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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/16
Addresses2^112
/64 networks2^48
Network
2048::/16
First address
2048::
Last address
2048:ffff:ffff:ffff:ffff:ffff:ffff:ffff
Addresses
5,192,296,858,534,827,628,530,496,329,220,096 (2^112)
/64 networks (LANs)
281,474,976,710,656 (2^48)
Full form
2048:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
8.4.0.2.ip6.arpa
Split into smaller subnets/28
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

2048::/16 makes 4,096 subnets of /28; the first 256 are listed.

Subnets
#SubnetLast address
12048::/282048:f:ffff:ffff:ffff:ffff:ffff:ffff
22048:10::/282048:1f:ffff:ffff:ffff:ffff:ffff:ffff
32048:20::/282048:2f:ffff:ffff:ffff:ffff:ffff:ffff
42048:30::/282048:3f:ffff:ffff:ffff:ffff:ffff:ffff
52048:40::/282048:4f:ffff:ffff:ffff:ffff:ffff:ffff
62048:50::/282048:5f:ffff:ffff:ffff:ffff:ffff:ffff
72048:60::/282048:6f:ffff:ffff:ffff:ffff:ffff:ffff
82048:70::/282048:7f:ffff:ffff:ffff:ffff:ffff:ffff
92048:80::/282048:8f:ffff:ffff:ffff:ffff:ffff:ffff
102048:90::/282048:9f:ffff:ffff:ffff:ffff:ffff:ffff
112048:a0::/282048:af:ffff:ffff:ffff:ffff:ffff:ffff
122048:b0::/282048:bf:ffff:ffff:ffff:ffff:ffff:ffff
132048:c0::/282048:cf:ffff:ffff:ffff:ffff:ffff:ffff
142048:d0::/282048:df:ffff:ffff:ffff:ffff:ffff:ffff
152048:e0::/282048:ef:ffff:ffff:ffff:ffff:ffff:ffff
162048:f0::/282048:ff:ffff:ffff:ffff:ffff:ffff:ffff
172048:100::/282048:10f:ffff:ffff:ffff:ffff:ffff:ffff
182048:110::/282048:11f:ffff:ffff:ffff:ffff:ffff:ffff
192048:120::/282048:12f:ffff:ffff:ffff:ffff:ffff:ffff
202048:130::/282048:13f:ffff:ffff:ffff:ffff:ffff:ffff
212048:140::/282048:14f:ffff:ffff:ffff:ffff:ffff:ffff
222048:150::/282048:15f:ffff:ffff:ffff:ffff:ffff:ffff
232048:160::/282048:16f:ffff:ffff:ffff:ffff:ffff:ffff
242048:170::/282048:17f:ffff:ffff:ffff:ffff:ffff:ffff
252048:180::/282048:18f:ffff:ffff:ffff:ffff:ffff:ffff
262048:190::/282048:19f:ffff:ffff:ffff:ffff:ffff:ffff
272048:1a0::/282048:1af:ffff:ffff:ffff:ffff:ffff:ffff
282048:1b0::/282048:1bf:ffff:ffff:ffff:ffff:ffff:ffff
292048:1c0::/282048:1cf:ffff:ffff:ffff:ffff:ffff:ffff
302048:1d0::/282048:1df:ffff:ffff:ffff:ffff:ffff:ffff
312048:1e0::/282048:1ef:ffff:ffff:ffff:ffff:ffff:ffff
322048:1f0::/282048:1ff:ffff:ffff:ffff:ffff:ffff:ffff
332048:200::/282048:20f:ffff:ffff:ffff:ffff:ffff:ffff
342048:210::/282048:21f:ffff:ffff:ffff:ffff:ffff:ffff
352048:220::/282048:22f:ffff:ffff:ffff:ffff:ffff:ffff
