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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
2090::/16
First address
2090::
Last address
2090: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
2090:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
0.9.0.2.ip6.arpa
Split into smaller subnets/32
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

2090::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
12090::/322090:0:ffff:ffff:ffff:ffff:ffff:ffff
22090:1::/322090:1:ffff:ffff:ffff:ffff:ffff:ffff
32090:2::/322090:2:ffff:ffff:ffff:ffff:ffff:ffff
42090:3::/322090:3:ffff:ffff:ffff:ffff:ffff:ffff
52090:4::/322090:4:ffff:ffff:ffff:ffff:ffff:ffff
62090:5::/322090:5:ffff:ffff:ffff:ffff:ffff:ffff
72090:6::/322090:6:ffff:ffff:ffff:ffff:ffff:ffff
82090:7::/322090:7:ffff:ffff:ffff:ffff:ffff:ffff
92090:8::/322090:8:ffff:ffff:ffff:ffff:ffff:ffff
102090:9::/322090:9:ffff:ffff:ffff:ffff:ffff:ffff
112090:a::/322090:a:ffff:ffff:ffff:ffff:ffff:ffff
122090:b::/322090:b:ffff:ffff:ffff:ffff:ffff:ffff
132090:c::/322090:c:ffff:ffff:ffff:ffff:ffff:ffff
142090:d::/322090:d:ffff:ffff:ffff:ffff:ffff:ffff
152090:e::/322090:e:ffff:ffff:ffff:ffff:ffff:ffff
162090:f::/322090:f:ffff:ffff:ffff:ffff:ffff:ffff
172090:10::/322090:10:ffff:ffff:ffff:ffff:ffff:ffff
182090:11::/322090:11:ffff:ffff:ffff:ffff:ffff:ffff
192090:12::/322090:12:ffff:ffff:ffff:ffff:ffff:ffff
202090:13::/322090:13:ffff:ffff:ffff:ffff:ffff:ffff
212090:14::/322090:14:ffff:ffff:ffff:ffff:ffff:ffff
222090:15::/322090:15:ffff:ffff:ffff:ffff:ffff:ffff
232090:16::/322090:16:ffff:ffff:ffff:ffff:ffff:ffff
242090:17::/322090:17:ffff:ffff:ffff:ffff:ffff:ffff
252090:18::/322090:18:ffff:ffff:ffff:ffff:ffff:ffff
262090:19::/322090:19:ffff:ffff:ffff:ffff:ffff:ffff
272090:1a::/322090:1a:ffff:ffff:ffff:ffff:ffff:ffff
282090:1b::/322090:1b:ffff:ffff:ffff:ffff:ffff:ffff
292090:1c::/322090:1c:ffff:ffff:ffff:ffff:ffff:ffff
302090:1d::/322090:1d:ffff:ffff:ffff:ffff:ffff:ffff
312090:1e::/322090:1e:ffff:ffff:ffff:ffff:ffff:ffff
322090:1f::/322090:1f:ffff:ffff:ffff:ffff:ffff:ffff
332090:20::/322090:20:ffff:ffff:ffff:ffff:ffff:ffff
342090:21::/322090:21:ffff:ffff:ffff:ffff:ffff:ffff
352090:22::/322090:22:ffff:ffff:ffff:ffff:ffff:ffff
362090:23::/322090:23:ffff:ffff:ffff:ffff:ffff:ffff
372090:24::/322090:24:ffff:ffff:ffff:ffff:ffff:ffff
