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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
2560::/12
First address
2560::
Last address
256f: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
2560:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
6.5.2.ip6.arpa
Split into smaller subnets/28
/13 (2)/14 (4)/15 (8)/16 (16)/20 (256)/24 (4,096)/28 (65,536)

2560::/12 makes 65,536 subnets of /28; the first 256 are listed.

Subnets
#SubnetLast address
12560::/282560:f:ffff:ffff:ffff:ffff:ffff:ffff
22560:10::/282560:1f:ffff:ffff:ffff:ffff:ffff:ffff
32560:20::/282560:2f:ffff:ffff:ffff:ffff:ffff:ffff
42560:30::/282560:3f:ffff:ffff:ffff:ffff:ffff:ffff
52560:40::/282560:4f:ffff:ffff:ffff:ffff:ffff:ffff
62560:50::/282560:5f:ffff:ffff:ffff:ffff:ffff:ffff
72560:60::/282560:6f:ffff:ffff:ffff:ffff:ffff:ffff
82560:70::/282560:7f:ffff:ffff:ffff:ffff:ffff:ffff
92560:80::/282560:8f:ffff:ffff:ffff:ffff:ffff:ffff
102560:90::/282560:9f:ffff:ffff:ffff:ffff:ffff:ffff
112560:a0::/282560:af:ffff:ffff:ffff:ffff:ffff:ffff
122560:b0::/282560:bf:ffff:ffff:ffff:ffff:ffff:ffff
132560:c0::/282560:cf:ffff:ffff:ffff:ffff:ffff:ffff
142560:d0::/282560:df:ffff:ffff:ffff:ffff:ffff:ffff
152560:e0::/282560:ef:ffff:ffff:ffff:ffff:ffff:ffff
162560:f0::/282560:ff:ffff:ffff:ffff:ffff:ffff:ffff
172560:100::/282560:10f:ffff:ffff:ffff:ffff:ffff:ffff
182560:110::/282560:11f:ffff:ffff:ffff:ffff:ffff:ffff
192560:120::/282560:12f:ffff:ffff:ffff:ffff:ffff:ffff
202560:130::/282560:13f:ffff:ffff:ffff:ffff:ffff:ffff
212560:140::/282560:14f:ffff:ffff:ffff:ffff:ffff:ffff
222560:150::/282560:15f:ffff:ffff:ffff:ffff:ffff:ffff
232560:160::/282560:16f:ffff:ffff:ffff:ffff:ffff:ffff
242560:170::/282560:17f:ffff:ffff:ffff:ffff:ffff:ffff
252560:180::/282560:18f:ffff:ffff:ffff:ffff:ffff:ffff
262560:190::/282560:19f:ffff:ffff:ffff:ffff:ffff:ffff
272560:1a0::/282560:1af:ffff:ffff:ffff:ffff:ffff:ffff
282560:1b0::/282560:1bf:ffff:ffff:ffff:ffff:ffff:ffff
292560:1c0::/282560:1cf:ffff:ffff:ffff:ffff:ffff:ffff
302560:1d0::/282560:1df:ffff:ffff:ffff:ffff:ffff:ffff
312560:1e0::/282560:1ef:ffff:ffff:ffff:ffff:ffff:ffff
322560:1f0::/282560:1ff:ffff:ffff:ffff:ffff:ffff:ffff
332560:200::/282560:20f:ffff:ffff:ffff:ffff:ffff:ffff
342560:210::/282560:21f:ffff:ffff:ffff:ffff:ffff:ffff
352560:220::/282560:22f:ffff:ffff:ffff:ffff:ffff:ffff
362560:230::/282560:23f:ffff:ffff:ffff:ffff:ffff:ffff
372560:240::/282560:24f:ffff:ffff:ffff:ffff:ffff:ffff
