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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
2270::/12
First address
2270::
Last address
227f: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
2270:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
7.2.2.ip6.arpa
Split into smaller subnets/28
/13 (2)/14 (4)/15 (8)/16 (16)/20 (256)/24 (4,096)/28 (65,536)

2270::/12 makes 65,536 subnets of /28; the first 256 are listed.

Subnets
#SubnetLast address
12270::/282270:f:ffff:ffff:ffff:ffff:ffff:ffff
22270:10::/282270:1f:ffff:ffff:ffff:ffff:ffff:ffff
32270:20::/282270:2f:ffff:ffff:ffff:ffff:ffff:ffff
42270:30::/282270:3f:ffff:ffff:ffff:ffff:ffff:ffff
52270:40::/282270:4f:ffff:ffff:ffff:ffff:ffff:ffff
62270:50::/282270:5f:ffff:ffff:ffff:ffff:ffff:ffff
72270:60::/282270:6f:ffff:ffff:ffff:ffff:ffff:ffff
82270:70::/282270:7f:ffff:ffff:ffff:ffff:ffff:ffff
92270:80::/282270:8f:ffff:ffff:ffff:ffff:ffff:ffff
102270:90::/282270:9f:ffff:ffff:ffff:ffff:ffff:ffff
112270:a0::/282270:af:ffff:ffff:ffff:ffff:ffff:ffff
122270:b0::/282270:bf:ffff:ffff:ffff:ffff:ffff:ffff
132270:c0::/282270:cf:ffff:ffff:ffff:ffff:ffff:ffff
142270:d0::/282270:df:ffff:ffff:ffff:ffff:ffff:ffff
152270:e0::/282270:ef:ffff:ffff:ffff:ffff:ffff:ffff
162270:f0::/282270:ff:ffff:ffff:ffff:ffff:ffff:ffff
172270:100::/282270:10f:ffff:ffff:ffff:ffff:ffff:ffff
182270:110::/282270:11f:ffff:ffff:ffff:ffff:ffff:ffff
192270:120::/282270:12f:ffff:ffff:ffff:ffff:ffff:ffff
202270:130::/282270:13f:ffff:ffff:ffff:ffff:ffff:ffff
212270:140::/282270:14f:ffff:ffff:ffff:ffff:ffff:ffff
222270:150::/282270:15f:ffff:ffff:ffff:ffff:ffff:ffff
232270:160::/282270:16f:ffff:ffff:ffff:ffff:ffff:ffff
242270:170::/282270:17f:ffff:ffff:ffff:ffff:ffff:ffff
252270:180::/282270:18f:ffff:ffff:ffff:ffff:ffff:ffff
262270:190::/282270:19f:ffff:ffff:ffff:ffff:ffff:ffff
272270:1a0::/282270:1af:ffff:ffff:ffff:ffff:ffff:ffff
282270:1b0::/282270:1bf:ffff:ffff:ffff:ffff:ffff:ffff
292270:1c0::/282270:1cf:ffff:ffff:ffff:ffff:ffff:ffff
302270:1d0::/282270:1df:ffff:ffff:ffff:ffff:ffff:ffff
312270:1e0::/282270:1ef:ffff:ffff:ffff:ffff:ffff:ffff
322270:1f0::/282270:1ff:ffff:ffff:ffff:ffff:ffff:ffff
332270:200::/282270:20f:ffff:ffff:ffff:ffff:ffff:ffff
342270:210::/282270:21f:ffff:ffff:ffff:ffff:ffff:ffff
352270:220::/282270:22f:ffff:ffff:ffff:ffff:ffff:ffff
362270:230::/282270:23f:ffff:ffff:ffff:ffff:ffff:ffff
372270:240::/282270:24f:ffff:ffff:ffff:ffff:ffff:ffff
