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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
2710::/12
First address
2710::
Last address
271f: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
2710:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
1.7.2.ip6.arpa
Split into smaller subnets/28
/13 (2)/14 (4)/15 (8)/16 (16)/20 (256)/24 (4,096)/28 (65,536)

2710::/12 makes 65,536 subnets of /28; the first 256 are listed.

Subnets
#SubnetLast address
12710::/282710:f:ffff:ffff:ffff:ffff:ffff:ffff
22710:10::/282710:1f:ffff:ffff:ffff:ffff:ffff:ffff
32710:20::/282710:2f:ffff:ffff:ffff:ffff:ffff:ffff
42710:30::/282710:3f:ffff:ffff:ffff:ffff:ffff:ffff
52710:40::/282710:4f:ffff:ffff:ffff:ffff:ffff:ffff
62710:50::/282710:5f:ffff:ffff:ffff:ffff:ffff:ffff
72710:60::/282710:6f:ffff:ffff:ffff:ffff:ffff:ffff
82710:70::/282710:7f:ffff:ffff:ffff:ffff:ffff:ffff
92710:80::/282710:8f:ffff:ffff:ffff:ffff:ffff:ffff
102710:90::/282710:9f:ffff:ffff:ffff:ffff:ffff:ffff
112710:a0::/282710:af:ffff:ffff:ffff:ffff:ffff:ffff
122710:b0::/282710:bf:ffff:ffff:ffff:ffff:ffff:ffff
132710:c0::/282710:cf:ffff:ffff:ffff:ffff:ffff:ffff
142710:d0::/282710:df:ffff:ffff:ffff:ffff:ffff:ffff
152710:e0::/282710:ef:ffff:ffff:ffff:ffff:ffff:ffff
162710:f0::/282710:ff:ffff:ffff:ffff:ffff:ffff:ffff
172710:100::/282710:10f:ffff:ffff:ffff:ffff:ffff:ffff
182710:110::/282710:11f:ffff:ffff:ffff:ffff:ffff:ffff
192710:120::/282710:12f:ffff:ffff:ffff:ffff:ffff:ffff
202710:130::/282710:13f:ffff:ffff:ffff:ffff:ffff:ffff
212710:140::/282710:14f:ffff:ffff:ffff:ffff:ffff:ffff
222710:150::/282710:15f:ffff:ffff:ffff:ffff:ffff:ffff
232710:160::/282710:16f:ffff:ffff:ffff:ffff:ffff:ffff
242710:170::/282710:17f:ffff:ffff:ffff:ffff:ffff:ffff
252710:180::/282710:18f:ffff:ffff:ffff:ffff:ffff:ffff
262710:190::/282710:19f:ffff:ffff:ffff:ffff:ffff:ffff
272710:1a0::/282710:1af:ffff:ffff:ffff:ffff:ffff:ffff
282710:1b0::/282710:1bf:ffff:ffff:ffff:ffff:ffff:ffff
292710:1c0::/282710:1cf:ffff:ffff:ffff:ffff:ffff:ffff
302710:1d0::/282710:1df:ffff:ffff:ffff:ffff:ffff:ffff
312710:1e0::/282710:1ef:ffff:ffff:ffff:ffff:ffff:ffff
322710:1f0::/282710:1ff:ffff:ffff:ffff:ffff:ffff:ffff
332710:200::/282710:20f:ffff:ffff:ffff:ffff:ffff:ffff
342710:210::/282710:21f:ffff:ffff:ffff:ffff:ffff:ffff
352710:220::/282710:22f:ffff:ffff:ffff:ffff:ffff:ffff
362710:230::/282710:23f:ffff:ffff:ffff:ffff:ffff:ffff
372710:240::/282710:24f:ffff:ffff:ffff:ffff:ffff:ffff
