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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
2920::/12
First address
2920::
Last address
292f: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
2920:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
2.9.2.ip6.arpa
Split into smaller subnets/28
/13 (2)/14 (4)/15 (8)/16 (16)/20 (256)/24 (4,096)/28 (65,536)

2920::/12 makes 65,536 subnets of /28; the first 256 are listed.

Subnets
#SubnetLast address
12920::/282920:f:ffff:ffff:ffff:ffff:ffff:ffff
22920:10::/282920:1f:ffff:ffff:ffff:ffff:ffff:ffff
32920:20::/282920:2f:ffff:ffff:ffff:ffff:ffff:ffff
42920:30::/282920:3f:ffff:ffff:ffff:ffff:ffff:ffff
52920:40::/282920:4f:ffff:ffff:ffff:ffff:ffff:ffff
62920:50::/282920:5f:ffff:ffff:ffff:ffff:ffff:ffff
72920:60::/282920:6f:ffff:ffff:ffff:ffff:ffff:ffff
82920:70::/282920:7f:ffff:ffff:ffff:ffff:ffff:ffff
92920:80::/282920:8f:ffff:ffff:ffff:ffff:ffff:ffff
102920:90::/282920:9f:ffff:ffff:ffff:ffff:ffff:ffff
112920:a0::/282920:af:ffff:ffff:ffff:ffff:ffff:ffff
122920:b0::/282920:bf:ffff:ffff:ffff:ffff:ffff:ffff
132920:c0::/282920:cf:ffff:ffff:ffff:ffff:ffff:ffff
142920:d0::/282920:df:ffff:ffff:ffff:ffff:ffff:ffff
152920:e0::/282920:ef:ffff:ffff:ffff:ffff:ffff:ffff
162920:f0::/282920:ff:ffff:ffff:ffff:ffff:ffff:ffff
172920:100::/282920:10f:ffff:ffff:ffff:ffff:ffff:ffff
182920:110::/282920:11f:ffff:ffff:ffff:ffff:ffff:ffff
192920:120::/282920:12f:ffff:ffff:ffff:ffff:ffff:ffff
202920:130::/282920:13f:ffff:ffff:ffff:ffff:ffff:ffff
212920:140::/282920:14f:ffff:ffff:ffff:ffff:ffff:ffff
222920:150::/282920:15f:ffff:ffff:ffff:ffff:ffff:ffff
232920:160::/282920:16f:ffff:ffff:ffff:ffff:ffff:ffff
242920:170::/282920:17f:ffff:ffff:ffff:ffff:ffff:ffff
252920:180::/282920:18f:ffff:ffff:ffff:ffff:ffff:ffff
262920:190::/282920:19f:ffff:ffff:ffff:ffff:ffff:ffff
272920:1a0::/282920:1af:ffff:ffff:ffff:ffff:ffff:ffff
282920:1b0::/282920:1bf:ffff:ffff:ffff:ffff:ffff:ffff
292920:1c0::/282920:1cf:ffff:ffff:ffff:ffff:ffff:ffff
302920:1d0::/282920:1df:ffff:ffff:ffff:ffff:ffff:ffff
312920:1e0::/282920:1ef:ffff:ffff:ffff:ffff:ffff:ffff
322920:1f0::/282920:1ff:ffff:ffff:ffff:ffff:ffff:ffff
332920:200::/282920:20f:ffff:ffff:ffff:ffff:ffff:ffff
342920:210::/282920:21f:ffff:ffff:ffff:ffff:ffff:ffff
352920:220::/282920:22f:ffff:ffff:ffff:ffff:ffff:ffff
362920:230::/282920:23f:ffff:ffff:ffff:ffff:ffff:ffff
372920:240::/282920:24f:ffff:ffff:ffff:ffff:ffff:ffff