382270:250::/282270:25f:ffff:ffff:ffff:ffff:ffff:ffff
392270:260::/282270:26f:ffff:ffff:ffff:ffff:ffff:ffff
402270:270::/282270:27f:ffff:ffff:ffff:ffff:ffff:ffff
412270:280::/282270:28f:ffff:ffff:ffff:ffff:ffff:ffff
422270:290::/282270:29f:ffff:ffff:ffff:ffff:ffff:ffff
432270:2a0::/282270:2af:ffff:ffff:ffff:ffff:ffff:ffff
442270:2b0::/282270:2bf:ffff:ffff:ffff:ffff:ffff:ffff
452270:2c0::/282270:2cf:ffff:ffff:ffff:ffff:ffff:ffff
462270:2d0::/282270:2df:ffff:ffff:ffff:ffff:ffff:ffff
472270:2e0::/282270:2ef:ffff:ffff:ffff:ffff:ffff:ffff
482270:2f0::/282270:2ff:ffff:ffff:ffff:ffff:ffff:ffff
492270:300::/282270:30f:ffff:ffff:ffff:ffff:ffff:ffff
502270:310::/282270:31f:ffff:ffff:ffff:ffff:ffff:ffff
512270:320::/282270:32f:ffff:ffff:ffff:ffff:ffff:ffff
522270:330::/282270:33f:ffff:ffff:ffff:ffff:ffff:ffff
532270:340::/282270:34f:ffff:ffff:ffff:ffff:ffff:ffff
542270:350::/282270:35f:ffff:ffff:ffff:ffff:ffff:ffff
552270:360::/282270:36f:ffff:ffff:ffff:ffff:ffff:ffff
562270:370::/282270:37f:ffff:ffff:ffff:ffff:ffff:ffff
572270:380::/282270:38f:ffff:ffff:ffff:ffff:ffff:ffff
582270:390::/282270:39f:ffff:ffff:ffff:ffff:ffff:ffff
592270:3a0::/282270:3af:ffff:ffff:ffff:ffff:ffff:ffff
602270:3b0::/282270:3bf:ffff:ffff:ffff:ffff:ffff:ffff
612270:3c0::/282270:3cf:ffff:ffff:ffff:ffff:ffff:ffff
622270:3d0::/282270:3df:ffff:ffff:ffff:ffff:ffff:ffff
632270:3e0::/282270:3ef:ffff:ffff:ffff:ffff:ffff:ffff
642270:3f0::/282270:3ff:ffff:ffff:ffff:ffff:ffff:ffff
652270:400::/282270:40f:ffff:ffff:ffff:ffff:ffff:ffff
662270:410::/282270:41f:ffff:ffff:ffff:ffff:ffff:ffff
672270:420::/282270:42f:ffff:ffff:ffff:ffff:ffff:ffff
682270:430::/282270:43f:ffff:ffff:ffff:ffff:ffff:ffff
692270:440::/282270:44f:ffff:ffff:ffff:ffff:ffff:ffff
702270:450::/282270:45f:ffff:ffff:ffff:ffff:ffff:ffff
712270:460::/282270:46f:ffff:ffff:ffff:ffff:ffff:ffff
722270:470::/282270:47f:ffff:ffff:ffff:ffff:ffff:ffff
732270:480::/282270:48f:ffff:ffff:ffff:ffff:ffff:ffff
742270:490::/282270:49f:ffff:ffff:ffff:ffff:ffff:ffff
752270:4a0::/282270:4af:ffff:ffff:ffff:ffff:ffff:ffff
762270:4b0::/282270:4bf:ffff:ffff:ffff:ffff:ffff:ffff
772270:4c0::/282270:4cf:ffff:ffff:ffff:ffff:ffff:ffff
782270:4d0::/282270:4df:ffff:ffff:ffff:ffff:ffff:ffff
792270:4e0::/282270:4ef:ffff:ffff:ffff:ffff:ffff:ffff
802270:4f0::/282270:4ff:ffff:ffff:ffff:ffff:ffff:ffff
812270:500::/282270:50f:ffff:ffff:ffff:ffff:ffff:ffff
