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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
2034::/16
First address
2034::
Last address
2034: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
2034:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
4.3.0.2.ip6.arpa
Split into smaller subnets/32
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

2034::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
12034::/322034:0:ffff:ffff:ffff:ffff:ffff:ffff
22034:1::/322034:1:ffff:ffff:ffff:ffff:ffff:ffff
32034:2::/322034:2:ffff:ffff:ffff:ffff:ffff:ffff
42034:3::/322034:3:ffff:ffff:ffff:ffff:ffff:ffff
52034:4::/322034:4:ffff:ffff:ffff:ffff:ffff:ffff
62034:5::/322034:5:ffff:ffff:ffff:ffff:ffff:ffff
72034:6::/322034:6:ffff:ffff:ffff:ffff:ffff:ffff
82034:7::/322034:7:ffff:ffff:ffff:ffff:ffff:ffff
92034:8::/322034:8:ffff:ffff:ffff:ffff:ffff:ffff
102034:9::/322034:9:ffff:ffff:ffff:ffff:ffff:ffff
112034:a::/322034:a:ffff:ffff:ffff:ffff:ffff:ffff
122034:b::/322034:b:ffff:ffff:ffff:ffff:ffff:ffff
132034:c::/322034:c:ffff:ffff:ffff:ffff:ffff:ffff
142034:d::/322034:d:ffff:ffff:ffff:ffff:ffff:ffff
152034:e::/322034:e:ffff:ffff:ffff:ffff:ffff:ffff
162034:f::/322034:f:ffff:ffff:ffff:ffff:ffff:ffff
172034:10::/322034:10:ffff:ffff:ffff:ffff:ffff:ffff
182034:11::/322034:11:ffff:ffff:ffff:ffff:ffff:ffff
192034:12::/322034:12:ffff:ffff:ffff:ffff:ffff:ffff
202034:13::/322034:13:ffff:ffff:ffff:ffff:ffff:ffff
212034:14::/322034:14:ffff:ffff:ffff:ffff:ffff:ffff
222034:15::/322034:15:ffff:ffff:ffff:ffff:ffff:ffff
232034:16::/322034:16:ffff:ffff:ffff:ffff:ffff:ffff
242034:17::/322034:17:ffff:ffff:ffff:ffff:ffff:ffff
252034:18::/322034:18:ffff:ffff:ffff:ffff:ffff:ffff
262034:19::/322034:19:ffff:ffff:ffff:ffff:ffff:ffff
272034:1a::/322034:1a:ffff:ffff:ffff:ffff:ffff:ffff
282034:1b::/322034:1b:ffff:ffff:ffff:ffff:ffff:ffff
292034:1c::/322034:1c:ffff:ffff:ffff:ffff:ffff:ffff
302034:1d::/322034:1d:ffff:ffff:ffff:ffff:ffff:ffff
312034:1e::/322034:1e:ffff:ffff:ffff:ffff:ffff:ffff
322034:1f::/322034:1f:ffff:ffff:ffff:ffff:ffff:ffff
332034:20::/322034:20:ffff:ffff:ffff:ffff:ffff:ffff
342034:21::/322034:21:ffff:ffff:ffff:ffff:ffff:ffff
352034:22::/322034:22:ffff:ffff:ffff:ffff:ffff:ffff
362034:23::/322034:23:ffff:ffff:ffff:ffff:ffff:ffff
372034:24::/322034:24:ffff:ffff:ffff:ffff:ffff:ffff
