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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
3efe::/16
First address
3efe::
Last address
3efe: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
3efe:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
e.f.e.3.ip6.arpa
Split into smaller subnets/28
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

3efe::/16 makes 4,096 subnets of /28; the first 256 are listed.

Subnets
#SubnetLast address
13efe::/283efe:f:ffff:ffff:ffff:ffff:ffff:ffff
23efe:10::/283efe:1f:ffff:ffff:ffff:ffff:ffff:ffff
33efe:20::/283efe:2f:ffff:ffff:ffff:ffff:ffff:ffff
43efe:30::/283efe:3f:ffff:ffff:ffff:ffff:ffff:ffff
53efe:40::/283efe:4f:ffff:ffff:ffff:ffff:ffff:ffff
63efe:50::/283efe:5f:ffff:ffff:ffff:ffff:ffff:ffff
73efe:60::/283efe:6f:ffff:ffff:ffff:ffff:ffff:ffff
83efe:70::/283efe:7f:ffff:ffff:ffff:ffff:ffff:ffff
93efe:80::/283efe:8f:ffff:ffff:ffff:ffff:ffff:ffff
103efe:90::/283efe:9f:ffff:ffff:ffff:ffff:ffff:ffff
113efe:a0::/283efe:af:ffff:ffff:ffff:ffff:ffff:ffff
123efe:b0::/283efe:bf:ffff:ffff:ffff:ffff:ffff:ffff
133efe:c0::/283efe:cf:ffff:ffff:ffff:ffff:ffff:ffff
143efe:d0::/283efe:df:ffff:ffff:ffff:ffff:ffff:ffff
153efe:e0::/283efe:ef:ffff:ffff:ffff:ffff:ffff:ffff
163efe:f0::/283efe:ff:ffff:ffff:ffff:ffff:ffff:ffff
173efe:100::/283efe:10f:ffff:ffff:ffff:ffff:ffff:ffff
183efe:110::/283efe:11f:ffff:ffff:ffff:ffff:ffff:ffff
193efe:120::/283efe:12f:ffff:ffff:ffff:ffff:ffff:ffff
203efe:130::/283efe:13f:ffff:ffff:ffff:ffff:ffff:ffff
213efe:140::/283efe:14f:ffff:ffff:ffff:ffff:ffff:ffff
223efe:150::/283efe:15f:ffff:ffff:ffff:ffff:ffff:ffff
233efe:160::/283efe:16f:ffff:ffff:ffff:ffff:ffff:ffff
243efe:170::/283efe:17f:ffff:ffff:ffff:ffff:ffff:ffff
253efe:180::/283efe:18f:ffff:ffff:ffff:ffff:ffff:ffff
263efe:190::/283efe:19f:ffff:ffff:ffff:ffff:ffff:ffff
273efe:1a0::/283efe:1af:ffff:ffff:ffff:ffff:ffff:ffff
283efe:1b0::/283efe:1bf:ffff:ffff:ffff:ffff:ffff:ffff
293efe:1c0::/283efe:1cf:ffff:ffff:ffff:ffff:ffff:ffff
303efe:1d0::/283efe:1df:ffff:ffff:ffff:ffff:ffff:ffff
313efe:1e0::/283efe:1ef:ffff:ffff:ffff:ffff:ffff:ffff
323efe:1f0::/283efe:1ff:ffff:ffff:ffff:ffff:ffff:ffff
333efe:200::/283efe:20f:ffff:ffff:ffff:ffff:ffff:ffff
343efe:210::/283efe:21f:ffff:ffff:ffff:ffff:ffff:ffff
353efe:220::/283efe:22f:ffff:ffff:ffff:ffff:ffff:ffff
363efe:230::/283efe:23f:ffff:ffff:ffff:ffff:ffff:ffff
373efe:240::/283efe:24f:ffff:ffff:ffff:ffff:ffff:ffff
383efe:250::/283efe:25f:ffff:ffff:ffff:ffff:ffff:ffff
393efe:260::/283efe:26f:ffff:ffff:ffff:ffff:