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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/12
Addresses2^116
/64 networks2^52
Network
2b60::/12
First address
2b60::
Last address
2b6f:ffff:ffff:ffff:ffff:ffff:ffff:ffff
Addresses
83,076,749,736,557,242,056,487,941,267,521,536 (2^116)
/64 networks (LANs)
4,503,599,627,370,496 (2^52)
Full form
2b60:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
6.b.2.ip6.arpa
Split into smaller subnets/20
/13 (2)/14 (4)/15 (8)/16 (16)/20 (256)/24 (4,096)/28 (65,536)

2b60::/12 makes 256 subnets of /20.

Subnets
#SubnetLast address
12b60::/202b60:fff:ffff:ffff:ffff:ffff:ffff:ffff
22b60:1000::/202b60:1fff:ffff:ffff:ffff:ffff:ffff:ffff
32b60:2000::/202b60:2fff:ffff:ffff:ffff:ffff:ffff:ffff
42b60:3000::/202b60:3fff:ffff:ffff:ffff:ffff:ffff:ffff
52b60:4000::/202b60:4fff:ffff:ffff:ffff:ffff:ffff:ffff
62b60:5000::/202b60:5fff:ffff:ffff:ffff:ffff:ffff:ffff
72b60:6000::/202b60:6fff:ffff:ffff:ffff:ffff:ffff:ffff
82b60:7000::/202b60:7fff:ffff:ffff:ffff:ffff:ffff:ffff
92b60:8000::/202b60:8fff:ffff:ffff:ffff:ffff:ffff:ffff
102b60:9000::/202b60:9fff:ffff:ffff:ffff:ffff:ffff:ffff
112b60:a000::/202b60:afff:ffff:ffff:ffff:ffff:ffff:ffff
122b60:b000::/202b60:bfff:ffff:ffff:ffff:ffff:ffff:ffff
132b60:c000::/202b60:cfff:ffff:ffff:ffff:ffff:ffff:ffff
142b60:d000::/202b60:dfff:ffff:ffff:ffff:ffff:ffff:ffff
152b60:e000::/202b60:efff:ffff:ffff:ffff:ffff:ffff:ffff
162b60:f000::/202b60:ffff:ffff:ffff:ffff:ffff:ffff:ffff
172b61::/202b61:fff:ffff:ffff:ffff:ffff:ffff:ffff
182b61:1000::/202b61:1fff:ffff:ffff:ffff:ffff:ffff:ffff
192b61:2000::/202b61:2fff:ffff:ffff:ffff:ffff:ffff:ffff
202b61:3000::/202b61:3fff:ffff:ffff:ffff:ffff:ffff:ffff
212b61:4000::/202b61:4fff:ffff:ffff:ffff:ffff:ffff:ffff
222b61:5000::/202b61:5fff:ffff:ffff:ffff:ffff:ffff:ffff
232b61:6000::/202b61:6fff:ffff:ffff:ffff:ffff:ffff:ffff
242b61:7000::/202b61:7fff:ffff:ffff:ffff:ffff:ffff:ffff
252b61:8000::/202b61:8fff:ffff:ffff:ffff:ffff:ffff:ffff
262b61:9000::/202b61:9fff:ffff:ffff:ffff:ffff:ffff:ffff
272b61:a000::/202b61:afff:ffff:ffff:ffff:ffff:ffff:ffff
282b61:b000::/202b61:bfff:ffff:ffff:ffff:ffff:ffff:ffff
292b61:c000::/202b61:cfff:ffff:ffff:ffff:ffff:ffff:ffff
302b61:d000::/202b61:dfff:ffff:ffff:ffff:ffff:ffff:ffff
312b61:e000::/202b61:efff:ffff:ffff:ffff:ffff:ffff:ffff
322b61:f000::/202b61:ffff:ffff:ffff:ffff:ffff:ffff:ffff
332b62::/202b62:fff:ffff:ffff:ffff:ffff:ffff:ffff
342b62:1000::/202b62:1fff:ffff:ffff:ffff:ffff:ffff:ffff
352b62:2000::/202b62:2fff:ffff:ffff:ffff:ffff:ffff:ffff
362b62:3000::/202b62:3fff:ffff:ffff:ffff:ffff:ffff:ffff