822270:510::/282270:51f:ffff:ffff:ffff:ffff:ffff:ffff
832270:520::/282270:52f:ffff:ffff:ffff:ffff:ffff:ffff
842270:530::/282270:53f:ffff:ffff:ffff:ffff:ffff:ffff
852270:540::/282270:54f:ffff:ffff:ffff:ffff:ffff:ffff
862270:550::/282270:55f:ffff:ffff:ffff:ffff:ffff:ffff
872270:560::/282270:56f:ffff:ffff:ffff:ffff:ffff:ffff
882270:570::/282270:57f:ffff:ffff:ffff:ffff:ffff:ffff
892270:580::/282270:58f:ffff:ffff:ffff:ffff:ffff:ffff
902270:590::/282270:59f:ffff:ffff:ffff:ffff:ffff:ffff
912270:5a0::/282270:5af:ffff:ffff:ffff:ffff:ffff:ffff
922270:5b0::/282270:5bf:ffff:ffff:ffff:ffff:ffff:ffff
932270:5c0::/282270:5cf:ffff:ffff:ffff:ffff:ffff:ffff
942270:5d0::/282270:5df:ffff:ffff:ffff:ffff:ffff:ffff
952270:5e0::/282270:5ef:ffff:ffff:ffff:ffff:ffff:ffff
962270:5f0::/282270:5ff:ffff:ffff:ffff:ffff:ffff:ffff
972270:600::/282270:60f:ffff:ffff:ffff:ffff:ffff:ffff
982270:610::/282270:61f:ffff:ffff:ffff:ffff:ffff:ffff
992270:620::/282270:62f:ffff:ffff:ffff:ffff:ffff:ffff
1002270:630::/282270:63f:ffff:ffff:ffff:ffff:ffff:ffff
1012270:640::/282270:64f:ffff:ffff:ffff:ffff:ffff:ffff
1022270:650::/282270:65f:ffff:ffff:ffff:ffff:ffff:ffff
1032270:660::/282270:66f:ffff:ffff:ffff:ffff:ffff:ffff
1042270:670::/282270:67f:ffff:ffff:ffff:ffff:ffff:ffff
1052270:680::/282270:68f:ffff:ffff:ffff:ffff:ffff:ffff
1062270:690::/282270:69f:ffff:ffff:ffff:ffff:ffff:ffff
1072270:6a0::/282270:6af:ffff:ffff:ffff:ffff:ffff:ffff
1082270:6b0::/282270:6bf:ffff:ffff:ffff:ffff:ffff:ffff
1092270:6c0::/282270:6cf:ffff:ffff:ffff:ffff:ffff:ffff
1102270:6d0::/282270:6df:ffff:ffff:ffff:ffff:ffff:ffff
1112270:6e0::/282270:6ef:ffff:ffff:ffff:ffff:ffff:ffff
1122270:6f0::/282270:6ff:ffff:ffff:ffff:ffff:ffff:ffff
1132270:700::/282270:70f:ffff:ffff:ffff:ffff:ffff:ffff
1142270:710::/282270:71f:ffff:ffff:ffff:ffff:ffff:ffff
1152270:720::/282270:72f:ffff:ffff:ffff:ffff:ffff:ffff
1162270:730::/282270:73f:ffff:ffff:ffff:ffff:ffff:ffff
1172270:740::/282270:74f:ffff:ffff:ffff:ffff:ffff:ffff
1182270:750::/282270:75f:ffff:ffff:ffff:ffff:ffff:ffff
1192270:760::/282270:76f:ffff:ffff:ffff:ffff:ffff:ffff
1202270:770::/282270:77f:ffff:ffff:ffff:ffff:ffff:ffff
1212270:780::/282270:78f:ffff:ffff:ffff:ffff:ffff:ffff
1222270:790::/282270:79f:ffff:ffff:ffff:ffff:ffff:ffff
1232270:7a0::/282270:7af:ffff:ffff:ffff:ffff:ffff:ffff
1242270:7b0::/282270:7bf:ffff:ffff:ffff:ffff:ffff:ffff
1252270:7c0::/282270:7cf:ffff:ffff:ffff:ffff:ffff:ffff