382710:250::/282710:25f:ffff:ffff:ffff:ffff:ffff:ffff
392710:260::/282710:26f:ffff:ffff:ffff:ffff:ffff:ffff
402710:270::/282710:27f:ffff:ffff:ffff:ffff:ffff:ffff
412710:280::/282710:28f:ffff:ffff:ffff:ffff:ffff:ffff
422710:290::/282710:29f:ffff:ffff:ffff:ffff:ffff:ffff
432710:2a0::/282710:2af:ffff:ffff:ffff:ffff:ffff:ffff
442710:2b0::/282710:2bf:ffff:ffff:ffff:ffff:ffff:ffff
452710:2c0::/282710:2cf:ffff:ffff:ffff:ffff:ffff:ffff
462710:2d0::/282710:2df:ffff:ffff:ffff:ffff:ffff:ffff
472710:2e0::/282710:2ef:ffff:ffff:ffff:ffff:ffff:ffff
482710:2f0::/282710:2ff:ffff:ffff:ffff:ffff:ffff:ffff
492710:300::/282710:30f:ffff:ffff:ffff:ffff:ffff:ffff
502710:310::/282710:31f:ffff:ffff:ffff:ffff:ffff:ffff
512710:320::/282710:32f:ffff:ffff:ffff:ffff:ffff:ffff
522710:330::/282710:33f:ffff:ffff:ffff:ffff:ffff:ffff
532710:340::/282710:34f:ffff:ffff:ffff:ffff:ffff:ffff
542710:350::/282710:35f:ffff:ffff:ffff:ffff:ffff:ffff
552710:360::/282710:36f:ffff:ffff:ffff:ffff:ffff:ffff
562710:370::/282710:37f:ffff:ffff:ffff:ffff:ffff:ffff
572710:380::/282710:38f:ffff:ffff:ffff:ffff:ffff:ffff
582710:390::/282710:39f:ffff:ffff:ffff:ffff:ffff:ffff
592710:3a0::/282710:3af:ffff:ffff:ffff:ffff:ffff:ffff
602710:3b0::/282710:3bf:ffff:ffff:ffff:ffff:ffff:ffff
612710:3c0::/282710:3cf:ffff:ffff:ffff:ffff:ffff:ffff
622710:3d0::/282710:3df:ffff:ffff:ffff:ffff:ffff:ffff
632710:3e0::/282710:3ef:ffff:ffff:ffff:ffff:ffff:ffff
642710:3f0::/282710:3ff:ffff:ffff:ffff:ffff:ffff:ffff
652710:400::/282710:40f:ffff:ffff:ffff:ffff:ffff:ffff
662710:410::/282710:41f:ffff:ffff:ffff:ffff:ffff:ffff
672710:420::/282710:42f:ffff:ffff:ffff:ffff:ffff:ffff
682710:430::/282710:43f:ffff:ffff:ffff:ffff:ffff:ffff
692710:440::/282710:44f:ffff:ffff:ffff:ffff:ffff:ffff
702710:450::/282710:45f:ffff:ffff:ffff:ffff:ffff:ffff
712710:460::/282710:46f:ffff:ffff:ffff:ffff:ffff:ffff
722710:470::/282710:47f:ffff:ffff:ffff:ffff:ffff:ffff
732710:480::/282710:48f:ffff:ffff:ffff:ffff:ffff:ffff
742710:490::/282710:49f:ffff:ffff:ffff:ffff:ffff:ffff
752710:4a0::/282710:4af:ffff:ffff:ffff:ffff:ffff:ffff
762710:4b0::/282710:4bf:ffff:ffff:ffff:ffff:ffff:ffff
772710:4c0::/282710:4cf:ffff:ffff:ffff:ffff:ffff:ffff
782710:4d0::/282710:4df:ffff:ffff:ffff:ffff:ffff:ffff
792710:4e0::/282710:4ef:ffff:ffff:ffff:ffff:ffff:ffff
802710:4f0::/282710:4ff:ffff:ffff:ffff:ffff:ffff:ffff
812710:500::/282710:50f:ffff:ffff:ffff:ffff:ffff:ffff
