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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
2210::/12
First address
2210::
Last address
221f: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
2210:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
1.2.2.ip6.arpa
Split into smaller subnets/28
/13 (2)/14 (4)/15 (8)/16 (16)/20 (256)/24 (4,096)/28 (65,536)

2210::/12 makes 65,536 subnets of /28; the first 256 are listed.

Subnets
#SubnetLast address
12210::/282210:f:ffff:ffff:ffff:ffff:ffff:ffff
22210:10::/282210:1f:ffff:ffff:ffff:ffff:ffff:ffff
32210:20::/282210:2f:ffff:ffff:ffff:ffff:ffff:ffff
42210:30::/282210:3f:ffff:ffff:ffff:ffff:ffff:ffff
52210:40::/282210:4f:ffff:ffff:ffff:ffff:ffff:ffff
62210:50::/282210:5f:ffff:ffff:ffff:ffff:ffff:ffff
72210:60::/282210:6f:ffff:ffff:ffff:ffff:ffff:ffff
82210:70::/282210:7f:ffff:ffff:ffff:ffff:ffff:ffff
92210:80::/282210:8f:ffff:ffff:ffff:ffff:ffff:ffff
102210:90::/282210:9f:ffff:ffff:ffff:ffff:ffff:ffff
112210:a0::/282210:af:ffff:ffff:ffff:ffff:ffff:ffff
122210:b0::/282210:bf:ffff:ffff:ffff:ffff:ffff:ffff
132210:c0::/282210:cf:ffff:ffff:ffff:ffff:ffff:ffff
142210:d0::/282210:df:ffff:ffff:ffff:ffff:ffff:ffff
152210:e0::/282210:ef:ffff:ffff:ffff:ffff:ffff:ffff
162210:f0::/282210:ff:ffff:ffff:ffff:ffff:ffff:ffff
172210:100::/282210:10f:ffff:ffff:ffff:ffff:ffff:ffff
182210:110::/282210:11f:ffff:ffff:ffff:ffff:ffff:ffff
192210:120::/282210:12f:ffff:ffff:ffff:ffff:ffff:ffff
202210:130::/282210:13f:ffff:ffff:ffff:ffff:ffff:ffff
212210:140::/282210:14f:ffff:ffff:ffff:ffff:ffff:ffff
222210:150::/282210:15f:ffff:ffff:ffff:ffff:ffff:ffff
232210:160::/282210:16f:ffff:ffff:ffff:ffff:ffff:ffff
242210:170::/282210:17f:ffff:ffff:ffff:ffff:ffff:ffff
252210:180::/282210:18f:ffff:ffff:ffff:ffff:ffff:ffff
262210:190::/282210:19f:ffff:ffff:ffff:ffff:ffff:ffff
272210:1a0::/282210:1af:ffff:ffff:ffff:ffff:ffff:ffff
282210:1b0::/282210:1bf:ffff:ffff:ffff:ffff:ffff:ffff
292210:1c0::/282210:1cf:ffff:ffff:ffff:ffff:ffff:ffff
302210:1d0::/282210:1df:ffff:ffff:ffff:ffff:ffff:ffff
312210:1e0::/282210:1ef:ffff:ffff:ffff:ffff:ffff:ffff
322210:1f0::/282210:1ff:ffff:ffff:ffff:ffff:ffff:ffff
332210:200::/282210:20f:ffff:ffff:ffff:ffff:ffff:ffff
342210:210::/282210:21f:ffff:ffff:ffff:ffff:ffff:ffff
352210:220::/282210:22f:ffff:ffff:ffff:ffff:ffff:ffff
362210:230::/282210:23f:ffff:ffff:ffff:ffff:ffff:ffff
372210:240::/282210:24f:ffff:ffff:ffff:ffff:ffff:ffff