382034:25::/322034:25:ffff:ffff:ffff:ffff:ffff:ffff
392034:26::/322034:26:ffff:ffff:ffff:ffff:ffff:ffff
402034:27::/322034:27:ffff:ffff:ffff:ffff:ffff:ffff
412034:28::/322034:28:ffff:ffff:ffff:ffff:ffff:ffff
422034:29::/322034:29:ffff:ffff:ffff:ffff:ffff:ffff
432034:2a::/322034:2a:ffff:ffff:ffff:ffff:ffff:ffff
442034:2b::/322034:2b:ffff:ffff:ffff:ffff:ffff:ffff
452034:2c::/322034:2c:ffff:ffff:ffff:ffff:ffff:ffff
462034:2d::/322034:2d:ffff:ffff:ffff:ffff:ffff:ffff
472034:2e::/322034:2e:ffff:ffff:ffff:ffff:ffff:ffff
482034:2f::/322034:2f:ffff:ffff:ffff:ffff:ffff:ffff
492034:30::/322034:30:ffff:ffff:ffff:ffff:ffff:ffff
502034:31::/322034:31:ffff:ffff:ffff:ffff:ffff:ffff
512034:32::/322034:32:ffff:ffff:ffff:ffff:ffff:ffff
522034:33::/322034:33:ffff:ffff:ffff:ffff:ffff:ffff
532034:34::/322034:34:ffff:ffff:ffff:ffff:ffff:ffff
542034:35::/322034:35:ffff:ffff:ffff:ffff:ffff:ffff
552034:36::/322034:36:ffff:ffff:ffff:ffff:ffff:ffff
562034:37::/322034:37:ffff:ffff:ffff:ffff:ffff:ffff
572034:38::/322034:38:ffff:ffff:ffff:ffff:ffff:ffff
582034:39::/322034:39:ffff:ffff:ffff:ffff:ffff:ffff
592034:3a::/322034:3a:ffff:ffff:ffff:ffff:ffff:ffff
602034:3b::/322034:3b:ffff:ffff:ffff:ffff:ffff:ffff
612034:3c::/322034:3c:ffff:ffff:ffff:ffff:ffff:ffff
622034:3d::/322034:3d:ffff:ffff:ffff:ffff:ffff:ffff
632034:3e::/322034:3e:ffff:ffff:ffff:ffff:ffff:ffff
642034:3f::/322034:3f:ffff:ffff:ffff:ffff:ffff:ffff
652034:40::/322034:40:ffff:ffff:ffff:ffff:ffff:ffff
662034:41::/322034:41:ffff:ffff:ffff:ffff:ffff:ffff
672034:42::/322034:42:ffff:ffff:ffff:ffff:ffff:ffff
682034:43::/322034:43:ffff:ffff:ffff:ffff:ffff:ffff
692034:44::/322034:44:ffff:ffff:ffff:ffff:ffff:ffff
702034:45::/322034:45:ffff:ffff:ffff:ffff:ffff:ffff
712034:46::/322034:46:ffff:ffff:ffff:ffff:ffff:ffff
722034:47::/322034:47:ffff:ffff:ffff:ffff:ffff:ffff
732034:48::/322034:48:ffff:ffff:ffff:ffff:ffff:ffff
742034:49::/322034:49:ffff:ffff:ffff:ffff:ffff:ffff
752034:4a::/322034:4a:ffff:ffff:ffff:ffff:ffff:ffff
762034:4b::/322034:4b:ffff:ffff:ffff:ffff:ffff:ffff
772034:4c::/322034:4c:ffff:ffff:ffff:ffff:ffff:ffff
782034:4d::/322034:4d:ffff:ffff:ffff:ffff:ffff:ffff
792034:4e::/322034:4e:ffff:ffff:ffff:ffff:ffff:ffff
802034:4f::/322034:4f:ffff:ffff:ffff:ffff:ffff:ffff
812034:50::/322034:50:ffff:ffff:ffff:ffff:ffff:ffff