1262270:7d0::/282270:7df:ffff:ffff:ffff:ffff:ffff:ffff
1272270:7e0::/282270:7ef:ffff:ffff:ffff:ffff:ffff:ffff
1282270:7f0::/282270:7ff:ffff:ffff:ffff:ffff:ffff:ffff
1292270:800::/282270:80f:ffff:ffff:ffff:ffff:ffff:ffff
1302270:810::/282270:81f:ffff:ffff:ffff:ffff:ffff:ffff
1312270:820::/282270:82f:ffff:ffff:ffff:ffff:ffff:ffff
1322270:830::/282270:83f:ffff:ffff:ffff:ffff:ffff:ffff
1332270:840::/282270:84f:ffff:ffff:ffff:ffff:ffff:ffff
1342270:850::/282270:85f:ffff:ffff:ffff:ffff:ffff:ffff
1352270:860::/282270:86f:ffff:ffff:ffff:ffff:ffff:ffff
1362270:870::/282270:87f:ffff:ffff:ffff:ffff:ffff:ffff
1372270:880::/282270:88f:ffff:ffff:ffff:ffff:ffff:ffff
1382270:890::/282270:89f:ffff:ffff:ffff:ffff:ffff:ffff
1392270:8a0::/282270:8af:ffff:ffff:ffff:ffff:ffff:ffff
1402270:8b0::/282270:8bf:ffff:ffff:ffff:ffff:ffff:ffff
1412270:8c0::/282270:8cf:ffff:ffff:ffff:ffff:ffff:ffff
1422270:8d0::/282270:8df:ffff:ffff:ffff:ffff:ffff:ffff
1432270:8e0::/282270:8ef:ffff:ffff:ffff:ffff:ffff:ffff
1442270:8f0::/282270:8ff:ffff:ffff:ffff:ffff:ffff:ffff
1452270:900::/282270:90f:ffff:ffff:ffff:ffff:ffff:ffff
1462270:910::/282270:91f:ffff:ffff:ffff:ffff:ffff:ffff
1472270:920::/282270:92f:ffff:ffff:ffff:ffff:ffff:ffff
1482270:930::/282270:93f:ffff:ffff:ffff:ffff:ffff:ffff
1492270:940::/282270:94f:ffff:ffff:ffff:ffff:ffff:ffff
1502270:950::/282270:95f:ffff:ffff:ffff:ffff:ffff:ffff
1512270:960::/282270:96f:ffff:ffff:ffff:ffff:ffff:ffff
1522270:970::/282270:97f:ffff:ffff:ffff:ffff:ffff:ffff
1532270:980::/282270:98f:ffff:ffff:ffff:ffff:ffff:ffff
1542270:990::/282270:99f:ffff:ffff:ffff:ffff:ffff:ffff
1552270:9a0::/282270:9af:ffff:ffff:ffff:ffff:ffff:ffff
1562270:9b0::/282270:9bf:ffff:ffff:ffff:ffff:ffff:ffff
1572270:9c0::/282270:9cf:ffff:ffff:ffff:ffff:ffff:ffff
1582270:9d0::/282270:9df:ffff:ffff:ffff:ffff:ffff:ffff
1592270:9e0::/282270:9ef:ffff:ffff:ffff:ffff:ffff:ffff
1602270:9f0::/282270:9ff:ffff:ffff:ffff:ffff:ffff:ffff
1612270:a00::/282270:a0f:ffff:ffff:ffff:ffff:ffff:ffff
1622270:a10::/282270:a1f:ffff:ffff:ffff:ffff:ffff:ffff
1632270:a20::/282270:a2f:ffff:ffff:ffff:ffff:ffff:ffff
1642270:a30::/282270:a3f:ffff:ffff:ffff:ffff:ffff:ffff
1652270:a40::/282270:a4f:ffff:ffff:ffff:ffff:ffff:ffff
1662270:a50::/282270:a5f:ffff:ffff:ffff:ffff:ffff:ffff
1672270:a60::/282270:a6f:ffff:ffff:ffff:ffff:ffff:ffff
1682270:a70::/282270:a7f:ffff:ffff:ffff:ffff:ffff:ffff
1692270:a80::/282270:a8f:ffff:ffff:ffff:ffff:ffff:ffff