382210:250::/282210:25f:ffff:ffff:ffff:ffff:ffff:ffff
392210:260::/282210:26f:ffff:ffff:ffff:ffff:ffff:ffff
402210:270::/282210:27f:ffff:ffff:ffff:ffff:ffff:ffff
412210:280::/282210:28f:ffff:ffff:ffff:ffff:ffff:ffff
422210:290::/282210:29f:ffff:ffff:ffff:ffff:ffff:ffff
432210:2a0::/282210:2af:ffff:ffff:ffff:ffff:ffff:ffff
442210:2b0::/282210:2bf:ffff:ffff:ffff:ffff:ffff:ffff
452210:2c0::/282210:2cf:ffff:ffff:ffff:ffff:ffff:ffff
462210:2d0::/282210:2df:ffff:ffff:ffff:ffff:ffff:ffff
472210:2e0::/282210:2ef:ffff:ffff:ffff:ffff:ffff:ffff
482210:2f0::/282210:2ff:ffff:ffff:ffff:ffff:ffff:ffff
492210:300::/282210:30f:ffff:ffff:ffff:ffff:ffff:ffff
502210:310::/282210:31f:ffff:ffff:ffff:ffff:ffff:ffff
512210:320::/282210:32f:ffff:ffff:ffff:ffff:ffff:ffff
522210:330::/282210:33f:ffff:ffff:ffff:ffff:ffff:ffff
532210:340::/282210:34f:ffff:ffff:ffff:ffff:ffff:ffff
542210:350::/282210:35f:ffff:ffff:ffff:ffff:ffff:ffff
552210:360::/282210:36f:ffff:ffff:ffff:ffff:ffff:ffff
562210:370::/282210:37f:ffff:ffff:ffff:ffff:ffff:ffff
572210:380::/282210:38f:ffff:ffff:ffff:ffff:ffff:ffff
582210:390::/282210:39f:ffff:ffff:ffff:ffff:ffff:ffff
592210:3a0::/282210:3af:ffff:ffff:ffff:ffff:ffff:ffff
602210:3b0::/282210:3bf:ffff:ffff:ffff:ffff:ffff:ffff
612210:3c0::/282210:3cf:ffff:ffff:ffff:ffff:ffff:ffff
622210:3d0::/282210:3df:ffff:ffff:ffff:ffff:ffff:ffff
632210:3e0::/282210:3ef:ffff:ffff:ffff:ffff:ffff:ffff
642210:3f0::/282210:3ff:ffff:ffff:ffff:ffff:ffff:ffff
652210:400::/282210:40f:ffff:ffff:ffff:ffff:ffff:ffff
662210:410::/282210:41f:ffff:ffff:ffff:ffff:ffff:ffff
672210:420::/282210:42f:ffff:ffff:ffff:ffff:ffff:ffff
682210:430::/282210:43f:ffff:ffff:ffff:ffff:ffff:ffff
692210:440::/282210:44f:ffff:ffff:ffff:ffff:ffff:ffff
702210:450::/282210:45f:ffff:ffff:ffff:ffff:ffff:ffff
712210:460::/282210:46f:ffff:ffff:ffff:ffff:ffff:ffff
722210:470::/282210:47f:ffff:ffff:ffff:ffff:ffff:ffff
732210:480::/282210:48f:ffff:ffff:ffff:ffff:ffff:ffff
742210:490::/282210:49f:ffff:ffff:ffff:ffff:ffff:ffff
752210:4a0::/282210:4af:ffff:ffff:ffff:ffff:ffff:ffff
762210:4b0::/282210:4bf:ffff:ffff:ffff:ffff:ffff:ffff
772210:4c0::/282210:4cf:ffff:ffff:ffff:ffff:ffff:ffff
782210:4d0::/282210:4df:ffff:ffff:ffff:ffff:ffff:ffff
792210:4e0::/282210:4ef:ffff:ffff:ffff:ffff:ffff:ffff
802210:4f0::/282210:4ff:ffff:ffff:ffff:ffff:ffff:ffff
812210:500::/282210:50f:ffff:ffff:ffff:ffff:ffff:ffff