382090:25::/322090:25:ffff:ffff:ffff:ffff:ffff:ffff
392090:26::/322090:26:ffff:ffff:ffff:ffff:ffff:ffff
402090:27::/322090:27:ffff:ffff:ffff:ffff:ffff:ffff
412090:28::/322090:28:ffff:ffff:ffff:ffff:ffff:ffff
422090:29::/322090:29:ffff:ffff:ffff:ffff:ffff:ffff
432090:2a::/322090:2a:ffff:ffff:ffff:ffff:ffff:ffff
442090:2b::/322090:2b:ffff:ffff:ffff:ffff:ffff:ffff
452090:2c::/322090:2c:ffff:ffff:ffff:ffff:ffff:ffff
462090:2d::/322090:2d:ffff:ffff:ffff:ffff:ffff:ffff
472090:2e::/322090:2e:ffff:ffff:ffff:ffff:ffff:ffff
482090:2f::/322090:2f:ffff:ffff:ffff:ffff:ffff:ffff
492090:30::/322090:30:ffff:ffff:ffff:ffff:ffff:ffff
502090:31::/322090:31:ffff:ffff:ffff:ffff:ffff:ffff
512090:32::/322090:32:ffff:ffff:ffff:ffff:ffff:ffff
522090:33::/322090:33:ffff:ffff:ffff:ffff:ffff:ffff
532090:34::/322090:34:ffff:ffff:ffff:ffff:ffff:ffff
542090:35::/322090:35:ffff:ffff:ffff:ffff:ffff:ffff
552090:36::/322090:36:ffff:ffff:ffff:ffff:ffff:ffff
562090:37::/322090:37:ffff:ffff:ffff:ffff:ffff:ffff
572090:38::/322090:38:ffff:ffff:ffff:ffff:ffff:ffff
582090:39::/322090:39:ffff:ffff:ffff:ffff:ffff:ffff
592090:3a::/322090:3a:ffff:ffff:ffff:ffff:ffff:ffff
602090:3b::/322090:3b:ffff:ffff:ffff:ffff:ffff:ffff
612090:3c::/322090:3c:ffff:ffff:ffff:ffff:ffff:ffff
622090:3d::/322090:3d:ffff:ffff:ffff:ffff:ffff:ffff
632090:3e::/322090:3e:ffff:ffff:ffff:ffff:ffff:ffff
642090:3f::/322090:3f:ffff:ffff:ffff:ffff:ffff:ffff
652090:40::/322090:40:ffff:ffff:ffff:ffff:ffff:ffff
662090:41::/322090:41:ffff:ffff:ffff:ffff:ffff:ffff
672090:42::/322090:42:ffff:ffff:ffff:ffff:ffff:ffff
682090:43::/322090:43:ffff:ffff:ffff:ffff:ffff:ffff
692090:44::/322090:44:ffff:ffff:ffff:ffff:ffff:ffff
702090:45::/322090:45:ffff:ffff:ffff:ffff:ffff:ffff
712090:46::/322090:46:ffff:ffff:ffff:ffff:ffff:ffff
722090:47::/322090:47:ffff:ffff:ffff:ffff:ffff:ffff
732090:48::/322090:48:ffff:ffff:ffff:ffff:ffff:ffff
742090:49::/322090:49:ffff:ffff:ffff:ffff:ffff:ffff
752090:4a::/322090:4a:ffff:ffff:ffff:ffff:ffff:ffff
762090:4b::/322090:4b:ffff:ffff:ffff:ffff:ffff:ffff
772090:4c::/322090:4c:ffff:ffff:ffff:ffff:ffff:ffff
782090:4d::/322090:4d:ffff:ffff:ffff:ffff:ffff:ffff
792090:4e::/322090:4e:ffff:ffff:ffff:ffff:ffff:ffff
802090:4f::/322090:4f:ffff:ffff:ffff:ffff:ffff:ffff
812090:50::/322090:50:ffff:ffff:ffff:ffff:ffff:ffff