382560:250::/282560:25f:ffff:ffff:ffff:ffff:ffff:ffff
392560:260::/282560:26f:ffff:ffff:ffff:ffff:ffff:ffff
402560:270::/282560:27f:ffff:ffff:ffff:ffff:ffff:ffff
412560:280::/282560:28f:ffff:ffff:ffff:ffff:ffff:ffff
422560:290::/282560:29f:ffff:ffff:ffff:ffff:ffff:ffff
432560:2a0::/282560:2af:ffff:ffff:ffff:ffff:ffff:ffff
442560:2b0::/282560:2bf:ffff:ffff:ffff:ffff:ffff:ffff
452560:2c0::/282560:2cf:ffff:ffff:ffff:ffff:ffff:ffff
462560:2d0::/282560:2df:ffff:ffff:ffff:ffff:ffff:ffff
472560:2e0::/282560:2ef:ffff:ffff:ffff:ffff:ffff:ffff
482560:2f0::/282560:2ff:ffff:ffff:ffff:ffff:ffff:ffff
492560:300::/282560:30f:ffff:ffff:ffff:ffff:ffff:ffff
502560:310::/282560:31f:ffff:ffff:ffff:ffff:ffff:ffff
512560:320::/282560:32f:ffff:ffff:ffff:ffff:ffff:ffff
522560:330::/282560:33f:ffff:ffff:ffff:ffff:ffff:ffff
532560:340::/282560:34f:ffff:ffff:ffff:ffff:ffff:ffff
542560:350::/282560:35f:ffff:ffff:ffff:ffff:ffff:ffff
552560:360::/282560:36f:ffff:ffff:ffff:ffff:ffff:ffff
562560:370::/282560:37f:ffff:ffff:ffff:ffff:ffff:ffff
572560:380::/282560:38f:ffff:ffff:ffff:ffff:ffff:ffff
582560:390::/282560:39f:ffff:ffff:ffff:ffff:ffff:ffff
592560:3a0::/282560:3af:ffff:ffff:ffff:ffff:ffff:ffff
602560:3b0::/282560:3bf:ffff:ffff:ffff:ffff:ffff:ffff
612560:3c0::/282560:3cf:ffff:ffff:ffff:ffff:ffff:ffff
622560:3d0::/282560:3df:ffff:ffff:ffff:ffff:ffff:ffff
632560:3e0::/282560:3ef:ffff:ffff:ffff:ffff:ffff:ffff
642560:3f0::/282560:3ff:ffff:ffff:ffff:ffff:ffff:ffff
652560:400::/282560:40f:ffff:ffff:ffff:ffff:ffff:ffff
662560:410::/282560:41f:ffff:ffff:ffff:ffff:ffff:ffff
672560:420::/282560:42f:ffff:ffff:ffff:ffff:ffff:ffff
682560:430::/282560:43f:ffff:ffff:ffff:ffff:ffff:ffff
692560:440::/282560:44f:ffff:ffff:ffff:ffff:ffff:ffff
702560:450::/282560:45f:ffff:ffff:ffff:ffff:ffff:ffff
712560:460::/282560:46f:ffff:ffff:ffff:ffff:ffff:ffff
722560:470::/282560:47f:ffff:ffff:ffff:ffff:ffff:ffff
732560:480::/282560:48f:ffff:ffff:ffff:ffff:ffff:ffff
742560:490::/282560:49f:ffff:ffff:ffff:ffff:ffff:ffff
752560:4a0::/282560:4af:ffff:ffff:ffff:ffff:ffff:ffff
762560:4b0::/282560:4bf:ffff:ffff:ffff:ffff:ffff:ffff
772560:4c0::/282560:4cf:ffff:ffff:ffff:ffff:ffff:ffff
782560:4d0::/282560:4df:ffff:ffff:ffff:ffff:ffff:ffff
792560:4e0::/282560:4ef:ffff:ffff:ffff:ffff:ffff:ffff
802560:4f0::/282560:4ff:ffff:ffff:ffff:ffff:ffff:ffff
812560:500::/282560:50f:ffff:ffff:ffff:ffff:ffff:ffff