822034:51::/322034:51:ffff:ffff:ffff:ffff:ffff:ffff
832034:52::/322034:52:ffff:ffff:ffff:ffff:ffff:ffff
842034:53::/322034:53:ffff:ffff:ffff:ffff:ffff:ffff
852034:54::/322034:54:ffff:ffff:ffff:ffff:ffff:ffff
862034:55::/322034:55:ffff:ffff:ffff:ffff:ffff:ffff
872034:56::/322034:56:ffff:ffff:ffff:ffff:ffff:ffff
882034:57::/322034:57:ffff:ffff:ffff:ffff:ffff:ffff
892034:58::/322034:58:ffff:ffff:ffff:ffff:ffff:ffff
902034:59::/322034:59:ffff:ffff:ffff:ffff:ffff:ffff
912034:5a::/322034:5a:ffff:ffff:ffff:ffff:ffff:ffff
922034:5b::/322034:5b:ffff:ffff:ffff:ffff:ffff:ffff
932034:5c::/322034:5c:ffff:ffff:ffff:ffff:ffff:ffff
942034:5d::/322034:5d:ffff:ffff:ffff:ffff:ffff:ffff
952034:5e::/322034:5e:ffff:ffff:ffff:ffff:ffff:ffff
962034:5f::/322034:5f:ffff:ffff:ffff:ffff:ffff:ffff
972034:60::/322034:60:ffff:ffff:ffff:ffff:ffff:ffff
982034:61::/322034:61:ffff:ffff:ffff:ffff:ffff:ffff
992034:62::/322034:62:ffff:ffff:ffff:ffff:ffff:ffff
1002034:63::/322034:63:ffff:ffff:ffff:ffff:ffff:ffff
1012034:64::/322034:64:ffff:ffff:ffff:ffff:ffff:ffff
1022034:65::/322034:65:ffff:ffff:ffff:ffff:ffff:ffff
1032034:66::/322034:66:ffff:ffff:ffff:ffff:ffff:ffff
1042034:67::/322034:67:ffff:ffff:ffff:ffff:ffff:ffff
1052034:68::/322034:68:ffff:ffff:ffff:ffff:ffff:ffff
1062034:69::/322034:69:ffff:ffff:ffff:ffff:ffff:ffff
1072034:6a::/322034:6a:ffff:ffff:ffff:ffff:ffff:ffff
1082034:6b::/322034:6b:ffff:ffff:ffff:ffff:ffff:ffff
1092034:6c::/322034:6c:ffff:ffff:ffff:ffff:ffff:ffff
1102034:6d::/322034:6d:ffff:ffff:ffff:ffff:ffff:ffff
1112034:6e::/322034:6e:ffff:ffff:ffff:ffff:ffff:ffff
1122034:6f::/322034:6f:ffff:ffff:ffff:ffff:ffff:ffff
1132034:70::/322034:70:ffff:ffff:ffff:ffff:ffff:ffff
1142034:71::/322034:71:ffff:ffff:ffff:ffff:ffff:ffff
1152034:72::/322034:72:ffff:ffff:ffff:ffff:ffff:ffff
1162034:73::/322034:73:ffff:ffff:ffff:ffff:ffff:ffff
1172034:74::/322034:74:ffff:ffff:ffff:ffff:ffff:ffff
1182034:75::/322034:75:ffff:ffff:ffff:ffff:ffff:ffff
1192034:76::/322034:76:ffff:ffff:ffff:ffff:ffff:ffff
1202034:77::/322034:77:ffff:ffff:ffff:ffff:ffff:ffff
1212034:78::/322034:78:ffff:ffff:ffff:ffff:ffff:ffff
1222034:79::/322034:79:ffff:ffff:ffff:ffff:ffff:ffff
1232034:7a::/322034:7a:ffff:ffff:ffff:ffff:ffff:ffff
1242034:7b::/322034:7b:ffff:ffff:ffff:ffff:ffff:ffff
1252034:7c::/322034:7c:ffff:ffff:ffff:ffff:ffff:ffff