822090:51::/322090:51:ffff:ffff:ffff:ffff:ffff:ffff
832090:52::/322090:52:ffff:ffff:ffff:ffff:ffff:ffff
842090:53::/322090:53:ffff:ffff:ffff:ffff:ffff:ffff
852090:54::/322090:54:ffff:ffff:ffff:ffff:ffff:ffff
862090:55::/322090:55:ffff:ffff:ffff:ffff:ffff:ffff
872090:56::/322090:56:ffff:ffff:ffff:ffff:ffff:ffff
882090:57::/322090:57:ffff:ffff:ffff:ffff:ffff:ffff
892090:58::/322090:58:ffff:ffff:ffff:ffff:ffff:ffff
902090:59::/322090:59:ffff:ffff:ffff:ffff:ffff:ffff
912090:5a::/322090:5a:ffff:ffff:ffff:ffff:ffff:ffff
922090:5b::/322090:5b:ffff:ffff:ffff:ffff:ffff:ffff
932090:5c::/322090:5c:ffff:ffff:ffff:ffff:ffff:ffff
942090:5d::/322090:5d:ffff:ffff:ffff:ffff:ffff:ffff
952090:5e::/322090:5e:ffff:ffff:ffff:ffff:ffff:ffff
962090:5f::/322090:5f:ffff:ffff:ffff:ffff:ffff:ffff
972090:60::/322090:60:ffff:ffff:ffff:ffff:ffff:ffff
982090:61::/322090:61:ffff:ffff:ffff:ffff:ffff:ffff
992090:62::/322090:62:ffff:ffff:ffff:ffff:ffff:ffff
1002090:63::/322090:63:ffff:ffff:ffff:ffff:ffff:ffff
1012090:64::/322090:64:ffff:ffff:ffff:ffff:ffff:ffff
1022090:65::/322090:65:ffff:ffff:ffff:ffff:ffff:ffff
1032090:66::/322090:66:ffff:ffff:ffff:ffff:ffff:ffff
1042090:67::/322090:67:ffff:ffff:ffff:ffff:ffff:ffff
1052090:68::/322090:68:ffff:ffff:ffff:ffff:ffff:ffff
1062090:69::/322090:69:ffff:ffff:ffff:ffff:ffff:ffff
1072090:6a::/322090:6a:ffff:ffff:ffff:ffff:ffff:ffff
1082090:6b::/322090:6b:ffff:ffff:ffff:ffff:ffff:ffff
1092090:6c::/322090:6c:ffff:ffff:ffff:ffff:ffff:ffff
1102090:6d::/322090:6d:ffff:ffff:ffff:ffff:ffff:ffff
1112090:6e::/322090:6e:ffff:ffff:ffff:ffff:ffff:ffff
1122090:6f::/322090:6f:ffff:ffff:ffff:ffff:ffff:ffff
1132090:70::/322090:70:ffff:ffff:ffff:ffff:ffff:ffff
1142090:71::/322090:71:ffff:ffff:ffff:ffff:ffff:ffff
1152090:72::/322090:72:ffff:ffff:ffff:ffff:ffff:ffff
1162090:73::/322090:73:ffff:ffff:ffff:ffff:ffff:ffff
1172090:74::/322090:74:ffff:ffff:ffff:ffff:ffff:ffff
1182090:75::/322090:75:ffff:ffff:ffff:ffff:ffff:ffff
1192090:76::/322090:76:ffff:ffff:ffff:ffff:ffff:ffff
1202090:77::/322090:77:ffff:ffff:ffff:ffff:ffff:ffff
1212090:78::/322090:78:ffff:ffff:ffff:ffff:ffff:ffff
1222090:79::/322090:79:ffff:ffff:ffff:ffff:ffff:ffff
1232090:7a::/322090:7a:ffff:ffff:ffff:ffff:ffff:ffff
1242090:7b::/322090:7b:ffff:ffff:ffff:ffff:ffff:ffff
1252090:7c::/322090:7c:ffff:ffff:ffff:ffff:ffff:ffff