382920:250::/282920:25f:ffff:ffff:ffff:ffff:ffff:ffff
392920:260::/282920:26f:ffff:ffff:ffff:ffff:ffff:ffff
402920:270::/282920:27f:ffff:ffff:ffff:ffff:ffff:ffff
412920:280::/282920:28f:ffff:ffff:ffff:ffff:ffff:ffff
422920:290::/282920:29f:ffff:ffff:ffff:ffff:ffff:ffff
432920:2a0::/282920:2af:ffff:ffff:ffff:ffff:ffff:ffff
442920:2b0::/282920:2bf:ffff:ffff:ffff:ffff:ffff:ffff
452920:2c0::/282920:2cf:ffff:ffff:ffff:ffff:ffff:ffff
462920:2d0::/282920:2df:ffff:ffff:ffff:ffff:ffff:ffff
472920:2e0::/282920:2ef:ffff:ffff:ffff:ffff:ffff:ffff
482920:2f0::/282920:2ff:ffff:ffff:ffff:ffff:ffff:ffff
492920:300::/282920:30f:ffff:ffff:ffff:ffff:ffff:ffff
502920:310::/282920:31f:ffff:ffff:ffff:ffff:ffff:ffff
512920:320::/282920:32f:ffff:ffff:ffff:ffff:ffff:ffff
522920:330::/282920:33f:ffff:ffff:ffff:ffff:ffff:ffff
532920:340::/282920:34f:ffff:ffff:ffff:ffff:ffff:ffff
542920:350::/282920:35f:ffff:ffff:ffff:ffff:ffff:ffff
552920:360::/282920:36f:ffff:ffff:ffff:ffff:ffff:ffff
562920:370::/282920:37f:ffff:ffff:ffff:ffff:ffff:ffff
572920:380::/282920:38f:ffff:ffff:ffff:ffff:ffff:ffff
582920:390::/282920:39f:ffff:ffff:ffff:ffff:ffff:ffff
592920:3a0::/282920:3af:ffff:ffff:ffff:ffff:ffff:ffff
602920:3b0::/282920:3bf:ffff:ffff:ffff:ffff:ffff:ffff
612920:3c0::/282920:3cf:ffff:ffff:ffff:ffff:ffff:ffff
622920:3d0::/282920:3df:ffff:ffff:ffff:ffff:ffff:ffff
632920:3e0::/282920:3ef:ffff:ffff:ffff:ffff:ffff:ffff
642920:3f0::/282920:3ff:ffff:ffff:ffff:ffff:ffff:ffff
652920:400::/282920:40f:ffff:ffff:ffff:ffff:ffff:ffff
662920:410::/282920:41f:ffff:ffff:ffff:ffff:ffff:ffff
672920:420::/282920:42f:ffff:ffff:ffff:ffff:ffff:ffff
682920:430::/282920:43f:ffff:ffff:ffff:ffff:ffff:ffff
692920:440::/282920:44f:ffff:ffff:ffff:ffff:ffff:ffff
702920:450::/282920:45f:ffff:ffff:ffff:ffff:ffff:ffff
712920:460::/282920:46f:ffff:ffff:ffff:ffff:ffff:ffff
722920:470::/282920:47f:ffff:ffff:ffff:ffff:ffff:ffff
732920:480::/282920:48f:ffff:ffff:ffff:ffff:ffff:ffff
742920:490::/282920:49f:ffff:ffff:ffff:ffff:ffff:ffff
752920:4a0::/282920:4af:ffff:ffff:ffff:ffff:ffff:ffff
762920:4b0::/282920:4bf:ffff:ffff:ffff:ffff:ffff:ffff
772920:4c0::/282920:4cf:ffff:ffff:ffff:ffff:ffff:ffff
782920:4d0::/282920:4df:ffff:ffff:ffff:ffff:ffff:ffff
792920:4e0::/282920:4ef:ffff:ffff:ffff:ffff:ffff:ffff
802920:4f0::/282920:4ff:ffff:ffff:ffff:ffff:ffff:ffff
812920:500::/282920:50f:ffff:ffff:ffff:ffff:ffff:ffff
