322030:72:ffff:ffff:ffff:ffff:ffff:ffff
1162030:73::/322030:73:ffff:ffff:ffff:ffff:ffff:ffff
1172030:74::/322030:74:ffff:ffff:ffff:ffff:ffff:ffff
1182030:75::/322030:75:ffff:ffff:ffff:ffff:ffff:ffff
1192030:76::/322030:76:ffff:ffff:ffff:ffff:ffff:ffff
1202030:77::/322030:77:ffff:ffff:ffff:ffff:ffff:ffff
1212030:78::/322030:78:ffff:ffff:ffff:ffff:ffff:ffff
1222030:79::/322030:79:ffff:ffff:ffff:ffff:ffff:ffff
1232030:7a::/322030:7a:ffff:ffff:ffff:ffff:ffff:ffff
1242030:7b::/322030:7b:ffff:ffff:ffff:ffff:ffff:ffff
1252030:7c::/322030:7c:ffff:ffff:ffff:ffff:ffff:ffff
1262030:7d::/322030:7d:ffff:ffff:ffff:ffff:ffff:ffff
1272030:7e::/322030:7e:ffff:ffff:ffff:ffff:ffff:ffff
1282030:7f::/322030:7f:ffff:ffff:ffff:ffff:ffff:ffff
1292030:80::/322030:80:ffff:ffff:ffff:ffff:ffff:ffff
1302030:81::/322030:81:ffff:ffff:ffff:ffff:ffff:ffff
1312030:82::/322030:82:ffff:ffff:ffff:ffff:ffff:ffff
1322030:83::/322030:83:ffff:ffff:ffff:ffff:ffff:ffff
1332030:84::/322030:84:ffff:ffff:ffff:ffff:ffff:ffff
1342030:85::/322030:85:ffff:ffff:ffff:ffff:ffff:ffff
1352030:86::/322030:86:ffff:ffff:ffff:ffff:ffff:ffff
1362030:87::/322030:87:ffff:ffff:ffff:ffff:ffff:ffff
1372030:88::/322030:88:ffff:ffff:ffff:ffff:ffff:ffff
1382030:89::/322030:89:ffff:ffff:ffff:ffff:ffff:ffff
1392030:8a::/322030:8a:ffff:ffff:ffff:ffff:ffff:ffff
1402030:8b::/322030:8b:ffff:ffff:ffff:ffff:ffff:ffff
1412030:8c::/322030:8c:ffff:ffff:ffff:ffff:ffff:ffff
1422030:8d::/322030:8d:ffff:ffff:ffff:ffff:ffff:ffff
1432030:8e::/322030:8e:ffff:ffff:ffff:ffff:ffff:ffff
1442030:8f::/322030:8f:ffff:ffff:ffff:ffff:ffff:ffff
1452030:90::/322030:90:ffff:ffff:ffff:ffff:ffff:ffff
1462030:91::/322030:91:ffff:ffff:ffff:ffff:ffff:ffff
1472030:92::/322030:92:ffff:ffff:ffff:ffff:ffff:ffff
1482030:93::/322030:93:ffff:ffff:ffff:ffff:ffff:ffff
1492030:94::/322030:94:ffff:ffff:ffff:ffff:ffff:ffff
1502030:95::/322030:95:ffff:ffff:ffff:ffff:ffff:ffff
1512030:96::/322030:96:ffff:ffff:ffff:ffff:ffff:ffff
1522030:97::/322030:97:ffff:ffff:ffff:ffff:ffff:ffff
1532030:98::/322030:98:ffff:ffff:ffff:ffff:ffff:ffff
1542030:99::/322030:99:ffff:ffff:ffff:ffff:ffff:ffff
1552030:9a::/322030:9a:ffff:ffff:ffff:ffff:ffff:ffff
1562030:9b::/322030:9b:ffff:ffff:ffff:ffff:ffff:ffff
1572030:9c::/322030:9c:ffff:ffff:ffff:ffff:ffff:ffff
1582030:9d::/322030:9d:ffff:ffff:ffff:ffff:ffff:ffff
1592030:9e::/322030:9e:ffff:ffff:ffff:ffff:ffff:ffff
1602030:9f::/322030:9f:ffff:ffff:ffff:ffff:ffff:ffff
1612030:a0::/322030:a0:ffff:ffff:ffff:ffff:ffff:ffff
1622030:a1::/322030:a1:ffff:ffff:ffff:ffff:ffff:ffff