372b62:4000::/202b62:4fff:ffff:ffff:ffff:ffff:ffff:ffff
382b62:5000::/202b62:5fff:ffff:ffff:ffff:ffff:ffff:ffff
392b62:6000::/202b62:6fff:ffff:ffff:ffff:ffff:ffff:ffff
402b62:7000::/202b62:7fff:ffff:ffff:ffff:ffff:ffff:ffff
412b62:8000::/202b62:8fff:ffff:ffff:ffff:ffff:ffff:ffff
422b62:9000::/202b62:9fff:ffff:ffff:ffff:ffff:ffff:ffff
432b62:a000::/202b62:afff:ffff:ffff:ffff:ffff:ffff:ffff
442b62:b000::/202b62:bfff:ffff:ffff:ffff:ffff:ffff:ffff
452b62:c000::/202b62:cfff:ffff:ffff:ffff:ffff:ffff:ffff
462b62:d000::/202b62:dfff:ffff:ffff:ffff:ffff:ffff:ffff
472b62:e000::/202b62:efff:ffff:ffff:ffff:ffff:ffff:ffff
482b62:f000::/202b62:ffff:ffff:ffff:ffff:ffff:ffff:ffff
492b63::/202b63:fff:ffff:ffff:ffff:ffff:ffff:ffff
502b63:1000::/202b63:1fff:ffff:ffff:ffff:ffff:ffff:ffff
512b63:2000::/202b63:2fff:ffff:ffff:ffff:ffff:ffff:ffff
522b63:3000::/202b63:3fff:ffff:ffff:ffff:ffff:ffff:ffff
532b63:4000::/202b63:4fff:ffff:ffff:ffff:ffff:ffff:ffff
542b63:5000::/202b63:5fff:ffff:ffff:ffff:ffff:ffff:ffff
552b63:6000::/202b63:6fff:ffff:ffff:ffff:ffff:ffff:ffff
562b63:7000::/202b63:7fff:ffff:ffff:ffff:ffff:ffff:ffff
572b63:8000::/202b63:8fff:ffff:ffff:ffff:ffff:ffff:ffff
582b63:9000::/202b63:9fff:ffff:ffff:ffff:ffff:ffff:ffff
592b63:a000::/202b63:afff:ffff:ffff:ffff:ffff:ffff:ffff
602b63:b000::/202b63:bfff:ffff:ffff:ffff:ffff:ffff:ffff
612b63:c000::/202b63:cfff:ffff:ffff:ffff:ffff:ffff:ffff
622b63:d000::/202b63:dfff:ffff:ffff:ffff:ffff:ffff:ffff
632b63:e000::/202b63:efff:ffff:ffff:ffff:ffff:ffff:ffff
642b63:f000::/202b63:ffff:ffff:ffff:ffff:ffff:ffff:ffff
652b64::/202b64:fff:ffff:ffff:ffff:ffff:ffff:ffff
662b64:1000::/202b64:1fff:ffff:ffff:ffff:ffff:ffff:ffff
672b64:2000::/202b64:2fff:ffff:ffff:ffff:ffff:ffff:ffff
682b64:3000::/202b64:3fff:ffff:ffff:ffff:ffff:ffff:ffff
692b64:4000::/202b64:4fff:ffff:ffff:ffff:ffff:ffff:ffff
702b64:5000::/202b64:5fff:ffff:ffff:ffff:ffff:ffff:ffff
712b64:6000::/202b64:6fff:ffff:ffff:ffff:ffff:ffff:ffff
722b64:7000::/202b64:7fff:ffff:ffff:ffff:ffff:ffff:ffff
732b64:8000::/202b64:8fff:ffff:ffff:ffff:ffff:ffff:ffff
742b64:9000::/202b64:9fff:ffff:ffff:ffff:ffff:ffff:ffff
752b64:a000::/202b64:afff:ffff:ffff:ffff:ffff:ffff:ffff
762b64:b000::/202b64:bfff:ffff:ffff:ffff:ffff:ffff:ffff
772b64:c000::/202b64:cfff:ffff:ffff:ffff:ffff:ffff:ffff
782b64:d000::/202b64:dfff:ffff:ffff:ffff:ffff:ffff:ffff
792b64:e000::/202b64:efff:ffff:ffff:ffff:ffff:ffff:ffff
802b64:f000::/202b64:ffff:ffff:ffff:ffff:ffff:ffff:ffff
812b65::/202b65:fff:ffff:ffff:ffff:ffff:ffff:ffff
822b65:1000::/202b65:1fff:ffff:ffff:ffff:ffff:ffff:ffff
832b65:2000::/202b65:2fff:ffff:ffff:ffff:ffff:ffff:ffff