822210:510::/282210:51f:ffff:ffff:ffff:ffff:ffff:ffff
832210:520::/282210:52f:ffff:ffff:ffff:ffff:ffff:ffff
842210:530::/282210:53f:ffff:ffff:ffff:ffff:ffff:ffff
852210:540::/282210:54f:ffff:ffff:ffff:ffff:ffff:ffff
862210:550::/282210:55f:ffff:ffff:ffff:ffff:ffff:ffff
872210:560::/282210:56f:ffff:ffff:ffff:ffff:ffff:ffff
882210:570::/282210:57f:ffff:ffff:ffff:ffff:ffff:ffff
892210:580::/282210:58f:ffff:ffff:ffff:ffff:ffff:ffff
902210:590::/282210:59f:ffff:ffff:ffff:ffff:ffff:ffff
912210:5a0::/282210:5af:ffff:ffff:ffff:ffff:ffff:ffff
922210:5b0::/282210:5bf:ffff:ffff:ffff:ffff:ffff:ffff
932210:5c0::/282210:5cf:ffff:ffff:ffff:ffff:ffff:ffff
942210:5d0::/282210:5df:ffff:ffff:ffff:ffff:ffff:ffff
952210:5e0::/282210:5ef:ffff:ffff:ffff:ffff:ffff:ffff
962210:5f0::/282210:5ff:ffff:ffff:ffff:ffff:ffff:ffff
972210:600::/282210:60f:ffff:ffff:ffff:ffff:ffff:ffff
982210:610::/282210:61f:ffff:ffff:ffff:ffff:ffff:ffff
992210:620::/282210:62f:ffff:ffff:ffff:ffff:ffff:ffff
1002210:630::/282210:63f:ffff:ffff:ffff:ffff:ffff:ffff
1012210:640::/282210:64f:ffff:ffff:ffff:ffff:ffff:ffff
1022210:650::/282210:65f:ffff:ffff:ffff:ffff:ffff:ffff
1032210:660::/282210:66f:ffff:ffff:ffff:ffff:ffff:ffff
1042210:670::/282210:67f:ffff:ffff:ffff:ffff:ffff:ffff
1052210:680::/282210:68f:ffff:ffff:ffff:ffff:ffff:ffff
1062210:690::/282210:69f:ffff:ffff:ffff:ffff:ffff:ffff
1072210:6a0::/282210:6af:ffff:ffff:ffff:ffff:ffff:ffff
1082210:6b0::/282210:6bf:ffff:ffff:ffff:ffff:ffff:ffff
1092210:6c0::/282210:6cf:ffff:ffff:ffff:ffff:ffff:ffff
1102210:6d0::/282210:6df:ffff:ffff:ffff:ffff:ffff:ffff
1112210:6e0::/282210:6ef:ffff:ffff:ffff:ffff:ffff:ffff
1122210:6f0::/282210:6ff:ffff:ffff:ffff:ffff:ffff:ffff
1132210:700::/282210:70f:ffff:ffff:ffff:ffff:ffff:ffff
1142210:710::/282210:71f:ffff:ffff:ffff:ffff:ffff:ffff
1152210:720::/282210:72f:ffff:ffff:ffff:ffff:ffff:ffff
1162210:730::/282210:73f:ffff:ffff:ffff:ffff:ffff:ffff
1172210:740::/282210:74f:ffff:ffff:ffff:ffff:ffff:ffff
1182210:750::/282210:75f:ffff:ffff:ffff:ffff:ffff:ffff
1192210:760::/282210:76f:ffff:ffff:ffff:ffff:ffff:ffff
1202210:770::/282210:77f:ffff:ffff:ffff:ffff:ffff:ffff
1212210:780::/282210:78f:ffff:ffff:ffff:ffff:ffff:ffff
1222210:790::/282210:79f:ffff:ffff:ffff:ffff:ffff:ffff
1232210:7a0::/282210:7af:ffff:ffff:ffff:ffff:ffff:ffff
1242210:7b0::/282210:7bf:ffff:ffff:ffff:ffff:ffff:ffff
1252210:7c0::/282210:7cf:ffff:ffff:ffff:ffff:ffff:ffff