1262034:7d::/322034:7d:ffff:ffff:ffff:ffff:ffff:ffff
1272034:7e::/322034:7e:ffff:ffff:ffff:ffff:ffff:ffff
1282034:7f::/322034:7f:ffff:ffff:ffff:ffff:ffff:ffff
1292034:80::/322034:80:ffff:ffff:ffff:ffff:ffff:ffff
1302034:81::/322034:81:ffff:ffff:ffff:ffff:ffff:ffff
1312034:82::/322034:82:ffff:ffff:ffff:ffff:ffff:ffff
1322034:83::/322034:83:ffff:ffff:ffff:ffff:ffff:ffff
1332034:84::/322034:84:ffff:ffff:ffff:ffff:ffff:ffff
1342034:85::/322034:85:ffff:ffff:ffff:ffff:ffff:ffff
1352034:86::/322034:86:ffff:ffff:ffff:ffff:ffff:ffff
1362034:87::/322034:87:ffff:ffff:ffff:ffff:ffff:ffff
1372034:88::/322034:88:ffff:ffff:ffff:ffff:ffff:ffff
1382034:89::/322034:89:ffff:ffff:ffff:ffff:ffff:ffff
1392034:8a::/322034:8a:ffff:ffff:ffff:ffff:ffff:ffff
1402034:8b::/322034:8b:ffff:ffff:ffff:ffff:ffff:ffff
1412034:8c::/322034:8c:ffff:ffff:ffff:ffff:ffff:ffff
1422034:8d::/322034:8d:ffff:ffff:ffff:ffff:ffff:ffff
1432034:8e::/322034:8e:ffff:ffff:ffff:ffff:ffff:ffff
1442034:8f::/322034:8f:ffff:ffff:ffff:ffff:ffff:ffff
1452034:90::/322034:90:ffff:ffff:ffff:ffff:ffff:ffff
1462034:91::/322034:91:ffff:ffff:ffff:ffff:ffff:ffff
1472034:92::/322034:92:ffff:ffff:ffff:ffff:ffff:ffff
1482034:93::/322034:93:ffff:ffff:ffff:ffff:ffff:ffff
1492034:94::/322034:94:ffff:ffff:ffff:ffff:ffff:ffff
1502034:95::/322034:95:ffff:ffff:ffff:ffff:ffff:ffff
1512034:96::/322034:96:ffff:ffff:ffff:ffff:ffff:ffff
1522034:97::/322034:97:ffff:ffff:ffff:ffff:ffff:ffff
1532034:98::/322034:98:ffff:ffff:ffff:ffff:ffff:ffff
1542034:99::/322034:99:ffff:ffff:ffff:ffff:ffff:ffff
1552034:9a::/322034:9a:ffff:ffff:ffff:ffff:ffff:ffff
1562034:9b::/322034:9b:ffff:ffff:ffff:ffff:ffff:ffff
1572034:9c::/322034:9c:ffff:ffff:ffff:ffff:ffff:ffff
1582034:9d::/322034:9d:ffff:ffff:ffff:ffff:ffff:ffff
1592034:9e::/322034:9e:ffff:ffff:ffff:ffff:ffff:ffff
1602034:9f::/322034:9f:ffff:ffff:ffff:ffff:ffff:ffff
1612034:a0::/322034:a0:ffff:ffff:ffff:ffff:ffff:ffff
1622034:a1::/322034:a1:ffff:ffff:ffff:ffff:ffff:ffff
1632034:a2::/322034:a2:ffff:ffff:ffff:ffff:ffff:ffff
1642034:a3::/322034:a3:ffff:ffff:ffff:ffff:ffff:ffff
1652034:a4::/322034:a4:ffff:ffff:ffff:ffff:ffff:ffff
1662034:a5::/322034:a5:ffff:ffff:ffff:ffff:ffff:ffff
1672034:a6::/322034:a6:ffff:ffff:ffff:ffff:ffff:ffff
1682034:a7::/322034:a7:ffff:ffff:ffff:ffff:ffff:ffff
1692034:a8::/322034:a8:ffff:ffff:ffff:ffff:ffff:ffff