1632030:a2::/322030:a2:ffff:ffff:ffff:ffff:ffff:ffff
1642030:a3::/322030:a3:ffff:ffff:ffff:ffff:ffff:ffff
1652030:a4::/322030:a4:ffff:ffff:ffff:ffff:ffff:ffff
1662030:a5::/322030:a5:ffff:ffff:ffff:ffff:ffff:ffff
1672030:a6::/322030:a6:ffff:ffff:ffff:ffff:ffff:ffff
1682030:a7::/322030:a7:ffff:ffff:ffff:ffff:ffff:ffff
1692030:a8::/322030:a8:ffff:ffff:ffff:ffff:ffff:ffff
1702030:a9::/322030:a9:ffff:ffff:ffff:ffff:ffff:ffff
1712030:aa::/322030:aa:ffff:ffff:ffff:ffff:ffff:ffff
1722030:ab::/322030:ab:ffff:ffff:ffff:ffff:ffff:ffff
1732030:ac::/322030:ac:ffff:ffff:ffff:ffff:ffff:ffff
1742030:ad::/322030:ad:ffff:ffff:ffff:ffff:ffff:ffff
1752030:ae::/322030:ae:ffff:ffff:ffff:ffff:ffff:ffff
1762030:af::/322030:af:ffff:ffff:ffff:ffff:ffff:ffff
1772030:b0::/322030:b0:ffff:ffff:ffff:ffff:ffff:ffff
1782030:b1::/322030:b1:ffff:ffff:ffff:ffff:ffff:ffff
1792030:b2::/322030:b2:ffff:ffff:ffff:ffff:ffff:ffff
1802030:b3::/322030:b3:ffff:ffff:ffff:ffff:ffff:ffff
1812030:b4::/322030:b4:ffff:ffff:ffff:ffff:ffff:ffff
1822030:b5::/322030:b5:ffff:ffff:ffff:ffff:ffff:ffff
1832030:b6::/322030:b6:ffff:ffff:ffff:ffff:ffff:ffff
1842030:b7::/322030:b7:ffff:ffff:ffff:ffff:ffff:ffff
1852030:b8::/322030:b8:ffff:ffff:ffff:ffff:ffff:ffff
1862030:b9::/322030:b9:ffff:ffff:ffff:ffff:ffff:ffff
1872030:ba::/322030:ba:ffff:ffff:ffff:ffff:ffff:ffff
1882030:bb::/322030:bb:ffff:ffff:ffff:ffff:ffff:ffff
1892030:bc::/322030:bc:ffff:ffff:ffff:ffff:ffff:ffff
1902030:bd::/322030:bd:ffff:ffff:ffff:ffff:ffff:ffff
1912030:be::/322030:be:ffff:ffff:ffff:ffff:ffff:ffff
1922030:bf::/322030:bf:ffff:ffff:ffff:ffff:ffff:ffff
1932030:c0::/322030:c0:ffff:ffff:ffff:ffff:ffff:ffff
1942030:c1::/322030:c1:ffff:ffff:ffff:ffff:ffff:ffff
1952030:c2::/322030:c2:ffff:ffff:ffff:ffff:ffff:ffff
1962030:c3::/322030:c3:ffff:ffff:ffff:ffff:ffff:ffff
1972030:c4::/322030:c4:ffff:ffff:ffff:ffff:ffff:ffff
1982030:c5::/322030:c5:ffff:ffff:ffff:ffff:ffff:ffff
1992030:c6::/322030:c6:ffff:ffff:ffff:ffff:ffff:ffff
2002030:c7::/322030:c7:ffff:ffff:ffff:ffff:ffff:ffff
2012030:c8::/322030:c8:ffff:ffff:ffff:ffff:ffff:ffff
2022030:c9::/322030:c9:ffff:ffff:ffff:ffff:ffff:ffff
2032030:ca::/322030:ca:ffff:ffff:ffff:ffff:ffff:ffff
2042030:cb::/322030:cb:ffff:ffff:ffff:ffff:ffff:ffff
2052030:cc::/322030:cc:ffff:ffff:ffff:ffff:ffff:ffff
2062030:cd::/322030:cd:ffff:ffff:ffff:ffff:ffff:ffff
2072030:ce::/322030:ce:ffff:ffff:ffff:ffff:ffff:ffff
2082030:cf::/322030:cf:ffff:ffff:ffff:ffff:ffff:ffff
2092030:d0::/322030:d0:ffff:ffff:ffff:ffff:ffff:ffff