842b65:3000::/202b65:3fff:ffff:ffff:ffff:ffff:ffff:ffff
852b65:4000::/202b65:4fff:ffff:ffff:ffff:ffff:ffff:ffff
862b65:5000::/202b65:5fff:ffff:ffff:ffff:ffff:ffff:ffff
872b65:6000::/202b65:6fff:ffff:ffff:ffff:ffff:ffff:ffff
882b65:7000::/202b65:7fff:ffff:ffff:ffff:ffff:ffff:ffff
892b65:8000::/202b65:8fff:ffff:ffff:ffff:ffff:ffff:ffff
902b65:9000::/202b65:9fff:ffff:ffff:ffff:ffff:ffff:ffff
912b65:a000::/202b65:afff:ffff:ffff:ffff:ffff:ffff:ffff
922b65:b000::/202b65:bfff:ffff:ffff:ffff:ffff:ffff:ffff
932b65:c000::/202b65:cfff:ffff:ffff:ffff:ffff:ffff:ffff
942b65:d000::/202b65:dfff:ffff:ffff:ffff:ffff:ffff:ffff
952b65:e000::/202b65:efff:ffff:ffff:ffff:ffff:ffff:ffff
962b65:f000::/202b65:ffff:ffff:ffff:ffff:ffff:ffff:ffff
972b66::/202b66:fff:ffff:ffff:ffff:ffff:ffff:ffff
982b66:1000::/202b66:1fff:ffff:ffff:ffff:ffff:ffff:ffff
992b66:2000::/202b66:2fff:ffff:ffff:ffff:ffff:ffff:ffff
1002b66:3000::/202b66:3fff:ffff:ffff:ffff:ffff:ffff:ffff
1012b66:4000::/202b66:4fff:ffff:ffff:ffff:ffff:ffff:ffff
1022b66:5000::/202b66:5fff:ffff:ffff:ffff:ffff:ffff:ffff
1032b66:6000::/202b66:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1042b66:7000::/202b66:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1052b66:8000::/202b66:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1062b66:9000::/202b66:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1072b66:a000::/202b66:afff:ffff:ffff:ffff:ffff:ffff:ffff
1082b66:b000::/202b66:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1092b66:c000::/202b66:cfff:ffff:ffff:ffff:ffff:ffff:ffff
1102b66:d000::/202b66:dfff:ffff:ffff:ffff:ffff:ffff:ffff
1112b66:e000::/202b66:efff:ffff:ffff:ffff:ffff:ffff:ffff
1122b66:f000::/202b66:ffff:ffff:ffff:ffff:ffff:ffff:ffff
1132b67::/202b67:fff:ffff:ffff:ffff:ffff:ffff:ffff
1142b67:1000::/202b67:1fff:ffff:ffff:ffff:ffff:ffff:ffff
1152b67:2000::/202b67:2fff:ffff:ffff:ffff:ffff:ffff:ffff
1162b67:3000::/202b67:3fff:ffff:ffff:ffff:ffff:ffff:ffff
1172b67:4000::/202b67:4fff:ffff:ffff:ffff:ffff:ffff:ffff
1182b67:5000::/202b67:5fff:ffff:ffff:ffff:ffff:ffff:ffff
1192b67:6000::/202b67:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1202b67:7000::/202b67:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1212b67:8000::/202b67:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1222b67:9000::/202b67:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1232b67:a000::/202b67:afff:ffff:ffff:ffff:ffff:ffff:ffff
1242b67:b000::/202b67:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1252b67:c000::/202b67:cfff:ffff:ffff:ffff:ffff:ffff:ffff
1262b67:d000::/202b67:dfff:ffff:ffff:ffff:ffff:ffff:ffff