822560:510::/282560:51f:ffff:ffff:ffff:ffff:ffff:ffff
832560:520::/282560:52f:ffff:ffff:ffff:ffff:ffff:ffff
842560:530::/282560:53f:ffff:ffff:ffff:ffff:ffff:ffff
852560:540::/282560:54f:ffff:ffff:ffff:ffff:ffff:ffff
862560:550::/282560:55f:ffff:ffff:ffff:ffff:ffff:ffff
872560:560::/282560:56f:ffff:ffff:ffff:ffff:ffff:ffff
882560:570::/282560:57f:ffff:ffff:ffff:ffff:ffff:ffff
892560:580::/282560:58f:ffff:ffff:ffff:ffff:ffff:ffff
902560:590::/282560:59f:ffff:ffff:ffff:ffff:ffff:ffff
912560:5a0::/282560:5af:ffff:ffff:ffff:ffff:ffff:ffff
922560:5b0::/282560:5bf:ffff:ffff:ffff:ffff:ffff:ffff
932560:5c0::/282560:5cf:ffff:ffff:ffff:ffff:ffff:ffff
942560:5d0::/282560:5df:ffff:ffff:ffff:ffff:ffff:ffff
952560:5e0::/282560:5ef:ffff:ffff:ffff:ffff:ffff:ffff
962560:5f0::/282560:5ff:ffff:ffff:ffff:ffff:ffff:ffff
972560:600::/282560:60f:ffff:ffff:ffff:ffff:ffff:ffff
982560:610::/282560:61f:ffff:ffff:ffff:ffff:ffff:ffff
992560:620::/282560:62f:ffff:ffff:ffff:ffff:ffff:ffff
1002560:630::/282560:63f:ffff:ffff:ffff:ffff:ffff:ffff
1012560:640::/282560:64f:ffff:ffff:ffff:ffff:ffff:ffff
1022560:650::/282560:65f:ffff:ffff:ffff:ffff:ffff:ffff
1032560:660::/282560:66f:ffff:ffff:ffff:ffff:ffff:ffff
1042560:670::/282560:67f:ffff:ffff:ffff:ffff:ffff:ffff
1052560:680::/282560:68f:ffff:ffff:ffff:ffff:ffff:ffff
1062560:690::/282560:69f:ffff:ffff:ffff:ffff:ffff:ffff
1072560:6a0::/282560:6af:ffff:ffff:ffff:ffff:ffff:ffff
1082560:6b0::/282560:6bf:ffff:ffff:ffff:ffff:ffff:ffff
1092560:6c0::/282560:6cf:ffff:ffff:ffff:ffff:ffff:ffff
1102560:6d0::/282560:6df:ffff:ffff:ffff:ffff:ffff:ffff
1112560:6e0::/282560:6ef:ffff:ffff:ffff:ffff:ffff:ffff
1122560:6f0::/282560:6ff:ffff:ffff:ffff:ffff:ffff:ffff
1132560:700::/282560:70f:ffff:ffff:ffff:ffff:ffff:ffff
1142560:710::/282560:71f:ffff:ffff:ffff:ffff:ffff:ffff
1152560:720::/282560:72f:ffff:ffff:ffff:ffff:ffff:ffff
1162560:730::/282560:73f:ffff:ffff:ffff:ffff:ffff:ffff
1172560:740::/282560:74f:ffff:ffff:ffff:ffff:ffff:ffff
1182560:750::/282560:75f:ffff:ffff:ffff:ffff:ffff:ffff
1192560:760::/282560:76f:ffff:ffff:ffff:ffff:ffff:ffff
1202560:770::/282560:77f:ffff:ffff:ffff:ffff:ffff:ffff
1212560:780::/282560:78f:ffff:ffff:ffff:ffff:ffff:ffff
1222560:790::/282560:79f:ffff:ffff:ffff:ffff:ffff:ffff
1232560:7a0::/282560:7af:ffff:ffff:ffff:ffff:ffff:ffff
1242560:7b0::/282560:7bf:ffff:ffff:ffff:ffff:ffff:ffff
1252560:7c0::/282560:7cf:ffff:ffff:ffff:ffff:ffff:ffff