362048:230::/282048:23f:ffff:ffff:ffff:ffff:ffff:ffff
372048:240::/282048:24f:ffff:ffff:ffff:ffff:ffff:ffff
382048:250::/282048:25f:ffff:ffff:ffff:ffff:ffff:ffff
392048:260::/282048:26f:ffff:ffff:ffff:ffff:ffff:ffff
402048:270::/282048:27f:ffff:ffff:ffff:ffff:ffff:ffff
412048:280::/282048:28f:ffff:ffff:ffff:ffff:ffff:ffff
422048:290::/282048:29f:ffff:ffff:ffff:ffff:ffff:ffff
432048:2a0::/282048:2af:ffff:ffff:ffff:ffff:ffff:ffff
442048:2b0::/282048:2bf:ffff:ffff:ffff:ffff:ffff:ffff
452048:2c0::/282048:2cf:ffff:ffff:ffff:ffff:ffff:ffff
462048:2d0::/282048:2df:ffff:ffff:ffff:ffff:ffff:ffff
472048:2e0::/282048:2ef:ffff:ffff:ffff:ffff:ffff:ffff
482048:2f0::/282048:2ff:ffff:ffff:ffff:ffff:ffff:ffff
492048:300::/282048:30f:ffff:ffff:ffff:ffff:ffff:ffff
502048:310::/282048:31f:ffff:ffff:ffff:ffff:ffff:ffff
512048:320::/282048:32f:ffff:ffff:ffff:ffff:ffff:ffff
522048:330::/282048:33f:ffff:ffff:ffff:ffff:ffff:ffff
532048:340::/282048:34f:ffff:ffff:ffff:ffff:ffff:ffff
542048:350::/282048:35f:ffff:ffff:ffff:ffff:ffff:ffff
552048:360::/282048:36f:ffff:ffff:ffff:ffff:ffff:ffff
562048:370::/282048:37f:ffff:ffff:ffff:ffff:ffff:ffff
572048:380::/282048:38f:ffff:ffff:ffff:ffff:ffff:ffff
582048:390::/282048:39f:ffff:ffff:ffff:ffff:ffff:ffff
592048:3a0::/282048:3af:ffff:ffff:ffff:ffff:ffff:ffff
602048:3b0::/282048:3bf:ffff:ffff:ffff:ffff:ffff:ffff
612048:3c0::/282048:3cf:ffff:ffff:ffff:ffff:ffff:ffff
622048:3d0::/282048:3df:ffff:ffff:ffff:ffff:ffff:ffff
632048:3e0::/282048:3ef:ffff:ffff:ffff:ffff:ffff:ffff
642048:3f0::/282048:3ff:ffff:ffff:ffff:ffff:ffff:ffff
652048:400::/282048:40f:ffff:ffff:ffff:ffff:ffff:ffff
662048:410::/282048:41f:ffff:ffff:ffff:ffff:ffff:ffff
672048:420::/282048:42f:ffff:ffff:ffff:ffff:ffff:ffff
682048:430::/282048:43f:ffff:ffff:ffff:ffff:ffff:ffff
692048:440::/282048:44f:ffff:ffff:ffff:ffff:ffff:ffff
702048:450::/282048:45f:ffff:ffff:ffff:ffff:ffff:ffff
712048:460::/282048:46f:ffff:ffff:ffff:ffff:ffff:ffff
722048:470::/282048:47f:ffff:ffff:ffff:ffff:ffff:ffff
732048:480::/282048:48f:ffff:ffff:ffff:ffff:ffff:ffff
742048:490::/282048:49f:ffff:ffff:ffff:ffff:ffff:ffff
752048:4a0::/282048:4af:ffff:ffff:ffff:ffff:ffff:ffff
762048:4b0::/282048:4bf:ffff:ffff:ffff:ffff:ffff:ffff
772048:4c0::/282048:4cf:ffff:ffff:ffff:ffff:ffff:ffff
782048:4d0::/282048:4df:ffff:ffff:ffff:ffff:ffff:ffff
792048:4e0::/282048:4ef:ffff:ffff:ffff:ffff:ffff:ffff