1272b67:e000::/202b67:efff:ffff:ffff:ffff:ffff:ffff:ffff
1282b67:f000::/202b67:ffff:ffff:ffff:ffff:ffff:ffff:ffff
1292b68::/202b68:fff:ffff:ffff:ffff:ffff:ffff:ffff
1302b68:1000::/202b68:1fff:ffff:ffff:ffff:ffff:ffff:ffff
1312b68:2000::/202b68:2fff:ffff:ffff:ffff:ffff:ffff:ffff
1322b68:3000::/202b68:3fff:ffff:ffff:ffff:ffff:ffff:ffff
1332b68:4000::/202b68:4fff:ffff:ffff:ffff:ffff:ffff:ffff
1342b68:5000::/202b68:5fff:ffff:ffff:ffff:ffff:ffff:ffff
1352b68:6000::/202b68:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1362b68:7000::/202b68:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1372b68:8000::/202b68:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1382b68:9000::/202b68:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1392b68:a000::/202b68:afff:ffff:ffff:ffff:ffff:ffff:ffff
1402b68:b000::/202b68:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1412b68:c000::/202b68:cfff:ffff:ffff:ffff:ffff:ffff:ffff
1422b68:d000::/202b68:dfff:ffff:ffff:ffff:ffff:ffff:ffff
1432b68:e000::/202b68:efff:ffff:ffff:ffff:ffff:ffff:ffff
1442b68:f000::/202b68:ffff:ffff:ffff:ffff:ffff:ffff:ffff
1452b69::/202b69:fff:ffff:ffff:ffff:ffff:ffff:ffff
1462b69:1000::/202b69:1fff:ffff:ffff:ffff:ffff:ffff:ffff
1472b69:2000::/202b69:2fff:ffff:ffff:ffff:ffff:ffff:ffff
1482b69:3000::/202b69:3fff:ffff:ffff:ffff:ffff:ffff:ffff
1492b69:4000::/202b69:4fff:ffff:ffff:ffff:ffff:ffff:ffff
1502b69:5000::/202b69:5fff:ffff:ffff:ffff:ffff:ffff:ffff
1512b69:6000::/202b69:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1522b69:7000::/202b69:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1532b69:8000::/202b69:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1542b69:9000::/202b69:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1552b69:a000::/202b69:afff:ffff:ffff:ffff:ffff:ffff:ffff
1562b69:b000::/202b69:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1572b69:c000::/202b69:cfff:ffff:ffff:ffff:ffff:ffff:ffff
1582b69:d000::/202b69:dfff:ffff:ffff:ffff:ffff:ffff:ffff
1592b69:e000::/202b69:efff:ffff:ffff:ffff:ffff:ffff:ffff
1602b69:f000::/202b69:ffff:ffff:ffff:ffff:ffff:ffff:ffff
1612b6a::/202b6a:fff:ffff:ffff:ffff:ffff:ffff:ffff
1622b6a:1000::/202b6a:1fff:ffff:ffff:ffff:ffff:ffff:ffff
1632b6a:2000::/202b6a:2fff:ffff:ffff:ffff:ffff:ffff:ffff
1642b6a:3000::/202b6a:3fff:ffff:ffff:ffff:ffff:ffff:ffff
1652b6a:4000::/202b6a:4fff:ffff:ffff:ffff:ffff:ffff:ffff
1662b6a:5000::/202b6a:5fff:ffff:ffff:ffff:ffff:ffff:ffff