1262560:7d0::/282560:7df:ffff:ffff:ffff:ffff:ffff:ffff
1272560:7e0::/282560:7ef:ffff:ffff:ffff:ffff:ffff:ffff
1282560:7f0::/282560:7ff:ffff:ffff:ffff:ffff:ffff:ffff
1292560:800::/282560:80f:ffff:ffff:ffff:ffff:ffff:ffff
1302560:810::/282560:81f:ffff:ffff:ffff:ffff:ffff:ffff
1312560:820::/282560:82f:ffff:ffff:ffff:ffff:ffff:ffff
1322560:830::/282560:83f:ffff:ffff:ffff:ffff:ffff:ffff
1332560:840::/282560:84f:ffff:ffff:ffff:ffff:ffff:ffff
1342560:850::/282560:85f:ffff:ffff:ffff:ffff:ffff:ffff
1352560:860::/282560:86f:ffff:ffff:ffff:ffff:ffff:ffff
1362560:870::/282560:87f:ffff:ffff:ffff:ffff:ffff:ffff
1372560:880::/282560:88f:ffff:ffff:ffff:ffff:ffff:ffff
1382560:890::/282560:89f:ffff:ffff:ffff:ffff:ffff:ffff
1392560:8a0::/282560:8af:ffff:ffff:ffff:ffff:ffff:ffff
1402560:8b0::/282560:8bf:ffff:ffff:ffff:ffff:ffff:ffff
1412560:8c0::/282560:8cf:ffff:ffff:ffff:ffff:ffff:ffff
1422560:8d0::/282560:8df:ffff:ffff:ffff:ffff:ffff:ffff
1432560:8e0::/282560:8ef:ffff:ffff:ffff:ffff:ffff:ffff
1442560:8f0::/282560:8ff:ffff:ffff:ffff:ffff:ffff:ffff
1452560:900::/282560:90f:ffff:ffff:ffff:ffff:ffff:ffff
1462560:910::/282560:91f:ffff:ffff:ffff:ffff:ffff:ffff
1472560:920::/282560:92f:ffff:ffff:ffff:ffff:ffff:ffff
1482560:930::/282560:93f:ffff:ffff:ffff:ffff:ffff:ffff
1492560:940::/282560:94f:ffff:ffff:ffff:ffff:ffff:ffff
1502560:950::/282560:95f:ffff:ffff:ffff:ffff:ffff:ffff
1512560:960::/282560:96f:ffff:ffff:ffff:ffff:ffff:ffff
1522560:970::/282560:97f:ffff:ffff:ffff:ffff:ffff:ffff
1532560:980::/282560:98f:ffff:ffff:ffff:ffff:ffff:ffff
1542560:990::/282560:99f:ffff:ffff:ffff:ffff:ffff:ffff
1552560:9a0::/282560:9af:ffff:ffff:ffff:ffff:ffff:ffff
1562560:9b0::/282560:9bf:ffff:ffff:ffff:ffff:ffff:ffff
1572560:9c0::/282560:9cf:ffff:ffff:ffff:ffff:ffff:ffff
1582560:9d0::/282560:9df:ffff:ffff:ffff:ffff:ffff:ffff
1592560:9e0::/282560:9ef:ffff:ffff:ffff:ffff:ffff:ffff
1602560:9f0::/282560:9ff:ffff:ffff:ffff:ffff:ffff:ffff
1612560:a00::/282560:a0f:ffff:ffff:ffff:ffff:ffff:ffff
1622560:a10::/282560:a1f:ffff:ffff:ffff:ffff:ffff:ffff
1632560:a20::/282560:a2f:ffff:ffff:ffff:ffff:ffff:ffff
1642560:a30::/282560:a3f:ffff:ffff:ffff:ffff:ffff:ffff
1652560:a40::/282560:a4f:ffff:ffff:ffff:ffff:ffff:ffff
1662560:a50::/282560:a5f:ffff:ffff:ffff:ffff:ffff:ffff
1672560:a60::/282560:a6f:ffff:ffff:ffff:ffff:ffff:ffff
1682560:a70::/282560:a7f:ffff:ffff:ffff:ffff:ffff:ffff
1692560:a80::/282560:a8f:ffff:ffff:ffff:ffff:ffff:ffff