802048:4f0::/282048:4ff:ffff:ffff:ffff:ffff:ffff:ffff
812048:500::/282048:50f:ffff:ffff:ffff:ffff:ffff:ffff
822048:510::/282048:51f:ffff:ffff:ffff:ffff:ffff:ffff
832048:520::/282048:52f:ffff:ffff:ffff:ffff:ffff:ffff
842048:530::/282048:53f:ffff:ffff:ffff:ffff:ffff:ffff
852048:540::/282048:54f:ffff:ffff:ffff:ffff:ffff:ffff
862048:550::/282048:55f:ffff:ffff:ffff:ffff:ffff:ffff
872048:560::/282048:56f:ffff:ffff:ffff:ffff:ffff:ffff
882048:570::/282048:57f:ffff:ffff:ffff:ffff:ffff:ffff
892048:580::/282048:58f:ffff:ffff:ffff:ffff:ffff:ffff
902048:590::/282048:59f:ffff:ffff:ffff:ffff:ffff:ffff
912048:5a0::/282048:5af:ffff:ffff:ffff:ffff:ffff:ffff
922048:5b0::/282048:5bf:ffff:ffff:ffff:ffff:ffff:ffff
932048:5c0::/282048:5cf:ffff:ffff:ffff:ffff:ffff:ffff
942048:5d0::/282048:5df:ffff:ffff:ffff:ffff:ffff:ffff
952048:5e0::/282048:5ef:ffff:ffff:ffff:ffff:ffff:ffff
962048:5f0::/282048:5ff:ffff:ffff:ffff:ffff:ffff:ffff
972048:600::/282048:60f:ffff:ffff:ffff:ffff:ffff:ffff
982048:610::/282048:61f:ffff:ffff:ffff:ffff:ffff:ffff
992048:620::/282048:62f:ffff:ffff:ffff:ffff:ffff:ffff
1002048:630::/282048:63f:ffff:ffff:ffff:ffff:ffff:ffff
1012048:640::/282048:64f:ffff:ffff:ffff:ffff:ffff:ffff
1022048:650::/282048:65f:ffff:ffff:ffff:ffff:ffff:ffff
1032048:660::/282048:66f:ffff:ffff:ffff:ffff:ffff:ffff
1042048:670::/282048:67f:ffff:ffff:ffff:ffff:ffff:ffff
1052048:680::/282048:68f:ffff:ffff:ffff:ffff:ffff:ffff
1062048:690::/282048:69f:ffff:ffff:ffff:ffff:ffff:ffff
1072048:6a0::/282048:6af:ffff:ffff:ffff:ffff:ffff:ffff
1082048:6b0::/282048:6bf:ffff:ffff:ffff:ffff:ffff:ffff
1092048:6c0::/282048:6cf:ffff:ffff:ffff:ffff:ffff:ffff
1102048:6d0::/282048:6df:ffff:ffff:ffff:ffff:ffff:ffff
1112048:6e0::/282048:6ef:ffff:ffff:ffff:ffff:ffff:ffff
1122048:6f0::/282048:6ff:ffff:ffff:ffff:ffff:ffff:ffff
1132048:700::/282048:70f:ffff:ffff:ffff:ffff:ffff:ffff
1142048:710::/282048:71f:ffff:ffff:ffff:ffff:ffff:ffff
1152048:720::/282048:72f:ffff:ffff:ffff:ffff:ffff:ffff
1162048:730::/282048:73f:ffff:ffff:ffff:ffff:ffff:ffff
1172048:740::/282048:74f:ffff:ffff:ffff:ffff:ffff:ffff
1182048:750::/282048:75f:ffff:ffff:ffff:ffff:ffff:ffff
1192048:760::/282048:76f:ffff:ffff:ffff:ffff:ffff:ffff
1202048:770::/282048:77f:ffff:ffff:ffff:ffff:ffff:ffff
1212048:780::/282048:78f:ffff:ffff:ffff:ffff:ffff:ffff
1222048:790::/282048:79f:ffff:ffff:ffff:ffff:ffff:ffff
1232048:7a0::/282048:7af:ffff:ffff:ffff:ffff:ffff:ffff
1242048:7b0::/282048:7bf:ffff:ffff:ffff:ffff:ffff:ffff