1672b6a:6000::/202b6a:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1682b6a:7000::/202b6a:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1692b6a:8000::/202b6a:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1702b6a:9000::/202b6a:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1712b6a:a000::/202b6a:afff:ffff:ffff:ffff:ffff:ffff:ffff
1722b6a:b000::/202b6a:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1732b6a:c000::/202b6a:cfff:ffff:ffff:ffff:ffff:ffff:ffff
1742b6a:d000::/202b6a:dfff:ffff:ffff:ffff:ffff:ffff:ffff
1752b6a:e000::/202b6a:efff:ffff:ffff:ffff:ffff:ffff:ffff
1762b6a:f000::/202b6a:ffff:ffff:ffff:ffff:ffff:ffff:ffff
1772b6b::/202b6b:fff:ffff:ffff:ffff:ffff:ffff:ffff
1782b6b:1000::/202b6b:1fff:ffff:ffff:ffff:ffff:ffff:ffff
1792b6b:2000::/202b6b:2fff:ffff:ffff:ffff:ffff:ffff:ffff
1802b6b:3000::/202b6b:3fff:ffff:ffff:ffff:ffff:ffff:ffff
1812b6b:4000::/202b6b:4fff:ffff:ffff:ffff:ffff:ffff:ffff
1822b6b:5000::/202b6b:5fff:ffff:ffff:ffff:ffff:ffff:ffff
1832b6b:6000::/202b6b:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1842b6b:7000::/202b6b:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1852b6b:8000::/202b6b:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1862b6b:9000::/202b6b:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1872b6b:a000::/202b6b:afff:ffff:ffff:ffff:ffff:ffff:ffff
1882b6b:b000::/202b6b:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1892b6b:c000::/202b6b:cfff:ffff:ffff:ffff:ffff:ffff:ffff
1902b6b:d000::/202b6b:dfff:ffff:ffff:ffff:ffff:ffff:ffff
1912b6b:e000::/202b6b:efff:ffff:ffff:ffff:ffff:ffff:ffff
1922b6b:f000::/202b6b:ffff:ffff:ffff:ffff:ffff:ffff:ffff
1932b6c::/202b6c:fff:ffff:ffff:ffff:ffff:ffff:ffff
1942b6c:1000::/202b6c:1fff:ffff:ffff:ffff:ffff:ffff:ffff
1952b6c:2000::/202b6c:2fff:ffff:ffff:ffff:ffff:ffff:ffff
1962b6c:3000::/202b6c:3fff:ffff:ffff:ffff:ffff:ffff:ffff
1972b6c:4000::/202b6c:4fff:ffff:ffff:ffff:ffff:ffff:ffff
1982b6c:5000::/202b6c:5fff:ffff:ffff:ffff:ffff:ffff:ffff
1992b6c:6000::/202b6c:6fff:ffff:ffff:ffff:ffff:ffff:ffff
2002b6c:7000::/202b6c:7fff:ffff:ffff:ffff:ffff:ffff:ffff
2012b6c:8000::/202b6c:8fff:ffff:ffff:ffff:ffff:ffff:ffff
2022b6c:9000::/202b6c:9fff:ffff:ffff:ffff:ffff:ffff:ffff
2032b6c:a000::/202b6c:afff:ffff:ffff:ffff:ffff:ffff:ffff
2042b6c:b000::/202b6c:bfff:ffff:ffff:ffff:ffff:ffff:ffff
2052b6c:c000::/202b6c:cfff:ffff:ffff:ffff:ffff:ffff:ffff
2062b6c:d000::/202b6c:dfff:ffff:ffff:ffff:ffff:ffff:ffff
2072b6c:e000::/202b6c:efff:ffff:ffff:ffff:ffff:ffff:ffff
2082b6c:f000::/202b6c:ffff:ffff:ffff:ffff:ffff:ffff:ffff
2092b6d::/202b6d:fff:ffff:ffff:ffff:ffff:ffff:ffff
2102b6d:1000::/202b6d:1fff:ffff:ffff:ffff:ffff:ffff:ffff
2112b6d:2000::/202b6d:2fff:ffff:ffff:ffff:ffff:ffff:ffff