1702270:a90::/282270:a9f:ffff:ffff:ffff:ffff:ffff:ffff
1712270:aa0::/282270:aaf:ffff:ffff:ffff:ffff:ffff:ffff
1722270:ab0::/282270:abf:ffff:ffff:ffff:ffff:ffff:ffff
1732270:ac0::/282270:acf:ffff:ffff:ffff:ffff:ffff:ffff
1742270:ad0::/282270:adf:ffff:ffff:ffff:ffff:ffff:ffff
1752270:ae0::/282270:aef:ffff:ffff:ffff:ffff:ffff:ffff
1762270:af0::/282270:aff:ffff:ffff:ffff:ffff:ffff:ffff
1772270:b00::/282270:b0f:ffff:ffff:ffff:ffff:ffff:ffff
1782270:b10::/282270:b1f:ffff:ffff:ffff:ffff:ffff:ffff
1792270:b20::/282270:b2f:ffff:ffff:ffff:ffff:ffff:ffff
1802270:b30::/282270:b3f:ffff:ffff:ffff:ffff:ffff:ffff
1812270:b40::/282270:b4f:ffff:ffff:ffff:ffff:ffff:ffff
1822270:b50::/282270:b5f:ffff:ffff:ffff:ffff:ffff:ffff
1832270:b60::/282270:b6f:ffff:ffff:ffff:ffff:ffff:ffff
1842270:b70::/282270:b7f:ffff:ffff:ffff:ffff:ffff:ffff
1852270:b80::/282270:b8f:ffff:ffff:ffff:ffff:ffff:ffff
1862270:b90::/282270:b9f:ffff:ffff:ffff:ffff:ffff:ffff
1872270:ba0::/282270:baf:ffff:ffff:ffff:ffff:ffff:ffff
1882270:bb0::/282270:bbf:ffff:ffff:ffff:ffff:ffff:ffff
1892270:bc0::/282270:bcf:ffff:ffff:ffff:ffff:ffff:ffff
1902270:bd0::/282270:bdf:ffff:ffff:ffff:ffff:ffff:ffff
1912270:be0::/282270:bef:ffff:ffff:ffff:ffff:ffff:ffff
1922270:bf0::/282270:bff:ffff:ffff:ffff:ffff:ffff:ffff
1932270:c00::/282270:c0f:ffff:ffff:ffff:ffff:ffff:ffff
1942270:c10::/282270:c1f:ffff:ffff:ffff:ffff:ffff:ffff
1952270:c20::/282270:c2f:ffff:ffff:ffff:ffff:ffff:ffff
1962270:c30::/282270:c3f:ffff:ffff:ffff:ffff:ffff:ffff
1972270:c40::/282270:c4f:ffff:ffff:ffff:ffff:ffff:ffff
1982270:c50::/282270:c5f:ffff:ffff:ffff:ffff:ffff:ffff
1992270:c60::/282270:c6f:ffff:ffff:ffff:ffff:ffff:ffff
2002270:c70::/282270:c7f:ffff:ffff:ffff:ffff:ffff:ffff
2012270:c80::/282270:c8f:ffff:ffff:ffff:ffff:ffff:ffff
2022270:c90::/282270:c9f:ffff:ffff:ffff:ffff:ffff:ffff
2032270:ca0::/282270:caf:ffff:ffff:ffff:ffff:ffff:ffff
2042270:cb0::/282270:cbf:ffff:ffff:ffff:ffff:ffff:ffff
2052270:cc0::/282270:ccf:ffff:ffff:ffff:ffff:ffff:ffff
2062270:cd0::/282270:cdf:ffff:ffff:ffff:ffff:ffff:ffff
2072270:ce0::/282270:cef:ffff:ffff:ffff:ffff:ffff:ffff
2082270:cf0::/282270:cff:ffff:ffff:ffff:ffff:ffff:ffff
2092270:d00::/282270:d0f:ffff:ffff:ffff:ffff:ffff:ffff
2102270:d10::/282270:d1f:ffff:ffff:ffff:ffff:ffff:ffff
2112270:d20::/282270:d2f:ffff:ffff:ffff:ffff:ffff:ffff
2122270:d30::/282270:d3f:ffff:ffff:ffff:ffff:ffff:ffff
2132270:d40::/282270:d4f:ffff:ffff:ffff:ffff:ffff:ffff