822710:510::/282710:51f:ffff:ffff:ffff:ffff:ffff:ffff
832710:520::/282710:52f:ffff:ffff:ffff:ffff:ffff:ffff
842710:530::/282710:53f:ffff:ffff:ffff:ffff:ffff:ffff
852710:540::/282710:54f:ffff:ffff:ffff:ffff:ffff:ffff
862710:550::/282710:55f:ffff:ffff:ffff:ffff:ffff:ffff
872710:560::/282710:56f:ffff:ffff:ffff:ffff:ffff:ffff
882710:570::/282710:57f:ffff:ffff:ffff:ffff:ffff:ffff
892710:580::/282710:58f:ffff:ffff:ffff:ffff:ffff:ffff
902710:590::/282710:59f:ffff:ffff:ffff:ffff:ffff:ffff
912710:5a0::/282710:5af:ffff:ffff:ffff:ffff:ffff:ffff
922710:5b0::/282710:5bf:ffff:ffff:ffff:ffff:ffff:ffff
932710:5c0::/282710:5cf:ffff:ffff:ffff:ffff:ffff:ffff
942710:5d0::/282710:5df:ffff:ffff:ffff:ffff:ffff:ffff
952710:5e0::/282710:5ef:ffff:ffff:ffff:ffff:ffff:ffff
962710:5f0::/282710:5ff:ffff:ffff:ffff:ffff:ffff:ffff
972710:600::/282710:60f:ffff:ffff:ffff:ffff:ffff:ffff
982710:610::/282710:61f:ffff:ffff:ffff:ffff:ffff:ffff
992710:620::/282710:62f:ffff:ffff:ffff:ffff:ffff:ffff
1002710:630::/282710:63f:ffff:ffff:ffff:ffff:ffff:ffff
1012710:640::/282710:64f:ffff:ffff:ffff:ffff:ffff:ffff
1022710:650::/282710:65f:ffff:ffff:ffff:ffff:ffff:ffff
1032710:660::/282710:66f:ffff:ffff:ffff:ffff:ffff:ffff
1042710:670::/282710:67f:ffff:ffff:ffff:ffff:ffff:ffff
1052710:680::/282710:68f:ffff:ffff:ffff:ffff:ffff:ffff
1062710:690::/282710:69f:ffff:ffff:ffff:ffff:ffff:ffff
1072710:6a0::/282710:6af:ffff:ffff:ffff:ffff:ffff:ffff
1082710:6b0::/282710:6bf:ffff:ffff:ffff:ffff:ffff:ffff
1092710:6c0::/282710:6cf:ffff:ffff:ffff:ffff:ffff:ffff
1102710:6d0::/282710:6df:ffff:ffff:ffff:ffff:ffff:ffff
1112710:6e0::/282710:6ef:ffff:ffff:ffff:ffff:ffff:ffff
1122710:6f0::/282710:6ff:ffff:ffff:ffff:ffff:ffff:ffff
1132710:700::/282710:70f:ffff:ffff:ffff:ffff:ffff:ffff
1142710:710::/282710:71f:ffff:ffff:ffff:ffff:ffff:ffff
1152710:720::/282710:72f:ffff:ffff:ffff:ffff:ffff:ffff
1162710:730::/282710:73f:ffff:ffff:ffff:ffff:ffff:ffff
1172710:740::/282710:74f:ffff:ffff:ffff:ffff:ffff:ffff
1182710:750::/282710:75f:ffff:ffff:ffff:ffff:ffff:ffff
1192710:760::/282710:76f:ffff:ffff:ffff:ffff:ffff:ffff
1202710:770::/282710:77f:ffff:ffff:ffff:ffff:ffff:ffff
1212710:780::/282710:78f:ffff:ffff:ffff:ffff:ffff:ffff
1222710:790::/282710:79f:ffff:ffff:ffff:ffff:ffff:ffff
1232710:7a0::/282710:7af:ffff:ffff:ffff:ffff:ffff:ffff
1242710:7b0::/282710:7bf:ffff:ffff:ffff:ffff:ffff:ffff
1252710:7c0::/282710:7cf:ffff:ffff:ffff:ffff:ffff:ffff