1252048:7c0::/282048:7cf:ffff:ffff:ffff:ffff:ffff:ffff
1262048:7d0::/282048:7df:ffff:ffff:ffff:ffff:ffff:ffff
1272048:7e0::/282048:7ef:ffff:ffff:ffff:ffff:ffff:ffff
1282048:7f0::/282048:7ff:ffff:ffff:ffff:ffff:ffff:ffff
1292048:800::/282048:80f:ffff:ffff:ffff:ffff:ffff:ffff
1302048:810::/282048:81f:ffff:ffff:ffff:ffff:ffff:ffff
1312048:820::/282048:82f:ffff:ffff:ffff:ffff:ffff:ffff
1322048:830::/282048:83f:ffff:ffff:ffff:ffff:ffff:ffff
1332048:840::/282048:84f:ffff:ffff:ffff:ffff:ffff:ffff
1342048:850::/282048:85f:ffff:ffff:ffff:ffff:ffff:ffff
1352048:860::/282048:86f:ffff:ffff:ffff:ffff:ffff:ffff
1362048:870::/282048:87f:ffff:ffff:ffff:ffff:ffff:ffff
1372048:880::/282048:88f:ffff:ffff:ffff:ffff:ffff:ffff
1382048:890::/282048:89f:ffff:ffff:ffff:ffff:ffff:ffff
1392048:8a0::/282048:8af:ffff:ffff:ffff:ffff:ffff:ffff
1402048:8b0::/282048:8bf:ffff:ffff:ffff:ffff:ffff:ffff
1412048:8c0::/282048:8cf:ffff:ffff:ffff:ffff:ffff:ffff
1422048:8d0::/282048:8df:ffff:ffff:ffff:ffff:ffff:ffff
1432048:8e0::/282048:8ef:ffff:ffff:ffff:ffff:ffff:ffff
1442048:8f0::/282048:8ff:ffff:ffff:ffff:ffff:ffff:ffff
1452048:900::/282048:90f:ffff:ffff:ffff:ffff:ffff:ffff
1462048:910::/282048:91f:ffff:ffff:ffff:ffff:ffff:ffff
1472048:920::/282048:92f:ffff:ffff:ffff:ffff:ffff:ffff
1482048:930::/282048:93f:ffff:ffff:ffff:ffff:ffff:ffff
1492048:940::/282048:94f:ffff:ffff:ffff:ffff:ffff:ffff
1502048:950::/282048:95f:ffff:ffff:ffff:ffff:ffff:ffff
1512048:960::/282048:96f:ffff:ffff:ffff:ffff:ffff:ffff
1522048:970::/282048:97f:ffff:ffff:ffff:ffff:ffff:ffff
1532048:980::/282048:98f:ffff:ffff:ffff:ffff:ffff:ffff
1542048:990::/282048:99f:ffff:ffff:ffff:ffff:ffff:ffff
1552048:9a0::/282048:9af:ffff:ffff:ffff:ffff:ffff:ffff
1562048:9b0::/282048:9bf:ffff:ffff:ffff:ffff:ffff:ffff
1572048:9c0::/282048:9cf:ffff:ffff:ffff:ffff:ffff:ffff
1582048:9d0::/282048:9df:ffff:ffff:ffff:ffff:ffff:ffff
1592048:9e0::/282048:9ef:ffff:ffff:ffff:ffff:ffff:ffff
1602048:9f0::/282048:9ff:ffff:ffff:ffff:ffff:ffff:ffff
1612048:a00::/282048:a0f:ffff:ffff:ffff:ffff:ffff:ffff
1622048:a10::/282048:a1f:ffff:ffff:ffff:ffff:ffff:ffff
1632048:a20::/282048:a2f:ffff:ffff:ffff:ffff:ffff:ffff
1642048:a30::/282048:a3f:ffff:ffff:ffff:ffff:ffff:ffff
1652048:a40::/282048:a4f:ffff:ffff:ffff:ffff:ffff:ffff
1662048:a50::/282048:a5f:ffff:ffff:ffff:ffff:ffff:ffff
1672048:a60::/282048:a6f:ffff:ffff:ffff:ffff:ffff:ffff
1682048:a70::/282048:a7f:ffff:ffff:ffff:ffff:ffff:ffff