822920:510::/282920:51f:ffff:ffff:ffff:ffff:ffff:ffff
832920:520::/282920:52f:ffff:ffff:ffff:ffff:ffff:ffff
842920:530::/282920:53f:ffff:ffff:ffff:ffff:ffff:ffff
852920:540::/282920:54f:ffff:ffff:ffff:ffff:ffff:ffff
862920:550::/282920:55f:ffff:ffff:ffff:ffff:ffff:ffff
872920:560::/282920:56f:ffff:ffff:ffff:ffff:ffff:ffff
882920:570::/282920:57f:ffff:ffff:ffff:ffff:ffff:ffff
892920:580::/282920:58f:ffff:ffff:ffff:ffff:ffff:ffff
902920:590::/282920:59f:ffff:ffff:ffff:ffff:ffff:ffff
912920:5a0::/282920:5af:ffff:ffff:ffff:ffff:ffff:ffff
922920:5b0::/282920:5bf:ffff:ffff:ffff:ffff:ffff:ffff
932920:5c0::/282920:5cf:ffff:ffff:ffff:ffff:ffff:ffff
942920:5d0::/282920:5df:ffff:ffff:ffff:ffff:ffff:ffff
952920:5e0::/282920:5ef:ffff:ffff:ffff:ffff:ffff:ffff
962920:5f0::/282920:5ff:ffff:ffff:ffff:ffff:ffff:ffff
972920:600::/282920:60f:ffff:ffff:ffff:ffff:ffff:ffff
982920:610::/282920:61f:ffff:ffff:ffff:ffff:ffff:ffff
992920:620::/282920:62f:ffff:ffff:ffff:ffff:ffff:ffff
1002920:630::/282920:63f:ffff:ffff:ffff:ffff:ffff:ffff
1012920:640::/282920:64f:ffff:ffff:ffff:ffff:ffff:ffff
1022920:650::/282920:65f:ffff:ffff:ffff:ffff:ffff:ffff
1032920:660::/282920:66f:ffff:ffff:ffff:ffff:ffff:ffff
1042920:670::/282920:67f:ffff:ffff:ffff:ffff:ffff:ffff
1052920:680::/282920:68f:ffff:ffff:ffff:ffff:ffff:ffff
1062920:690::/282920:69f:ffff:ffff:ffff:ffff:ffff:ffff
1072920:6a0::/282920:6af:ffff:ffff:ffff:ffff:ffff:ffff
1082920:6b0::/282920:6bf:ffff:ffff:ffff:ffff:ffff:ffff
1092920:6c0::/282920:6cf:ffff:ffff:ffff:ffff:ffff:ffff
1102920:6d0::/282920:6df:ffff:ffff:ffff:ffff:ffff:ffff
1112920:6e0::/282920:6ef:ffff:ffff:ffff:ffff:ffff:ffff
1122920:6f0::/282920:6ff:ffff:ffff:ffff:ffff:ffff:ffff
1132920:700::/282920:70f:ffff:ffff:ffff:ffff:ffff:ffff
1142920:710::/282920:71f:ffff:ffff:ffff:ffff:ffff:ffff
1152920:720::/282920:72f:ffff:ffff:ffff:ffff:ffff:ffff
1162920:730::/282920:73f:ffff:ffff:ffff:ffff:ffff:ffff
1172920:740::/282920:74f:ffff:ffff:ffff:ffff:ffff:ffff
1182920:750::/282920:75f:ffff:ffff:ffff:ffff:ffff:ffff
1192920:760::/282920:76f:ffff:ffff:ffff:ffff:ffff:ffff
1202920:770::/282920:77f:ffff:ffff:ffff:ffff:ffff:ffff
1212920:780::/282920:78f:ffff:ffff:ffff:ffff:ffff:ffff
1222920:790::/282920:79f:ffff:ffff:ffff:ffff:ffff:ffff
1232920:7a0::/282920:7af:ffff:ffff:ffff:ffff:ffff:ffff
1242920:7b0::/282920:7bf:ffff:ffff:ffff:ffff:ffff:ffff
1252920:7c0::/282920:7cf:ffff:ffff:ffff:ffff:ffff:ffff