1262210:7d0::/282210:7df:ffff:ffff:ffff:ffff:ffff:ffff
1272210:7e0::/282210:7ef:ffff:ffff:ffff:ffff:ffff:ffff
1282210:7f0::/282210:7ff:ffff:ffff:ffff:ffff:ffff:ffff
1292210:800::/282210:80f:ffff:ffff:ffff:ffff:ffff:ffff
1302210:810::/282210:81f:ffff:ffff:ffff:ffff:ffff:ffff
1312210:820::/282210:82f:ffff:ffff:ffff:ffff:ffff:ffff
1322210:830::/282210:83f:ffff:ffff:ffff:ffff:ffff:ffff
1332210:840::/282210:84f:ffff:ffff:ffff:ffff:ffff:ffff
1342210:850::/282210:85f:ffff:ffff:ffff:ffff:ffff:ffff
1352210:860::/282210:86f:ffff:ffff:ffff:ffff:ffff:ffff
1362210:870::/282210:87f:ffff:ffff:ffff:ffff:ffff:ffff
1372210:880::/282210:88f:ffff:ffff:ffff:ffff:ffff:ffff
1382210:890::/282210:89f:ffff:ffff:ffff:ffff:ffff:ffff
1392210:8a0::/282210:8af:ffff:ffff:ffff:ffff:ffff:ffff
1402210:8b0::/282210:8bf:ffff:ffff:ffff:ffff:ffff:ffff
1412210:8c0::/282210:8cf:ffff:ffff:ffff:ffff:ffff:ffff
1422210:8d0::/282210:8df:ffff:ffff:ffff:ffff:ffff:ffff
1432210:8e0::/282210:8ef:ffff:ffff:ffff:ffff:ffff:ffff
1442210:8f0::/282210:8ff:ffff:ffff:ffff:ffff:ffff:ffff
1452210:900::/282210:90f:ffff:ffff:ffff:ffff:ffff:ffff
1462210:910::/282210:91f:ffff:ffff:ffff:ffff:ffff:ffff
1472210:920::/282210:92f:ffff:ffff:ffff:ffff:ffff:ffff
1482210:930::/282210:93f:ffff:ffff:ffff:ffff:ffff:ffff
1492210:940::/282210:94f:ffff:ffff:ffff:ffff:ffff:ffff
1502210:950::/282210:95f:ffff:ffff:ffff:ffff:ffff:ffff
1512210:960::/282210:96f:ffff:ffff:ffff:ffff:ffff:ffff
1522210:970::/282210:97f:ffff:ffff:ffff:ffff:ffff:ffff
1532210:980::/282210:98f:ffff:ffff:ffff:ffff:ffff:ffff
1542210:990::/282210:99f:ffff:ffff:ffff:ffff:ffff:ffff
1552210:9a0::/282210:9af:ffff:ffff:ffff:ffff:ffff:ffff
1562210:9b0::/282210:9bf:ffff:ffff:ffff:ffff:ffff:ffff
1572210:9c0::/282210:9cf:ffff:ffff:ffff:ffff:ffff:ffff
1582210:9d0::/282210:9df:ffff:ffff:ffff:ffff:ffff:ffff
1592210:9e0::/282210:9ef:ffff:ffff:ffff:ffff:ffff:ffff
1602210:9f0::/282210:9ff:ffff:ffff:ffff:ffff:ffff:ffff
1612210:a00::/282210:a0f:ffff:ffff:ffff:ffff:ffff:ffff
1622210:a10::/282210:a1f:ffff:ffff:ffff:ffff:ffff:ffff
1632210:a20::/282210:a2f:ffff:ffff:ffff:ffff:ffff:ffff
1642210:a30::/282210:a3f:ffff:ffff:ffff:ffff:ffff:ffff
1652210:a40::/282210:a4f:ffff:ffff:ffff:ffff:ffff:ffff
1662210:a50::/282210:a5f:ffff:ffff:ffff:ffff:ffff:ffff
1672210:a60::/282210:a6f:ffff:ffff:ffff:ffff:ffff:ffff
1682210:a70::/282210:a7f:ffff:ffff:ffff:ffff:ffff:ffff
1692210:a80::/282210:a8f:ffff:ffff:ffff:ffff:ffff:ffff