1692048:a80::/282048:a8f:ffff:ffff:ffff:ffff:ffff:ffff
1702048:a90::/282048:a9f:ffff:ffff:ffff:ffff:ffff:ffff
1712048:aa0::/282048:aaf:ffff:ffff:ffff:ffff:ffff:ffff
1722048:ab0::/282048:abf:ffff:ffff:ffff:ffff:ffff:ffff
1732048:ac0::/282048:acf:ffff:ffff:ffff:ffff:ffff:ffff
1742048:ad0::/282048:adf:ffff:ffff:ffff:ffff:ffff:ffff
1752048:ae0::/282048:aef:ffff:ffff:ffff:ffff:ffff:ffff
1762048:af0::/282048:aff:ffff:ffff:ffff:ffff:ffff:ffff
1772048:b00::/282048:b0f:ffff:ffff:ffff:ffff:ffff:ffff
1782048:b10::/282048:b1f:ffff:ffff:ffff:ffff:ffff:ffff
1792048:b20::/282048:b2f:ffff:ffff:ffff:ffff:ffff:ffff
1802048:b30::/282048:b3f:ffff:ffff:ffff:ffff:ffff:ffff
1812048:b40::/282048:b4f:ffff:ffff:ffff:ffff:ffff:ffff
1822048:b50::/282048:b5f:ffff:ffff:ffff:ffff:ffff:ffff
1832048:b60::/282048:b6f:ffff:ffff:ffff:ffff:ffff:ffff
1842048:b70::/282048:b7f:ffff:ffff:ffff:ffff:ffff:ffff
1852048:b80::/282048:b8f:ffff:ffff:ffff:ffff:ffff:ffff
1862048:b90::/282048:b9f:ffff:ffff:ffff:ffff:ffff:ffff
1872048:ba0::/282048:baf:ffff:ffff:ffff:ffff:ffff:ffff
1882048:bb0::/282048:bbf:ffff:ffff:ffff:ffff:ffff:ffff
1892048:bc0::/282048:bcf:ffff:ffff:ffff:ffff:ffff:ffff
1902048:bd0::/282048:bdf:ffff:ffff:ffff:ffff:ffff:ffff
1912048:be0::/282048:bef:ffff:ffff:ffff:ffff:ffff:ffff
1922048:bf0::/282048:bff:ffff:ffff:ffff:ffff:ffff:ffff
1932048:c00::/282048:c0f:ffff:ffff:ffff:ffff:ffff:ffff
1942048:c10::/282048:c1f:ffff:ffff:ffff:ffff:ffff:ffff
1952048:c20::/282048:c2f:ffff:ffff:ffff:ffff:ffff:ffff
1962048:c30::/282048:c3f:ffff:ffff:ffff:ffff:ffff:ffff
1972048:c40::/282048:c4f:ffff:ffff:ffff:ffff:ffff:ffff
1982048:c50::/282048:c5f:ffff:ffff:ffff:ffff:ffff:ffff
1992048:c60::/282048:c6f:ffff:ffff:ffff:ffff:ffff:ffff
2002048:c70::/282048:c7f:ffff:ffff:ffff:ffff:ffff:ffff
2012048:c80::/282048:c8f:ffff:ffff:ffff:ffff:ffff:ffff
2022048:c90::/282048:c9f:ffff:ffff:ffff:ffff:ffff:ffff
2032048:ca0::/282048:caf:ffff:ffff:ffff:ffff:ffff:ffff
2042048:cb0::/282048:cbf:ffff:ffff:ffff:ffff:ffff:ffff
2052048:cc0::/282048:ccf:ffff:ffff:ffff:ffff:ffff:ffff
2062048:cd0::/282048:cdf:ffff:ffff:ffff:ffff:ffff:ffff
2072048:ce0::/282048:cef:ffff:ffff:ffff:ffff:ffff:ffff
2082048:cf0::/282048:cff:ffff:ffff:ffff:ffff:ffff:ffff
2092048:d00::/282048:d0f:ffff:ffff:ffff:ffff:ffff:ffff
2102048:d10::/282048:d1f:ffff:ffff:ffff:ffff:ffff:ffff
2112048:d20::/282048:d2f:ffff:ffff:ffff:ffff:ffff:ffff
2122048:d30::/282048:d3f:ffff:ffff:ffff:ffff:ffff:ffff