1262920:7d0::/282920:7df:ffff:ffff:ffff:ffff:ffff:ffff
1272920:7e0::/282920:7ef:ffff:ffff:ffff:ffff:ffff:ffff
1282920:7f0::/282920:7ff:ffff:ffff:ffff:ffff:ffff:ffff
1292920:800::/282920:80f:ffff:ffff:ffff:ffff:ffff:ffff
1302920:810::/282920:81f:ffff:ffff:ffff:ffff:ffff:ffff
1312920:820::/282920:82f:ffff:ffff:ffff:ffff:ffff:ffff
1322920:830::/282920:83f:ffff:ffff:ffff:ffff:ffff:ffff
1332920:840::/282920:84f:ffff:ffff:ffff:ffff:ffff:ffff
1342920:850::/282920:85f:ffff:ffff:ffff:ffff:ffff:ffff
1352920:860::/282920:86f:ffff:ffff:ffff:ffff:ffff:ffff
1362920:870::/282920:87f:ffff:ffff:ffff:ffff:ffff:ffff
1372920:880::/282920:88f:ffff:ffff:ffff:ffff:ffff:ffff
1382920:890::/282920:89f:ffff:ffff:ffff:ffff:ffff:ffff
1392920:8a0::/282920:8af:ffff:ffff:ffff:ffff:ffff:ffff
1402920:8b0::/282920:8bf:ffff:ffff:ffff:ffff:ffff:ffff
1412920:8c0::/282920:8cf:ffff:ffff:ffff:ffff:ffff:ffff
1422920:8d0::/282920:8df:ffff:ffff:ffff:ffff:ffff:ffff
1432920:8e0::/282920:8ef:ffff:ffff:ffff:ffff:ffff:ffff
1442920:8f0::/282920:8ff:ffff:ffff:ffff:ffff:ffff:ffff
1452920:900::/282920:90f:ffff:ffff:ffff:ffff:ffff:ffff
1462920:910::/282920:91f:ffff:ffff:ffff:ffff:ffff:ffff
1472920:920::/282920:92f:ffff:ffff:ffff:ffff:ffff:ffff
1482920:930::/282920:93f:ffff:ffff:ffff:ffff:ffff:ffff
1492920:940::/282920:94f:ffff:ffff:ffff:ffff:ffff:ffff
1502920:950::/282920:95f:ffff:ffff:ffff:ffff:ffff:ffff
1512920:960::/282920:96f:ffff:ffff:ffff:ffff:ffff:ffff
1522920:970::/282920:97f:ffff:ffff:ffff:ffff:ffff:ffff
1532920:980::/282920:98f:ffff:ffff:ffff:ffff:ffff:ffff
1542920:990::/282920:99f:ffff:ffff:ffff:ffff:ffff:ffff
1552920:9a0::/282920:9af:ffff:ffff:ffff:ffff:ffff:ffff
1562920:9b0::/282920:9bf:ffff:ffff:ffff:ffff:ffff:ffff
1572920:9c0::/282920:9cf:ffff:ffff:ffff:ffff:ffff:ffff
1582920:9d0::/282920:9df:ffff:ffff:ffff:ffff:ffff:ffff
1592920:9e0::/282920:9ef:ffff:ffff:ffff:ffff:ffff:ffff
1602920:9f0::/282920:9ff:ffff:ffff:ffff:ffff:ffff:ffff
1612920:a00::/282920:a0f:ffff:ffff:ffff:ffff:ffff:ffff
1622920:a10::/282920:a1f:ffff:ffff:ffff:ffff:ffff:ffff
1632920:a20::/282920:a2f:ffff:ffff:ffff:ffff:ffff:ffff
1642920:a30::/282920:a3f:ffff:ffff:ffff:ffff:ffff:ffff
1652920:a40::/282920:a4f:ffff:ffff:ffff:ffff:ffff:ffff
1662920:a50::/282920:a5f:ffff:ffff:ffff:ffff:ffff:ffff
1672920:a60::/282920:a6f:ffff:ffff:ffff:ffff:ffff:ffff
1682920:a70::/282920:a7f:ffff:ffff:ffff:ffff:ffff:ffff
1692920:a80::/282920:a8f:ffff:ffff:ffff:ffff:ffff:ffff