2102030:d1::/322030:d1:ffff:ffff:ffff:ffff:ffff:ffff
2112030:d2::/322030:d2:ffff:ffff:ffff:ffff:ffff:ffff
2122030:d3::/322030:d3:ffff:ffff:ffff:ffff:ffff:ffff
2132030:d4::/322030:d4:ffff:ffff:ffff:ffff:ffff:ffff
2142030:d5::/322030:d5:ffff:ffff:ffff:ffff:ffff:ffff
2152030:d6::/322030:d6:ffff:ffff:ffff:ffff:ffff:ffff
2162030:d7::/322030:d7:ffff:ffff:ffff:ffff:ffff:ffff
2172030:d8::/322030:d8:ffff:ffff:ffff:ffff:ffff:ffff
2182030:d9::/322030:d9:ffff:ffff:ffff:ffff:ffff:ffff
2192030:da::/322030:da:ffff:ffff:ffff:ffff:ffff:ffff
2202030:db::/322030:db:ffff:ffff:ffff:ffff:ffff:ffff
2212030:dc::/322030:dc:ffff:ffff:ffff:ffff:ffff:ffff
2222030:dd::/322030:dd:ffff:ffff:ffff:ffff:ffff:ffff
2232030:de::/322030:de:ffff:ffff:ffff:ffff:ffff:ffff
2242030:df::/322030:df:ffff:ffff:ffff:ffff:ffff:ffff
2252030:e0::/322030:e0:ffff:ffff:ffff:ffff:ffff:ffff
2262030:e1::/322030:e1:ffff:ffff:ffff:ffff:ffff:ffff
2272030:e2::/322030:e2:ffff:ffff:ffff:ffff:ffff:ffff
2282030:e3::/322030:e3:ffff:ffff:ffff:ffff:ffff:ffff
2292030:e4::/322030:e4:ffff:ffff:ffff:ffff:ffff:ffff
2302030:e5::/322030:e5:ffff:ffff:ffff:ffff:ffff:ffff
2312030:e6::/322030:e6:ffff:ffff:ffff:ffff:ffff:ffff
2322030:e7::/322030:e7:ffff:ffff:ffff:ffff:ffff:ffff
2332030:e8::/322030:e8:ffff:ffff:ffff:ffff:ffff:ffff
2342030:e9::/322030:e9:ffff:ffff:ffff:ffff:ffff:ffff
2352030:ea::/322030:ea:ffff:ffff:ffff:ffff:ffff:ffff
2362030:eb::/322030:eb:ffff:ffff:ffff:ffff:ffff:ffff
2372030:ec::/322030:ec:ffff:ffff:ffff:ffff:ffff:ffff
2382030:ed::/322030:ed:ffff:ffff:ffff:ffff:ffff:ffff
2392030:ee::/322030:ee:ffff:ffff:ffff:ffff:ffff:ffff
2402030:ef::/322030:ef:ffff:ffff:ffff:ffff:ffff:ffff
2412030:f0::/322030:f0:ffff:ffff:ffff:ffff:ffff:ffff
2422030:f1::/322030:f1:ffff:ffff:ffff:ffff:ffff:ffff
2432030:f2::/322030:f2:ffff:ffff:ffff:ffff:ffff:ffff
2442030:f3::/322030:f3:ffff:ffff:ffff:ffff:ffff:ffff
2452030:f4::/322030:f4:ffff:ffff:ffff:ffff:ffff:ffff
2462030:f5::/322030:f5:ffff:ffff:ffff:ffff:ffff:ffff
2472030:f6::/322030:f6:ffff:ffff:ffff:ffff:ffff:ffff
2482030:f7::/322030:f7:ffff:ffff:ffff:ffff:ffff:ffff
2492030:f8::/322030:f8:ffff:ffff:ffff:ffff:ffff:ffff
2502030:f9::/322030:f9:ffff:ffff:ffff:ffff:ffff:ffff
2512030:fa::/322030:fa:ffff:ffff:ffff:ffff:ffff:ffff
2522030:fb::/322030:fb:ffff:ffff:ffff:ffff:ffff:ffff
2532030:fc::/322030:fc:ffff:ffff:ffff:ffff:ffff:ffff
2542030:fd::/322030:fd:ffff:ffff:ffff:ffff:ffff:ffff
2552030:fe::/322030:fe:ffff:ffff:ffff:ffff:ffff:ffff
2562030:ff::/322030: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.