1702560:a90::/282560:a9f:ffff:ffff:ffff:ffff:ffff:ffff
1712560:aa0::/282560:aaf:ffff:ffff:ffff:ffff:ffff:ffff
1722560:ab0::/282560:abf:ffff:ffff:ffff:ffff:ffff:ffff
1732560:ac0::/282560:acf:ffff:ffff:ffff:ffff:ffff:ffff
1742560:ad0::/282560:adf:ffff:ffff:ffff:ffff:ffff:ffff
1752560:ae0::/282560:aef:ffff:ffff:ffff:ffff:ffff:ffff
1762560:af0::/282560:aff:ffff:ffff:ffff:ffff:ffff:ffff
1772560:b00::/282560:b0f:ffff:ffff:ffff:ffff:ffff:ffff
1782560:b10::/282560:b1f:ffff:ffff:ffff:ffff:ffff:ffff
1792560:b20::/282560:b2f:ffff:ffff:ffff:ffff:ffff:ffff
1802560:b30::/282560:b3f:ffff:ffff:ffff:ffff:ffff:ffff
1812560:b40::/282560:b4f:ffff:ffff:ffff:ffff:ffff:ffff
1822560:b50::/282560:b5f:ffff:ffff:ffff:ffff:ffff:ffff
1832560:b60::/282560:b6f:ffff:ffff:ffff:ffff:ffff:ffff
1842560:b70::/282560:b7f:ffff:ffff:ffff:ffff:ffff:ffff
1852560:b80::/282560:b8f:ffff:ffff:ffff:ffff:ffff:ffff
1862560:b90::/282560:b9f:ffff:ffff:ffff:ffff:ffff:ffff
1872560:ba0::/282560:baf:ffff:ffff:ffff:ffff:ffff:ffff
1882560:bb0::/282560:bbf:ffff:ffff:ffff:ffff:ffff:ffff
1892560:bc0::/282560:bcf:ffff:ffff:ffff:ffff:ffff:ffff
1902560:bd0::/282560:bdf:ffff:ffff:ffff:ffff:ffff:ffff
1912560:be0::/282560:bef:ffff:ffff:ffff:ffff:ffff:ffff
1922560:bf0::/282560:bff:ffff:ffff:ffff:ffff:ffff:ffff
1932560:c00::/282560:c0f:ffff:ffff:ffff:ffff:ffff:ffff
1942560:c10::/282560:c1f:ffff:ffff:ffff:ffff:ffff:ffff
1952560:c20::/282560:c2f:ffff:ffff:ffff:ffff:ffff:ffff
1962560:c30::/282560:c3f:ffff:ffff:ffff:ffff:ffff:ffff
1972560:c40::/282560:c4f:ffff:ffff:ffff:ffff:ffff:ffff
1982560:c50::/282560:c5f:ffff:ffff:ffff:ffff:ffff:ffff
1992560:c60::/282560:c6f:ffff:ffff:ffff:ffff:ffff:ffff
2002560:c70::/282560:c7f:ffff:ffff:ffff:ffff:ffff:ffff
2012560:c80::/282560:c8f:ffff:ffff:ffff:ffff:ffff:ffff
2022560:c90::/282560:c9f:ffff:ffff:ffff:ffff:ffff:ffff
2032560:ca0::/282560:caf:ffff:ffff:ffff:ffff:ffff:ffff
2042560:cb0::/282560:cbf:ffff:ffff:ffff:ffff:ffff:ffff
2052560:cc0::/282560:ccf:ffff:ffff:ffff:ffff:ffff:ffff
2062560:cd0::/282560:cdf:ffff:ffff:ffff:ffff:ffff:ffff
2072560:ce0::/282560:cef:ffff:ffff:ffff:ffff:ffff:ffff
2082560:cf0::/282560:cff:ffff:ffff:ffff:ffff:ffff:ffff
2092560:d00::/282560:d0f:ffff:ffff:ffff:ffff:ffff:ffff
2102560:d10::/282560:d1f:ffff:ffff:ffff:ffff:ffff:ffff
2112560:d20::/282560:d2f:ffff:ffff:ffff:ffff:ffff:ffff
2122560:d30::/282560:d3f:ffff:ffff:ffff:ffff:ffff:ffff
2132560:d40::/282560:d4f:ffff:ffff:ffff:ffff:ffff:ffff