1262710:7d0::/282710:7df:ffff:ffff:ffff:ffff:ffff:ffff
1272710:7e0::/282710:7ef:ffff:ffff:ffff:ffff:ffff:ffff
1282710:7f0::/282710:7ff:ffff:ffff:ffff:ffff:ffff:ffff
1292710:800::/282710:80f:ffff:ffff:ffff:ffff:ffff:ffff
1302710:810::/282710:81f:ffff:ffff:ffff:ffff:ffff:ffff
1312710:820::/282710:82f:ffff:ffff:ffff:ffff:ffff:ffff
1322710:830::/282710:83f:ffff:ffff:ffff:ffff:ffff:ffff
1332710:840::/282710:84f:ffff:ffff:ffff:ffff:ffff:ffff
1342710:850::/282710:85f:ffff:ffff:ffff:ffff:ffff:ffff
1352710:860::/282710:86f:ffff:ffff:ffff:ffff:ffff:ffff
1362710:870::/282710:87f:ffff:ffff:ffff:ffff:ffff:ffff
1372710:880::/282710:88f:ffff:ffff:ffff:ffff:ffff:ffff
1382710:890::/282710:89f:ffff:ffff:ffff:ffff:ffff:ffff
1392710:8a0::/282710:8af:ffff:ffff:ffff:ffff:ffff:ffff
1402710:8b0::/282710:8bf:ffff:ffff:ffff:ffff:ffff:ffff
1412710:8c0::/282710:8cf:ffff:ffff:ffff:ffff:ffff:ffff
1422710:8d0::/282710:8df:ffff:ffff:ffff:ffff:ffff:ffff
1432710:8e0::/282710:8ef:ffff:ffff:ffff:ffff:ffff:ffff
1442710:8f0::/282710:8ff:ffff:ffff:ffff:ffff:ffff:ffff
1452710:900::/282710:90f:ffff:ffff:ffff:ffff:ffff:ffff
1462710:910::/282710:91f:ffff:ffff:ffff:ffff:ffff:ffff
1472710:920::/282710:92f:ffff:ffff:ffff:ffff:ffff:ffff
1482710:930::/282710:93f:ffff:ffff:ffff:ffff:ffff:ffff
1492710:940::/282710:94f:ffff:ffff:ffff:ffff:ffff:ffff
1502710:950::/282710:95f:ffff:ffff:ffff:ffff:ffff:ffff
1512710:960::/282710:96f:ffff:ffff:ffff:ffff:ffff:ffff
1522710:970::/282710:97f:ffff:ffff:ffff:ffff:ffff:ffff
1532710:980::/282710:98f:ffff:ffff:ffff:ffff:ffff:ffff
1542710:990::/282710:99f:ffff:ffff:ffff:ffff:ffff:ffff
1552710:9a0::/282710:9af:ffff:ffff:ffff:ffff:ffff:ffff
1562710:9b0::/282710:9bf:ffff:ffff:ffff:ffff:ffff:ffff
1572710:9c0::/282710:9cf:ffff:ffff:ffff:ffff:ffff:ffff
1582710:9d0::/282710:9df:ffff:ffff:ffff:ffff:ffff:ffff
1592710:9e0::/282710:9ef:ffff:ffff:ffff:ffff:ffff:ffff
1602710:9f0::/282710:9ff:ffff:ffff:ffff:ffff:ffff:ffff
1612710:a00::/282710:a0f:ffff:ffff:ffff:ffff:ffff:ffff
1622710:a10::/282710:a1f:ffff:ffff:ffff:ffff:ffff:ffff
1632710:a20::/282710:a2f:ffff:ffff:ffff:ffff:ffff:ffff
1642710:a30::/282710:a3f:ffff:ffff:ffff:ffff:ffff:ffff
1652710:a40::/282710:a4f:ffff:ffff:ffff:ffff:ffff:ffff
1662710:a50::/282710:a5f:ffff:ffff:ffff:ffff:ffff:ffff
1672710:a60::/282710:a6f:ffff:ffff:ffff:ffff:ffff:ffff
1682710:a70::/282710:a7f:ffff:ffff:ffff:ffff:ffff:ffff
1692710:a80::/282710:a8f:ffff:ffff:ffff:ffff:ffff:ffff