1702210:a90::/282210:a9f:ffff:ffff:ffff:ffff:ffff:ffff
1712210:aa0::/282210:aaf:ffff:ffff:ffff:ffff:ffff:ffff
1722210:ab0::/282210:abf:ffff:ffff:ffff:ffff:ffff:ffff
1732210:ac0::/282210:acf:ffff:ffff:ffff:ffff:ffff:ffff
1742210:ad0::/282210:adf:ffff:ffff:ffff:ffff:ffff:ffff
1752210:ae0::/282210:aef:ffff:ffff:ffff:ffff:ffff:ffff
1762210:af0::/282210:aff:ffff:ffff:ffff:ffff:ffff:ffff
1772210:b00::/282210:b0f:ffff:ffff:ffff:ffff:ffff:ffff
1782210:b10::/282210:b1f:ffff:ffff:ffff:ffff:ffff:ffff
1792210:b20::/282210:b2f:ffff:ffff:ffff:ffff:ffff:ffff
1802210:b30::/282210:b3f:ffff:ffff:ffff:ffff:ffff:ffff
1812210:b40::/282210:b4f:ffff:ffff:ffff:ffff:ffff:ffff
1822210:b50::/282210:b5f:ffff:ffff:ffff:ffff:ffff:ffff
1832210:b60::/282210:b6f:ffff:ffff:ffff:ffff:ffff:ffff
1842210:b70::/282210:b7f:ffff:ffff:ffff:ffff:ffff:ffff
1852210:b80::/282210:b8f:ffff:ffff:ffff:ffff:ffff:ffff
1862210:b90::/282210:b9f:ffff:ffff:ffff:ffff:ffff:ffff
1872210:ba0::/282210:baf:ffff:ffff:ffff:ffff:ffff:ffff
1882210:bb0::/282210:bbf:ffff:ffff:ffff:ffff:ffff:ffff
1892210:bc0::/282210:bcf:ffff:ffff:ffff:ffff:ffff:ffff
1902210:bd0::/282210:bdf:ffff:ffff:ffff:ffff:ffff:ffff
1912210:be0::/282210:bef:ffff:ffff:ffff:ffff:ffff:ffff
1922210:bf0::/282210:bff:ffff:ffff:ffff:ffff:ffff:ffff
1932210:c00::/282210:c0f:ffff:ffff:ffff:ffff:ffff:ffff
1942210:c10::/282210:c1f:ffff:ffff:ffff:ffff:ffff:ffff
1952210:c20::/282210:c2f:ffff:ffff:ffff:ffff:ffff:ffff
1962210:c30::/282210:c3f:ffff:ffff:ffff:ffff:ffff:ffff
1972210:c40::/282210:c4f:ffff:ffff:ffff:ffff:ffff:ffff
1982210:c50::/282210:c5f:ffff:ffff:ffff:ffff:ffff:ffff
1992210:c60::/282210:c6f:ffff:ffff:ffff:ffff:ffff:ffff
2002210:c70::/282210:c7f:ffff:ffff:ffff:ffff:ffff:ffff
2012210:c80::/282210:c8f:ffff:ffff:ffff:ffff:ffff:ffff
2022210:c90::/282210:c9f:ffff:ffff:ffff:ffff:ffff:ffff
2032210:ca0::/282210:caf:ffff:ffff:ffff:ffff:ffff:ffff
2042210:cb0::/282210:cbf:ffff:ffff:ffff:ffff:ffff:ffff
2052210:cc0::/282210:ccf:ffff:ffff:ffff:ffff:ffff:ffff
2062210:cd0::/282210:cdf:ffff:ffff:ffff:ffff:ffff:ffff
2072210:ce0::/282210:cef:ffff:ffff:ffff:ffff:ffff:ffff
2082210:cf0::/282210:cff:ffff:ffff:ffff:ffff:ffff:ffff
2092210:d00::/282210:d0f:ffff:ffff:ffff:ffff:ffff:ffff
2102210:d10::/282210:d1f:ffff:ffff:ffff:ffff:ffff:ffff
2112210:d20::/282210:d2f:ffff:ffff:ffff:ffff:ffff:ffff
2122210:d30::/282210:d3f:ffff:ffff:ffff:ffff:ffff:ffff
2132210:d40::/282210:d4f:ffff:ffff:ffff:ffff:ffff:ffff