1262090:7d::/322090:7d:ffff:ffff:ffff:ffff:ffff:ffff
1272090:7e::/322090:7e:ffff:ffff:ffff:ffff:ffff:ffff
1282090:7f::/322090:7f:ffff:ffff:ffff:ffff:ffff:ffff
1292090:80::/322090:80:ffff:ffff:ffff:ffff:ffff:ffff
1302090:81::/322090:81:ffff:ffff:ffff:ffff:ffff:ffff
1312090:82::/322090:82:ffff:ffff:ffff:ffff:ffff:ffff
1322090:83::/322090:83:ffff:ffff:ffff:ffff:ffff:ffff
1332090:84::/322090:84:ffff:ffff:ffff:ffff:ffff:ffff
1342090:85::/322090:85:ffff:ffff:ffff:ffff:ffff:ffff
1352090:86::/322090:86:ffff:ffff:ffff:ffff:ffff:ffff
1362090:87::/322090:87:ffff:ffff:ffff:ffff:ffff:ffff
1372090:88::/322090:88:ffff:ffff:ffff:ffff:ffff:ffff
1382090:89::/322090:89:ffff:ffff:ffff:ffff:ffff:ffff
1392090:8a::/322090:8a:ffff:ffff:ffff:ffff:ffff:ffff
1402090:8b::/322090:8b:ffff:ffff:ffff:ffff:ffff:ffff
1412090:8c::/322090:8c:ffff:ffff:ffff:ffff:ffff:ffff
1422090:8d::/322090:8d:ffff:ffff:ffff:ffff:ffff:ffff
1432090:8e::/322090:8e:ffff:ffff:ffff:ffff:ffff:ffff
1442090:8f::/322090:8f:ffff:ffff:ffff:ffff:ffff:ffff
1452090:90::/322090:90:ffff:ffff:ffff:ffff:ffff:ffff
1462090:91::/322090:91:ffff:ffff:ffff:ffff:ffff:ffff
1472090:92::/322090:92:ffff:ffff:ffff:ffff:ffff:ffff
1482090:93::/322090:93:ffff:ffff:ffff:ffff:ffff:ffff
1492090:94::/322090:94:ffff:ffff:ffff:ffff:ffff:ffff
1502090:95::/322090:95:ffff:ffff:ffff:ffff:ffff:ffff
1512090:96::/322090:96:ffff:ffff:ffff:ffff:ffff:ffff
1522090:97::/322090:97:ffff:ffff:ffff:ffff:ffff:ffff
1532090:98::/322090:98:ffff:ffff:ffff:ffff:ffff:ffff
1542090:99::/322090:99:ffff:ffff:ffff:ffff:ffff:ffff
1552090:9a::/322090:9a:ffff:ffff:ffff:ffff:ffff:ffff
1562090:9b::/322090:9b:ffff:ffff:ffff:ffff:ffff:ffff
1572090:9c::/322090:9c:ffff:ffff:ffff:ffff:ffff:ffff
1582090:9d::/322090:9d:ffff:ffff:ffff:ffff:ffff:ffff
1592090:9e::/322090:9e:ffff:ffff:ffff:ffff:ffff:ffff
1602090:9f::/322090:9f:ffff:ffff:ffff:ffff:ffff:ffff
1612090:a0::/322090:a0:ffff:ffff:ffff:ffff:ffff:ffff
1622090:a1::/322090:a1:ffff:ffff:ffff:ffff:ffff:ffff
1632090:a2::/322090:a2:ffff:ffff:ffff:ffff:ffff:ffff
1642090:a3::/322090:a3:ffff:ffff:ffff:ffff:ffff:ffff
1652090:a4::/322090:a4:ffff:ffff:ffff:ffff:ffff:ffff
1662090:a5::/322090:a5:ffff:ffff:ffff:ffff:ffff:ffff
1672090:a6::/322090:a6:ffff:ffff:ffff:ffff:ffff:ffff
1682090:a7::/322090:a7:ffff:ffff:ffff:ffff:ffff:ffff
1692090:a8::/322090:a8:ffff:ffff:ffff:ffff:ffff:ffff