2142270:d50::/282270:d5f:ffff:ffff:ffff:ffff:ffff:ffff
2152270:d60::/282270:d6f:ffff:ffff:ffff:ffff:ffff:ffff
2162270:d70::/282270:d7f:ffff:ffff:ffff:ffff:ffff:ffff
2172270:d80::/282270:d8f:ffff:ffff:ffff:ffff:ffff:ffff
2182270:d90::/282270:d9f:ffff:ffff:ffff:ffff:ffff:ffff
2192270:da0::/282270:daf:ffff:ffff:ffff:ffff:ffff:ffff
2202270:db0::/282270:dbf:ffff:ffff:ffff:ffff:ffff:ffff
2212270:dc0::/282270:dcf:ffff:ffff:ffff:ffff:ffff:ffff
2222270:dd0::/282270:ddf:ffff:ffff:ffff:ffff:ffff:ffff
2232270:de0::/282270:def:ffff:ffff:ffff:ffff:ffff:ffff
2242270:df0::/282270:dff:ffff:ffff:ffff:ffff:ffff:ffff
2252270:e00::/282270:e0f:ffff:ffff:ffff:ffff:ffff:ffff
2262270:e10::/282270:e1f:ffff:ffff:ffff:ffff:ffff:ffff
2272270:e20::/282270:e2f:ffff:ffff:ffff:ffff:ffff:ffff
2282270:e30::/282270:e3f:ffff:ffff:ffff:ffff:ffff:ffff
2292270:e40::/282270:e4f:ffff:ffff:ffff:ffff:ffff:ffff
2302270:e50::/282270:e5f:ffff:ffff:ffff:ffff:ffff:ffff
2312270:e60::/282270:e6f:ffff:ffff:ffff:ffff:ffff:ffff
2322270:e70::/282270:e7f:ffff:ffff:ffff:ffff:ffff:ffff
2332270:e80::/282270:e8f:ffff:ffff:ffff:ffff:ffff:ffff
2342270:e90::/282270:e9f:ffff:ffff:ffff:ffff:ffff:ffff
2352270:ea0::/282270:eaf:ffff:ffff:ffff:ffff:ffff:ffff
2362270:eb0::/282270:ebf:ffff:ffff:ffff:ffff:ffff:ffff
2372270:ec0::/282270:ecf:ffff:ffff:ffff:ffff:ffff:ffff
2382270:ed0::/282270:edf:ffff:ffff:ffff:ffff:ffff:ffff
2392270:ee0::/282270:eef:ffff:ffff:ffff:ffff:ffff:ffff
2402270:ef0::/282270:eff:ffff:ffff:ffff:ffff:ffff:ffff
2412270:f00::/282270:f0f:ffff:ffff:ffff:ffff:ffff:ffff
2422270:f10::/282270:f1f:ffff:ffff:ffff:ffff:ffff:ffff
2432270:f20::/282270:f2f:ffff:ffff:ffff:ffff:ffff:ffff
2442270:f30::/282270:f3f:ffff:ffff:ffff:ffff:ffff:ffff
2452270:f40::/282270:f4f:ffff:ffff:ffff:ffff:ffff:ffff
2462270:f50::/282270:f5f:ffff:ffff:ffff:ffff:ffff:ffff
2472270:f60::/282270:f6f:ffff:ffff:ffff:ffff:ffff:ffff
2482270:f70::/282270:f7f:ffff:ffff:ffff:ffff:ffff:ffff
2492270:f80::/282270:f8f:ffff:ffff:ffff:ffff:ffff:ffff
2502270:f90::/282270:f9f:ffff:ffff:ffff:ffff:ffff:ffff
2512270:fa0::/282270:faf:ffff:ffff:ffff:ffff:ffff:ffff
2522270:fb0::/282270:fbf:ffff:ffff:ffff:ffff:ffff:ffff
2532270:fc0::/282270:fcf:ffff:ffff:ffff:ffff:ffff:ffff
2542270:fd0::/282270:fdf:ffff:ffff:ffff:ffff:ffff:ffff
2552270:fe0::/282270:fef:ffff:ffff:ffff:ffff:ffff:ffff
2562270:ff0::/282270: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.