1702920:a90::/282920:a9f:ffff:ffff:ffff:ffff:ffff:ffff
1712920:aa0::/282920:aaf:ffff:ffff:ffff:ffff:ffff:ffff
1722920:ab0::/282920:abf:ffff:ffff:ffff:ffff:ffff:ffff
1732920:ac0::/282920:acf:ffff:ffff:ffff:ffff:ffff:ffff
1742920:ad0::/282920:adf:ffff:ffff:ffff:ffff:ffff:ffff
1752920:ae0::/282920:aef:ffff:ffff:ffff:ffff:ffff:ffff
1762920:af0::/282920:aff:ffff:ffff:ffff:ffff:ffff:ffff
1772920:b00::/282920:b0f:ffff:ffff:ffff:ffff:ffff:ffff
1782920:b10::/282920:b1f:ffff:ffff:ffff:ffff:ffff:ffff
1792920:b20::/282920:b2f:ffff:ffff:ffff:ffff:ffff:ffff
1802920:b30::/282920:b3f:ffff:ffff:ffff:ffff:ffff:ffff
1812920:b40::/282920:b4f:ffff:ffff:ffff:ffff:ffff:ffff
1822920:b50::/282920:b5f:ffff:ffff:ffff:ffff:ffff:ffff
1832920:b60::/282920:b6f:ffff:ffff:ffff:ffff:ffff:ffff
1842920:b70::/282920:b7f:ffff:ffff:ffff:ffff:ffff:ffff
1852920:b80::/282920:b8f:ffff:ffff:ffff:ffff:ffff:ffff
1862920:b90::/282920:b9f:ffff:ffff:ffff:ffff:ffff:ffff
1872920:ba0::/282920:baf:ffff:ffff:ffff:ffff:ffff:ffff
1882920:bb0::/282920:bbf:ffff:ffff:ffff:ffff:ffff:ffff
1892920:bc0::/282920:bcf:ffff:ffff:ffff:ffff:ffff:ffff
1902920:bd0::/282920:bdf:ffff:ffff:ffff:ffff:ffff:ffff
1912920:be0::/282920:bef:ffff:ffff:ffff:ffff:ffff:ffff
1922920:bf0::/282920:bff:ffff:ffff:ffff:ffff:ffff:ffff
1932920:c00::/282920:c0f:ffff:ffff:ffff:ffff:ffff:ffff
1942920:c10::/282920:c1f:ffff:ffff:ffff:ffff:ffff:ffff
1952920:c20::/282920:c2f:ffff:ffff:ffff:ffff:ffff:ffff
1962920:c30::/282920:c3f:ffff:ffff:ffff:ffff:ffff:ffff
1972920:c40::/282920:c4f:ffff:ffff:ffff:ffff:ffff:ffff
1982920:c50::/282920:c5f:ffff:ffff:ffff:ffff:ffff:ffff
1992920:c60::/282920:c6f:ffff:ffff:ffff:ffff:ffff:ffff
2002920:c70::/282920:c7f:ffff:ffff:ffff:ffff:ffff:ffff
2012920:c80::/282920:c8f:ffff:ffff:ffff:ffff:ffff:ffff
2022920:c90::/282920:c9f:ffff:ffff:ffff:ffff:ffff:ffff
2032920:ca0::/282920:caf:ffff:ffff:ffff:ffff:ffff:ffff
2042920:cb0::/282920:cbf:ffff:ffff:ffff:ffff:ffff:ffff
2052920:cc0::/282920:ccf:ffff:ffff:ffff:ffff:ffff:ffff
2062920:cd0::/282920:cdf:ffff:ffff:ffff:ffff:ffff:ffff
2072920:ce0::/282920:cef:ffff:ffff:ffff:ffff:ffff:ffff
2082920:cf0::/282920:cff:ffff:ffff:ffff:ffff:ffff:ffff
2092920:d00::/282920:d0f:ffff:ffff:ffff:ffff:ffff:ffff
2102920:d10::/282920:d1f:ffff:ffff:ffff:ffff:ffff:ffff
2112920:d20::/282920:d2f:ffff:ffff:ffff:ffff:ffff:ffff
2122920:d30::/282920:d3f:ffff:ffff:ffff:ffff:ffff:ffff
2132920:d40::/282920:d4f:ffff:ffff:ffff:ffff:ffff:ffff