1702034:a9::/322034:a9:ffff:ffff:ffff:ffff:ffff:ffff
1712034:aa::/322034:aa:ffff:ffff:ffff:ffff:ffff:ffff
1722034:ab::/322034:ab:ffff:ffff:ffff:ffff:ffff:ffff
1732034:ac::/322034:ac:ffff:ffff:ffff:ffff:ffff:ffff
1742034:ad::/322034:ad:ffff:ffff:ffff:ffff:ffff:ffff
1752034:ae::/322034:ae:ffff:ffff:ffff:ffff:ffff:ffff
1762034:af::/322034:af:ffff:ffff:ffff:ffff:ffff:ffff
1772034:b0::/322034:b0:ffff:ffff:ffff:ffff:ffff:ffff
1782034:b1::/322034:b1:ffff:ffff:ffff:ffff:ffff:ffff
1792034:b2::/322034:b2:ffff:ffff:ffff:ffff:ffff:ffff
1802034:b3::/322034:b3:ffff:ffff:ffff:ffff:ffff:ffff
1812034:b4::/322034:b4:ffff:ffff:ffff:ffff:ffff:ffff
1822034:b5::/322034:b5:ffff:ffff:ffff:ffff:ffff:ffff
1832034:b6::/322034:b6:ffff:ffff:ffff:ffff:ffff:ffff
1842034:b7::/322034:b7:ffff:ffff:ffff:ffff:ffff:ffff
1852034:b8::/322034:b8:ffff:ffff:ffff:ffff:ffff:ffff
1862034:b9::/322034:b9:ffff:ffff:ffff:ffff:ffff:ffff
1872034:ba::/322034:ba:ffff:ffff:ffff:ffff:ffff:ffff
1882034:bb::/322034:bb:ffff:ffff:ffff:ffff:ffff:ffff
1892034:bc::/322034:bc:ffff:ffff:ffff:ffff:ffff:ffff
1902034:bd::/322034:bd:ffff:ffff:ffff:ffff:ffff:ffff
1912034:be::/322034:be:ffff:ffff:ffff:ffff:ffff:ffff
1922034:bf::/322034:bf:ffff:ffff:ffff:ffff:ffff:ffff
1932034:c0::/322034:c0:ffff:ffff:ffff:ffff:ffff:ffff
1942034:c1::/322034:c1:ffff:ffff:ffff:ffff:ffff:ffff
1952034:c2::/322034:c2:ffff:ffff:ffff:ffff:ffff:ffff
1962034:c3::/322034:c3:ffff:ffff:ffff:ffff:ffff:ffff
1972034:c4::/322034:c4:ffff:ffff:ffff:ffff:ffff:ffff
1982034:c5::/322034:c5:ffff:ffff:ffff:ffff:ffff:ffff
1992034:c6::/322034:c6:ffff:ffff:ffff:ffff:ffff:ffff
2002034:c7::/322034:c7:ffff:ffff:ffff:ffff:ffff:ffff
2012034:c8::/322034:c8:ffff:ffff:ffff:ffff:ffff:ffff
2022034:c9::/322034:c9:ffff:ffff:ffff:ffff:ffff:ffff
2032034:ca::/322034:ca:ffff:ffff:ffff:ffff:ffff:ffff
2042034:cb::/322034:cb:ffff:ffff:ffff:ffff:ffff:ffff
2052034:cc::/322034:cc:ffff:ffff:ffff:ffff:ffff:ffff
2062034:cd::/322034:cd:ffff:ffff:ffff:ffff:ffff:ffff
2072034:ce::/322034:ce:ffff:ffff:ffff:ffff:ffff:ffff
2082034:cf::/322034:cf:ffff:ffff:ffff:ffff:ffff:ffff
2092034:d0::/322034:d0:ffff:ffff:ffff:ffff:ffff:ffff
2102034:d1::/322034:d1:ffff:ffff:ffff:ffff:ffff:ffff
2112034:d2::/322034:d2:ffff:ffff:ffff:ffff:ffff:ffff
2122034:d3::/322034:d3:ffff:ffff:ffff:ffff:ffff:ffff
2132034:d4::/322034:d4:ffff:ffff:ffff:ffff:ffff:ffff