1702090:a9::/322090:a9:ffff:ffff:ffff:ffff:ffff:ffff
1712090:aa::/322090:aa:ffff:ffff:ffff:ffff:ffff:ffff
1722090:ab::/322090:ab:ffff:ffff:ffff:ffff:ffff:ffff
1732090:ac::/322090:ac:ffff:ffff:ffff:ffff:ffff:ffff
1742090:ad::/322090:ad:ffff:ffff:ffff:ffff:ffff:ffff
1752090:ae::/322090:ae:ffff:ffff:ffff:ffff:ffff:ffff
1762090:af::/322090:af:ffff:ffff:ffff:ffff:ffff:ffff
1772090:b0::/322090:b0:ffff:ffff:ffff:ffff:ffff:ffff
1782090:b1::/322090:b1:ffff:ffff:ffff:ffff:ffff:ffff
1792090:b2::/322090:b2:ffff:ffff:ffff:ffff:ffff:ffff
1802090:b3::/322090:b3:ffff:ffff:ffff:ffff:ffff:ffff
1812090:b4::/322090:b4:ffff:ffff:ffff:ffff:ffff:ffff
1822090:b5::/322090:b5:ffff:ffff:ffff:ffff:ffff:ffff
1832090:b6::/322090:b6:ffff:ffff:ffff:ffff:ffff:ffff
1842090:b7::/322090:b7:ffff:ffff:ffff:ffff:ffff:ffff
1852090:b8::/322090:b8:ffff:ffff:ffff:ffff:ffff:ffff
1862090:b9::/322090:b9:ffff:ffff:ffff:ffff:ffff:ffff
1872090:ba::/322090:ba:ffff:ffff:ffff:ffff:ffff:ffff
1882090:bb::/322090:bb:ffff:ffff:ffff:ffff:ffff:ffff
1892090:bc::/322090:bc:ffff:ffff:ffff:ffff:ffff:ffff
1902090:bd::/322090:bd:ffff:ffff:ffff:ffff:ffff:ffff
1912090:be::/322090:be:ffff:ffff:ffff:ffff:ffff:ffff
1922090:bf::/322090:bf:ffff:ffff:ffff:ffff:ffff:ffff
1932090:c0::/322090:c0:ffff:ffff:ffff:ffff:ffff:ffff
1942090:c1::/322090:c1:ffff:ffff:ffff:ffff:ffff:ffff
1952090:c2::/322090:c2:ffff:ffff:ffff:ffff:ffff:ffff
1962090:c3::/322090:c3:ffff:ffff:ffff:ffff:ffff:ffff
1972090:c4::/322090:c4:ffff:ffff:ffff:ffff:ffff:ffff
1982090:c5::/322090:c5:ffff:ffff:ffff:ffff:ffff:ffff
1992090:c6::/322090:c6:ffff:ffff:ffff:ffff:ffff:ffff
2002090:c7::/322090:c7:ffff:ffff:ffff:ffff:ffff:ffff
2012090:c8::/322090:c8:ffff:ffff:ffff:ffff:ffff:ffff
2022090:c9::/322090:c9:ffff:ffff:ffff:ffff:ffff:ffff
2032090:ca::/322090:ca:ffff:ffff:ffff:ffff:ffff:ffff
2042090:cb::/322090:cb:ffff:ffff:ffff:ffff:ffff:ffff
2052090:cc::/322090:cc:ffff:ffff:ffff:ffff:ffff:ffff
2062090:cd::/322090:cd:ffff:ffff:ffff:ffff:ffff:ffff
2072090:ce::/322090:ce:ffff:ffff:ffff:ffff:ffff:ffff
2082090:cf::/322090:cf:ffff:ffff:ffff:ffff:ffff:ffff
2092090:d0::/322090:d0:ffff:ffff:ffff:ffff:ffff:ffff
2102090:d1::/322090:d1:ffff:ffff:ffff:ffff:ffff:ffff
2112090:d2::/322090:d2:ffff:ffff:ffff:ffff:ffff:ffff
2122090:d3::/322090:d3:ffff:ffff:ffff:ffff:ffff:ffff
2132090:d4::/322090:d4:ffff:ffff:ffff:ffff:ffff:ffff