2142920:d50::/282920:d5f:ffff:ffff:ffff:ffff:ffff:ffff
2152920:d60::/282920:d6f:ffff:ffff:ffff:ffff:ffff:ffff
2162920:d70::/282920:d7f:ffff:ffff:ffff:ffff:ffff:ffff
2172920:d80::/282920:d8f:ffff:ffff:ffff:ffff:ffff:ffff
2182920:d90::/282920:d9f:ffff:ffff:ffff:ffff:ffff:ffff
2192920:da0::/282920:daf:ffff:ffff:ffff:ffff:ffff:ffff
2202920:db0::/282920:dbf:ffff:ffff:ffff:ffff:ffff:ffff
2212920:dc0::/282920:dcf:ffff:ffff:ffff:ffff:ffff:ffff
2222920:dd0::/282920:ddf:ffff:ffff:ffff:ffff:ffff:ffff
2232920:de0::/282920:def:ffff:ffff:ffff:ffff:ffff:ffff
2242920:df0::/282920:dff:ffff:ffff:ffff:ffff:ffff:ffff
2252920:e00::/282920:e0f:ffff:ffff:ffff:ffff:ffff:ffff
2262920:e10::/282920:e1f:ffff:ffff:ffff:ffff:ffff:ffff
2272920:e20::/282920:e2f:ffff:ffff:ffff:ffff:ffff:ffff
2282920:e30::/282920:e3f:ffff:ffff:ffff:ffff:ffff:ffff
2292920:e40::/282920:e4f:ffff:ffff:ffff:ffff:ffff:ffff
2302920:e50::/282920:e5f:ffff:ffff:ffff:ffff:ffff:ffff
2312920:e60::/282920:e6f:ffff:ffff:ffff:ffff:ffff:ffff
2322920:e70::/282920:e7f:ffff:ffff:ffff:ffff:ffff:ffff
2332920:e80::/282920:e8f:ffff:ffff:ffff:ffff:ffff:ffff
2342920:e90::/282920:e9f:ffff:ffff:ffff:ffff:ffff:ffff
2352920:ea0::/282920:eaf:ffff:ffff:ffff:ffff:ffff:ffff
2362920:eb0::/282920:ebf:ffff:ffff:ffff:ffff:ffff:ffff
2372920:ec0::/282920:ecf:ffff:ffff:ffff:ffff:ffff:ffff
2382920:ed0::/282920:edf:ffff:ffff:ffff:ffff:ffff:ffff
2392920:ee0::/282920:eef:ffff:ffff:ffff:ffff:ffff:ffff
2402920:ef0::/282920:eff:ffff:ffff:ffff:ffff:ffff:ffff
2412920:f00::/282920:f0f:ffff:ffff:ffff:ffff:ffff:ffff
2422920:f10::/282920:f1f:ffff:ffff:ffff:ffff:ffff:ffff
2432920:f20::/282920:f2f:ffff:ffff:ffff:ffff:ffff:ffff
2442920:f30::/282920:f3f:ffff:ffff:ffff:ffff:ffff:ffff
2452920:f40::/282920:f4f:ffff:ffff:ffff:ffff:ffff:ffff
2462920:f50::/282920:f5f:ffff:ffff:ffff:ffff:ffff:ffff
2472920:f60::/282920:f6f:ffff:ffff:ffff:ffff:ffff:ffff
2482920:f70::/282920:f7f:ffff:ffff:ffff:ffff:ffff:ffff
2492920:f80::/282920:f8f:ffff:ffff:ffff:ffff:ffff:ffff
2502920:f90::/282920:f9f:ffff:ffff:ffff:ffff:ffff:ffff
2512920:fa0::/282920:faf:ffff:ffff:ffff:ffff:ffff:ffff
2522920:fb0::/282920:fbf:ffff:ffff:ffff:ffff:ffff:ffff
2532920:fc0::/282920:fcf:ffff:ffff:ffff:ffff:ffff:ffff
2542920:fd0::/282920:fdf:ffff:ffff:ffff:ffff:ffff:ffff
2552920:fe0::/282920:fef:ffff:ffff:ffff:ffff:ffff:ffff
2562920:ff0::/282920:fff: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.