2142210:d50::/282210:d5f:ffff:ffff:ffff:ffff:ffff:ffff
2152210:d60::/282210:d6f:ffff:ffff:ffff:ffff:ffff:ffff
2162210:d70::/282210:d7f:ffff:ffff:ffff:ffff:ffff:ffff
2172210:d80::/282210:d8f:ffff:ffff:ffff:ffff:ffff:ffff
2182210:d90::/282210:d9f:ffff:ffff:ffff:ffff:ffff:ffff
2192210:da0::/282210:daf:ffff:ffff:ffff:ffff:ffff:ffff
2202210:db0::/282210:dbf:ffff:ffff:ffff:ffff:ffff:ffff
2212210:dc0::/282210:dcf:ffff:ffff:ffff:ffff:ffff:ffff
2222210:dd0::/282210:ddf:ffff:ffff:ffff:ffff:ffff:ffff
2232210:de0::/282210:def:ffff:ffff:ffff:ffff:ffff:ffff
2242210:df0::/282210:dff:ffff:ffff:ffff:ffff:ffff:ffff
2252210:e00::/282210:e0f:ffff:ffff:ffff:ffff:ffff:ffff
2262210:e10::/282210:e1f:ffff:ffff:ffff:ffff:ffff:ffff
2272210:e20::/282210:e2f:ffff:ffff:ffff:ffff:ffff:ffff
2282210:e30::/282210:e3f:ffff:ffff:ffff:ffff:ffff:ffff
2292210:e40::/282210:e4f:ffff:ffff:ffff:ffff:ffff:ffff
2302210:e50::/282210:e5f:ffff:ffff:ffff:ffff:ffff:ffff
2312210:e60::/282210:e6f:ffff:ffff:ffff:ffff:ffff:ffff
2322210:e70::/282210:e7f:ffff:ffff:ffff:ffff:ffff:ffff
2332210:e80::/282210:e8f:ffff:ffff:ffff:ffff:ffff:ffff
2342210:e90::/282210:e9f:ffff:ffff:ffff:ffff:ffff:ffff
2352210:ea0::/282210:eaf:ffff:ffff:ffff:ffff:ffff:ffff
2362210:eb0::/282210:ebf:ffff:ffff:ffff:ffff:ffff:ffff
2372210:ec0::/282210:ecf:ffff:ffff:ffff:ffff:ffff:ffff
2382210:ed0::/282210:edf:ffff:ffff:ffff:ffff:ffff:ffff
2392210:ee0::/282210:eef:ffff:ffff:ffff:ffff:ffff:ffff
2402210:ef0::/282210:eff:ffff:ffff:ffff:ffff:ffff:ffff
2412210:f00::/282210:f0f:ffff:ffff:ffff:ffff:ffff:ffff
2422210:f10::/282210:f1f:ffff:ffff:ffff:ffff:ffff:ffff
2432210:f20::/282210:f2f:ffff:ffff:ffff:ffff:ffff:ffff
2442210:f30::/282210:f3f:ffff:ffff:ffff:ffff:ffff:ffff
2452210:f40::/282210:f4f:ffff:ffff:ffff:ffff:ffff:ffff
2462210:f50::/282210:f5f:ffff:ffff:ffff:ffff:ffff:ffff
2472210:f60::/282210:f6f:ffff:ffff:ffff:ffff:ffff:ffff
2482210:f70::/282210:f7f:ffff:ffff:ffff:ffff:ffff:ffff
2492210:f80::/282210:f8f:ffff:ffff:ffff:ffff:ffff:ffff
2502210:f90::/282210:f9f:ffff:ffff:ffff:ffff:ffff:ffff
2512210:fa0::/282210:faf:ffff:ffff:ffff:ffff:ffff:ffff
2522210:fb0::/282210:fbf:ffff:ffff:ffff:ffff:ffff:ffff
2532210:fc0::/282210:fcf:ffff:ffff:ffff:ffff:ffff:ffff
2542210:fd0::/282210:fdf:ffff:ffff:ffff:ffff:ffff:ffff
2552210:fe0::/282210:fef:ffff:ffff:ffff:ffff:ffff:ffff
2562210:ff0::/282210: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.