2142034:d5::/322034:d5:ffff:ffff:ffff:ffff:ffff:ffff
2152034:d6::/322034:d6:ffff:ffff:ffff:ffff:ffff:ffff
2162034:d7::/322034:d7:ffff:ffff:ffff:ffff:ffff:ffff
2172034:d8::/322034:d8:ffff:ffff:ffff:ffff:ffff:ffff
2182034:d9::/322034:d9:ffff:ffff:ffff:ffff:ffff:ffff
2192034:da::/322034:da:ffff:ffff:ffff:ffff:ffff:ffff
2202034:db::/322034:db:ffff:ffff:ffff:ffff:ffff:ffff
2212034:dc::/322034:dc:ffff:ffff:ffff:ffff:ffff:ffff
2222034:dd::/322034:dd:ffff:ffff:ffff:ffff:ffff:ffff
2232034:de::/322034:de:ffff:ffff:ffff:ffff:ffff:ffff
2242034:df::/322034:df:ffff:ffff:ffff:ffff:ffff:ffff
2252034:e0::/322034:e0:ffff:ffff:ffff:ffff:ffff:ffff
2262034:e1::/322034:e1:ffff:ffff:ffff:ffff:ffff:ffff
2272034:e2::/322034:e2:ffff:ffff:ffff:ffff:ffff:ffff
2282034:e3::/322034:e3:ffff:ffff:ffff:ffff:ffff:ffff
2292034:e4::/322034:e4:ffff:ffff:ffff:ffff:ffff:ffff
2302034:e5::/322034:e5:ffff:ffff:ffff:ffff:ffff:ffff
2312034:e6::/322034:e6:ffff:ffff:ffff:ffff:ffff:ffff
2322034:e7::/322034:e7:ffff:ffff:ffff:ffff:ffff:ffff
2332034:e8::/322034:e8:ffff:ffff:ffff:ffff:ffff:ffff
2342034:e9::/322034:e9:ffff:ffff:ffff:ffff:ffff:ffff
2352034:ea::/322034:ea:ffff:ffff:ffff:ffff:ffff:ffff
2362034:eb::/322034:eb:ffff:ffff:ffff:ffff:ffff:ffff
2372034:ec::/322034:ec:ffff:ffff:ffff:ffff:ffff:ffff
2382034:ed::/322034:ed:ffff:ffff:ffff:ffff:ffff:ffff
2392034:ee::/322034:ee:ffff:ffff:ffff:ffff:ffff:ffff
2402034:ef::/322034:ef:ffff:ffff:ffff:ffff:ffff:ffff
2412034:f0::/322034:f0:ffff:ffff:ffff:ffff:ffff:ffff
2422034:f1::/322034:f1:ffff:ffff:ffff:ffff:ffff:ffff
2432034:f2::/322034:f2:ffff:ffff:ffff:ffff:ffff:ffff
2442034:f3::/322034:f3:ffff:ffff:ffff:ffff:ffff:ffff
2452034:f4::/322034:f4:ffff:ffff:ffff:ffff:ffff:ffff
2462034:f5::/322034:f5:ffff:ffff:ffff:ffff:ffff:ffff
2472034:f6::/322034:f6:ffff:ffff:ffff:ffff:ffff:ffff
2482034:f7::/322034:f7:ffff:ffff:ffff:ffff:ffff:ffff
2492034:f8::/322034:f8:ffff:ffff:ffff:ffff:ffff:ffff
2502034:f9::/322034:f9:ffff:ffff:ffff:ffff:ffff:ffff
2512034:fa::/322034:fa:ffff:ffff:ffff:ffff:ffff:ffff
2522034:fb::/322034:fb:ffff:ffff:ffff:ffff:ffff:ffff
2532034:fc::/322034:fc:ffff:ffff:ffff:ffff:ffff:ffff
2542034:fd::/322034:fd:ffff:ffff:ffff:ffff:ffff:ffff
2552034:fe::/322034:fe:ffff:ffff:ffff:ffff:ffff:ffff
2562034:ff::/322034: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.