1702710:a90::/282710:a9f:ffff:ffff:ffff:ffff:ffff:ffff
1712710:aa0::/282710:aaf:ffff:ffff:ffff:ffff:ffff:ffff
1722710:ab0::/282710:abf:ffff:ffff:ffff:ffff:ffff:ffff
1732710:ac0::/282710:acf:ffff:ffff:ffff:ffff:ffff:ffff
1742710:ad0::/282710:adf:ffff:ffff:ffff:ffff:ffff:ffff
1752710:ae0::/282710:aef:ffff:ffff:ffff:ffff:ffff:ffff
1762710:af0::/282710:aff:ffff:ffff:ffff:ffff:ffff:ffff
1772710:b00::/282710:b0f:ffff:ffff:ffff:ffff:ffff:ffff
1782710:b10::/282710:b1f:ffff:ffff:ffff:ffff:ffff:ffff
1792710:b20::/282710:b2f:ffff:ffff:ffff:ffff:ffff:ffff
1802710:b30::/282710:b3f:ffff:ffff:ffff:ffff:ffff:ffff
1812710:b40::/282710:b4f:ffff:ffff:ffff:ffff:ffff:ffff
1822710:b50::/282710:b5f:ffff:ffff:ffff:ffff:ffff:ffff
1832710:b60::/282710:b6f:ffff:ffff:ffff:ffff:ffff:ffff
1842710:b70::/282710:b7f:ffff:ffff:ffff:ffff:ffff:ffff
1852710:b80::/282710:b8f:ffff:ffff:ffff:ffff:ffff:ffff
1862710:b90::/282710:b9f:ffff:ffff:ffff:ffff:ffff:ffff
1872710:ba0::/282710:baf:ffff:ffff:ffff:ffff:ffff:ffff
1882710:bb0::/282710:bbf:ffff:ffff:ffff:ffff:ffff:ffff
1892710:bc0::/282710:bcf:ffff:ffff:ffff:ffff:ffff:ffff
1902710:bd0::/282710:bdf:ffff:ffff:ffff:ffff:ffff:ffff
1912710:be0::/282710:bef:ffff:ffff:ffff:ffff:ffff:ffff
1922710:bf0::/282710:bff:ffff:ffff:ffff:ffff:ffff:ffff
1932710:c00::/282710:c0f:ffff:ffff:ffff:ffff:ffff:ffff
1942710:c10::/282710:c1f:ffff:ffff:ffff:ffff:ffff:ffff
1952710:c20::/282710:c2f:ffff:ffff:ffff:ffff:ffff:ffff
1962710:c30::/282710:c3f:ffff:ffff:ffff:ffff:ffff:ffff
1972710:c40::/282710:c4f:ffff:ffff:ffff:ffff:ffff:ffff
1982710:c50::/282710:c5f:ffff:ffff:ffff:ffff:ffff:ffff
1992710:c60::/282710:c6f:ffff:ffff:ffff:ffff:ffff:ffff
2002710:c70::/282710:c7f:ffff:ffff:ffff:ffff:ffff:ffff
2012710:c80::/282710:c8f:ffff:ffff:ffff:ffff:ffff:ffff
2022710:c90::/282710:c9f:ffff:ffff:ffff:ffff:ffff:ffff
2032710:ca0::/282710:caf:ffff:ffff:ffff:ffff:ffff:ffff
2042710:cb0::/282710:cbf:ffff:ffff:ffff:ffff:ffff:ffff
2052710:cc0::/282710:ccf:ffff:ffff:ffff:ffff:ffff:ffff
2062710:cd0::/282710:cdf:ffff:ffff:ffff:ffff:ffff:ffff
2072710:ce0::/282710:cef:ffff:ffff:ffff:ffff:ffff:ffff
2082710:cf0::/282710:cff:ffff:ffff:ffff:ffff:ffff:ffff
2092710:d00::/282710:d0f:ffff:ffff:ffff:ffff:ffff:ffff
2102710:d10::/282710:d1f:ffff:ffff:ffff:ffff:ffff:ffff
2112710:d20::/282710:d2f:ffff:ffff:ffff:ffff:ffff:ffff
2122710:d30::/282710:d3f:ffff:ffff:ffff:ffff:ffff:ffff
2132710:d40::/282710:d4f:ffff:ffff:ffff:ffff:ffff:ffff