2132048:d40::/282048:d4f:ffff:ffff:ffff:ffff:ffff:ffff
2142048:d50::/282048:d5f:ffff:ffff:ffff:ffff:ffff:ffff
2152048:d60::/282048:d6f:ffff:ffff:ffff:ffff:ffff:ffff
2162048:d70::/282048:d7f:ffff:ffff:ffff:ffff:ffff:ffff
2172048:d80::/282048:d8f:ffff:ffff:ffff:ffff:ffff:ffff
2182048:d90::/282048:d9f:ffff:ffff:ffff:ffff:ffff:ffff
2192048:da0::/282048:daf:ffff:ffff:ffff:ffff:ffff:ffff
2202048:db0::/282048:dbf:ffff:ffff:ffff:ffff:ffff:ffff
2212048:dc0::/282048:dcf:ffff:ffff:ffff:ffff:ffff:ffff
2222048:dd0::/282048:ddf:ffff:ffff:ffff:ffff:ffff:ffff
2232048:de0::/282048:def:ffff:ffff:ffff:ffff:ffff:ffff
2242048:df0::/282048:dff:ffff:ffff:ffff:ffff:ffff:ffff
2252048:e00::/282048:e0f:ffff:ffff:ffff:ffff:ffff:ffff
2262048:e10::/282048:e1f:ffff:ffff:ffff:ffff:ffff:ffff
2272048:e20::/282048:e2f:ffff:ffff:ffff:ffff:ffff:ffff
2282048:e30::/282048:e3f:ffff:ffff:ffff:ffff:ffff:ffff
2292048:e40::/282048:e4f:ffff:ffff:ffff:ffff:ffff:ffff
2302048:e50::/282048:e5f:ffff:ffff:ffff:ffff:ffff:ffff
2312048:e60::/282048:e6f:ffff:ffff:ffff:ffff:ffff:ffff
2322048:e70::/282048:e7f:ffff:ffff:ffff:ffff:ffff:ffff
2332048:e80::/282048:e8f:ffff:ffff:ffff:ffff:ffff:ffff
2342048:e90::/282048:e9f:ffff:ffff:ffff:ffff:ffff:ffff
2352048:ea0::/282048:eaf:ffff:ffff:ffff:ffff:ffff:ffff
2362048:eb0::/282048:ebf:ffff:ffff:ffff:ffff:ffff:ffff
2372048:ec0::/282048:ecf:ffff:ffff:ffff:ffff:ffff:ffff
2382048:ed0::/282048:edf:ffff:ffff:ffff:ffff:ffff:ffff
2392048:ee0::/282048:eef:ffff:ffff:ffff:ffff:ffff:ffff
2402048:ef0::/282048:eff:ffff:ffff:ffff:ffff:ffff:ffff
2412048:f00::/282048:f0f:ffff:ffff:ffff:ffff:ffff:ffff
2422048:f10::/282048:f1f:ffff:ffff:ffff:ffff:ffff:ffff
2432048:f20::/282048:f2f:ffff:ffff:ffff:ffff:ffff:ffff
2442048:f30::/282048:f3f:ffff:ffff:ffff:ffff:ffff:ffff
2452048:f40::/282048:f4f:ffff:ffff:ffff:ffff:ffff:ffff
2462048:f50::/282048:f5f:ffff:ffff:ffff:ffff:ffff:ffff
2472048:f60::/282048:f6f:ffff:ffff:ffff:ffff:ffff:ffff
2482048:f70::/282048:f7f:ffff:ffff:ffff:ffff:ffff:ffff
2492048:f80::/282048:f8f:ffff:ffff:ffff:ffff:ffff:ffff
2502048:f90::/282048:f9f:ffff:ffff:ffff:ffff:ffff:ffff
2512048:fa0::/282048:faf:ffff:ffff:ffff:ffff:ffff:ffff
2522048:fb0::/282048:fbf:ffff:ffff:ffff:ffff:ffff:ffff
2532048:fc0::/282048:fcf:ffff:ffff:ffff:ffff:ffff:ffff
2542048:fd0::/282048:fdf:ffff:ffff:ffff:ffff:ffff:ffff
2552048:fe0::/282048:fef:ffff:ffff:ffff:ffff:ffff:ffff
2562048:ff0::/282048: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.