2122b6d:3000::/202b6d:3fff:ffff:ffff:ffff:ffff:ffff:ffff
2132b6d:4000::/202b6d:4fff:ffff:ffff:ffff:ffff:ffff:ffff
2142b6d:5000::/202b6d:5fff:ffff:ffff:ffff:ffff:ffff:ffff
2152b6d:6000::/202b6d:6fff:ffff:ffff:ffff:ffff:ffff:ffff
2162b6d:7000::/202b6d:7fff:ffff:ffff:ffff:ffff:ffff:ffff
2172b6d:8000::/202b6d:8fff:ffff:ffff:ffff:ffff:ffff:ffff
2182b6d:9000::/202b6d:9fff:ffff:ffff:ffff:ffff:ffff:ffff
2192b6d:a000::/202b6d:afff:ffff:ffff:ffff:ffff:ffff:ffff
2202b6d:b000::/202b6d:bfff:ffff:ffff:ffff:ffff:ffff:ffff
2212b6d:c000::/202b6d:cfff:ffff:ffff:ffff:ffff:ffff:ffff
2222b6d:d000::/202b6d:dfff:ffff:ffff:ffff:ffff:ffff:ffff
2232b6d:e000::/202b6d:efff:ffff:ffff:ffff:ffff:ffff:ffff
2242b6d:f000::/202b6d:ffff:ffff:ffff:ffff:ffff:ffff:ffff
2252b6e::/202b6e:fff:ffff:ffff:ffff:ffff:ffff:ffff
2262b6e:1000::/202b6e:1fff:ffff:ffff:ffff:ffff:ffff:ffff
2272b6e:2000::/202b6e:2fff:ffff:ffff:ffff:ffff:ffff:ffff
2282b6e:3000::/202b6e:3fff:ffff:ffff:ffff:ffff:ffff:ffff
2292b6e:4000::/202b6e:4fff:ffff:ffff:ffff:ffff:ffff:ffff
2302b6e:5000::/202b6e:5fff:ffff:ffff:ffff:ffff:ffff:ffff
2312b6e:6000::/202b6e:6fff:ffff:ffff:ffff:ffff:ffff:ffff
2322b6e:7000::/202b6e:7fff:ffff:ffff:ffff:ffff:ffff:ffff
2332b6e:8000::/202b6e:8fff:ffff:ffff:ffff:ffff:ffff:ffff
2342b6e:9000::/202b6e:9fff:ffff:ffff:ffff:ffff:ffff:ffff
2352b6e:a000::/202b6e:afff:ffff:ffff:ffff:ffff:ffff:ffff
2362b6e:b000::/202b6e:bfff:ffff:ffff:ffff:ffff:ffff:ffff
2372b6e:c000::/202b6e:cfff:ffff:ffff:ffff:ffff:ffff:ffff
2382b6e:d000::/202b6e:dfff:ffff:ffff:ffff:ffff:ffff:ffff
2392b6e:e000::/202b6e:efff:ffff:ffff:ffff:ffff:ffff:ffff
2402b6e:f000::/202b6e:ffff:ffff:ffff:ffff:ffff:ffff:ffff
2412b6f::/202b6f:fff:ffff:ffff:ffff:ffff:ffff:ffff
2422b6f:1000::/202b6f:1fff:ffff:ffff:ffff:ffff:ffff:ffff
2432b6f:2000::/202b6f:2fff:ffff:ffff:ffff:ffff:ffff:ffff
2442b6f:3000::/202b6f:3fff:ffff:ffff:ffff:ffff:ffff:ffff
2452b6f:4000::/202b6f:4fff:ffff:ffff:ffff:ffff:ffff:ffff
2462b6f:5000::/202b6f:5fff:ffff:ffff:ffff:ffff:ffff:ffff
2472b6f:6000::/202b6f:6fff:ffff:ffff:ffff:ffff:ffff:ffff
2482b6f:7000::/202b6f:7fff:ffff:ffff:ffff:ffff:ffff:ffff
2492b6f:8000::/202b6f:8fff:ffff:ffff:ffff:ffff:ffff:ffff
2502b6f:9000::/202b6f:9fff:ffff:ffff:ffff:ffff:ffff:ffff
2512b6f:a000::/202b6f:afff:ffff:ffff:ffff:ffff:ffff:ffff
2522b6f:b000::/202b6f:bfff:ffff:ffff:ffff:ffff:ffff:ffff
2532b6f:c000::/202b6f:cfff:ffff:ffff:ffff:ffff:ffff:ffff
2542b6f:d000::/202b6f:dfff:ffff:ffff:ffff:ffff:ffff:ffff
2552b6f:e000::/202b6f:efff:ffff:ffff:ffff:ffff:ffff:ffff
2562b6f:f000::/202b6f:ffff: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.