2142710:d50::/282710:d5f:ffff:ffff:ffff:ffff:ffff:ffff
2152710:d60::/282710:d6f:ffff:ffff:ffff:ffff:ffff:ffff
2162710:d70::/282710:d7f:ffff:ffff:ffff:ffff:ffff:ffff
2172710:d80::/282710:d8f:ffff:ffff:ffff:ffff:ffff:ffff
2182710:d90::/282710:d9f:ffff:ffff:ffff:ffff:ffff:ffff
2192710:da0::/282710:daf:ffff:ffff:ffff:ffff:ffff:ffff
2202710:db0::/282710:dbf:ffff:ffff:ffff:ffff:ffff:ffff
2212710:dc0::/282710:dcf:ffff:ffff:ffff:ffff:ffff:ffff
2222710:dd0::/282710:ddf:ffff:ffff:ffff:ffff:ffff:ffff
2232710:de0::/282710:def:ffff:ffff:ffff:ffff:ffff:ffff
2242710:df0::/282710:dff:ffff:ffff:ffff:ffff:ffff:ffff
2252710:e00::/282710:e0f:ffff:ffff:ffff:ffff:ffff:ffff
2262710:e10::/282710:e1f:ffff:ffff:ffff:ffff:ffff:ffff
2272710:e20::/282710:e2f:ffff:ffff:ffff:ffff:ffff:ffff
2282710:e30::/282710:e3f:ffff:ffff:ffff:ffff:ffff:ffff
2292710:e40::/282710:e4f:ffff:ffff:ffff:ffff:ffff:ffff
2302710:e50::/282710:e5f:ffff:ffff:ffff:ffff:ffff:ffff
2312710:e60::/282710:e6f:ffff:ffff:ffff:ffff:ffff:ffff
2322710:e70::/282710:e7f:ffff:ffff:ffff:ffff:ffff:ffff
2332710:e80::/282710:e8f:ffff:ffff:ffff:ffff:ffff:ffff
2342710:e90::/282710:e9f:ffff:ffff:ffff:ffff:ffff:ffff
2352710:ea0::/282710:eaf:ffff:ffff:ffff:ffff:ffff:ffff
2362710:eb0::/282710:ebf:ffff:ffff:ffff:ffff:ffff:ffff
2372710:ec0::/282710:ecf:ffff:ffff:ffff:ffff:ffff:ffff
2382710:ed0::/282710:edf:ffff:ffff:ffff:ffff:ffff:ffff
2392710:ee0::/282710:eef:ffff:ffff:ffff:ffff:ffff:ffff
2402710:ef0::/282710:eff:ffff:ffff:ffff:ffff:ffff:ffff
2412710:f00::/282710:f0f:ffff:ffff:ffff:ffff:ffff:ffff
2422710:f10::/282710:f1f:ffff:ffff:ffff:ffff:ffff:ffff
2432710:f20::/282710:f2f:ffff:ffff:ffff:ffff:ffff:ffff
2442710:f30::/282710:f3f:ffff:ffff:ffff:ffff:ffff:ffff
2452710:f40::/282710:f4f:ffff:ffff:ffff:ffff:ffff:ffff
2462710:f50::/282710:f5f:ffff:ffff:ffff:ffff:ffff:ffff
2472710:f60::/282710:f6f:ffff:ffff:ffff:ffff:ffff:ffff
2482710:f70::/282710:f7f:ffff:ffff:ffff:ffff:ffff:ffff
2492710:f80::/282710:f8f:ffff:ffff:ffff:ffff:ffff:ffff
2502710:f90::/282710:f9f:ffff:ffff:ffff:ffff:ffff:ffff
2512710:fa0::/282710:faf:ffff:ffff:ffff:ffff:ffff:ffff
2522710:fb0::/282710:fbf:ffff:ffff:ffff:ffff:ffff:ffff
2532710:fc0::/282710:fcf:ffff:ffff:ffff:ffff:ffff:ffff
2542710:fd0::/282710:fdf:ffff:ffff:ffff:ffff:ffff:ffff
2552710:fe0::/282710:fef:ffff:ffff:ffff:ffff:ffff:ffff
2562710:ff0::/282710: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.