2142560:d50::/282560:d5f:ffff:ffff:ffff:ffff:ffff:ffff
2152560:d60::/282560:d6f:ffff:ffff:ffff:ffff:ffff:ffff
2162560:d70::/282560:d7f:ffff:ffff:ffff:ffff:ffff:ffff
2172560:d80::/282560:d8f:ffff:ffff:ffff:ffff:ffff:ffff
2182560:d90::/282560:d9f:ffff:ffff:ffff:ffff:ffff:ffff
2192560:da0::/282560:daf:ffff:ffff:ffff:ffff:ffff:ffff
2202560:db0::/282560:dbf:ffff:ffff:ffff:ffff:ffff:ffff
2212560:dc0::/282560:dcf:ffff:ffff:ffff:ffff:ffff:ffff
2222560:dd0::/282560:ddf:ffff:ffff:ffff:ffff:ffff:ffff
2232560:de0::/282560:def:ffff:ffff:ffff:ffff:ffff:ffff
2242560:df0::/282560:dff:ffff:ffff:ffff:ffff:ffff:ffff
2252560:e00::/282560:e0f:ffff:ffff:ffff:ffff:ffff:ffff
2262560:e10::/282560:e1f:ffff:ffff:ffff:ffff:ffff:ffff
2272560:e20::/282560:e2f:ffff:ffff:ffff:ffff:ffff:ffff
2282560:e30::/282560:e3f:ffff:ffff:ffff:ffff:ffff:ffff
2292560:e40::/282560:e4f:ffff:ffff:ffff:ffff:ffff:ffff
2302560:e50::/282560:e5f:ffff:ffff:ffff:ffff:ffff:ffff
2312560:e60::/282560:e6f:ffff:ffff:ffff:ffff:ffff:ffff
2322560:e70::/282560:e7f:ffff:ffff:ffff:ffff:ffff:ffff
2332560:e80::/282560:e8f:ffff:ffff:ffff:ffff:ffff:ffff
2342560:e90::/282560:e9f:ffff:ffff:ffff:ffff:ffff:ffff
2352560:ea0::/282560:eaf:ffff:ffff:ffff:ffff:ffff:ffff
2362560:eb0::/282560:ebf:ffff:ffff:ffff:ffff:ffff:ffff
2372560:ec0::/282560:ecf:ffff:ffff:ffff:ffff:ffff:ffff
2382560:ed0::/282560:edf:ffff:ffff:ffff:ffff:ffff:ffff
2392560:ee0::/282560:eef:ffff:ffff:ffff:ffff:ffff:ffff
2402560:ef0::/282560:eff:ffff:ffff:ffff:ffff:ffff:ffff
2412560:f00::/282560:f0f:ffff:ffff:ffff:ffff:ffff:ffff
2422560:f10::/282560:f1f:ffff:ffff:ffff:ffff:ffff:ffff
2432560:f20::/282560:f2f:ffff:ffff:ffff:ffff:ffff:ffff
2442560:f30::/282560:f3f:ffff:ffff:ffff:ffff:ffff:ffff
2452560:f40::/282560:f4f:ffff:ffff:ffff:ffff:ffff:ffff
2462560:f50::/282560:f5f:ffff:ffff:ffff:ffff:ffff:ffff
2472560:f60::/282560:f6f:ffff:ffff:ffff:ffff:ffff:ffff
2482560:f70::/282560:f7f:ffff:ffff:ffff:ffff:ffff:ffff
2492560:f80::/282560:f8f:ffff:ffff:ffff:ffff:ffff:ffff
2502560:f90::/282560:f9f:ffff:ffff:ffff:ffff:ffff:ffff
2512560:fa0::/282560:faf:ffff:ffff:ffff:ffff:ffff:ffff
2522560:fb0::/282560:fbf:ffff:ffff:ffff:ffff:ffff:ffff
2532560:fc0::/282560:fcf:ffff:ffff:ffff:ffff:ffff:ffff
2542560:fd0::/282560:fdf:ffff:ffff:ffff:ffff:ffff:ffff
2552560:fe0::/282560:fef:ffff:ffff:ffff:ffff:ffff:ffff
2562560:ff0::/282560: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.