2142090:d5::/322090:d5:ffff:ffff:ffff:ffff:ffff:ffff
2152090:d6::/322090:d6:ffff:ffff:ffff:ffff:ffff:ffff
2162090:d7::/322090:d7:ffff:ffff:ffff:ffff:ffff:ffff
2172090:d8::/322090:d8:ffff:ffff:ffff:ffff:ffff:ffff
2182090:d9::/322090:d9:ffff:ffff:ffff:ffff:ffff:ffff
2192090:da::/322090:da:ffff:ffff:ffff:ffff:ffff:ffff
2202090:db::/322090:db:ffff:ffff:ffff:ffff:ffff:ffff
2212090:dc::/322090:dc:ffff:ffff:ffff:ffff:ffff:ffff
2222090:dd::/322090:dd:ffff:ffff:ffff:ffff:ffff:ffff
2232090:de::/322090:de:ffff:ffff:ffff:ffff:ffff:ffff
2242090:df::/322090:df:ffff:ffff:ffff:ffff:ffff:ffff
2252090:e0::/322090:e0:ffff:ffff:ffff:ffff:ffff:ffff
2262090:e1::/322090:e1:ffff:ffff:ffff:ffff:ffff:ffff
2272090:e2::/322090:e2:ffff:ffff:ffff:ffff:ffff:ffff
2282090:e3::/322090:e3:ffff:ffff:ffff:ffff:ffff:ffff
2292090:e4::/322090:e4:ffff:ffff:ffff:ffff:ffff:ffff
2302090:e5::/322090:e5:ffff:ffff:ffff:ffff:ffff:ffff
2312090:e6::/322090:e6:ffff:ffff:ffff:ffff:ffff:ffff
2322090:e7::/322090:e7:ffff:ffff:ffff:ffff:ffff:ffff
2332090:e8::/322090:e8:ffff:ffff:ffff:ffff:ffff:ffff
2342090:e9::/322090:e9:ffff:ffff:ffff:ffff:ffff:ffff
2352090:ea::/322090:ea:ffff:ffff:ffff:ffff:ffff:ffff
2362090:eb::/322090:eb:ffff:ffff:ffff:ffff:ffff:ffff
2372090:ec::/322090:ec:ffff:ffff:ffff:ffff:ffff:ffff
2382090:ed::/322090:ed:ffff:ffff:ffff:ffff:ffff:ffff
2392090:ee::/322090:ee:ffff:ffff:ffff:ffff:ffff:ffff
2402090:ef::/322090:ef:ffff:ffff:ffff:ffff:ffff:ffff
2412090:f0::/322090:f0:ffff:ffff:ffff:ffff:ffff:ffff
2422090:f1::/322090:f1:ffff:ffff:ffff:ffff:ffff:ffff
2432090:f2::/322090:f2:ffff:ffff:ffff:ffff:ffff:ffff
2442090:f3::/322090:f3:ffff:ffff:ffff:ffff:ffff:ffff
2452090:f4::/322090:f4:ffff:ffff:ffff:ffff:ffff:ffff
2462090:f5::/322090:f5:ffff:ffff:ffff:ffff:ffff:ffff
2472090:f6::/322090:f6:ffff:ffff:ffff:ffff:ffff:ffff
2482090:f7::/322090:f7:ffff:ffff:ffff:ffff:ffff:ffff
2492090:f8::/322090:f8:ffff:ffff:ffff:ffff:ffff:ffff
2502090:f9::/322090:f9:ffff:ffff:ffff:ffff:ffff:ffff
2512090:fa::/322090:fa:ffff:ffff:ffff:ffff:ffff:ffff
2522090:fb::/322090:fb:ffff:ffff:ffff:ffff:ffff:ffff
2532090:fc::/322090:fc:ffff:ffff:ffff:ffff:ffff:ffff
2542090:fd::/322090:fd:ffff:ffff:ffff:ffff:ffff:ffff
2552090:fe::/322090:fe:ffff:ffff:ffff:ffff:ffff:ffff
2562090:ff::/322090: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.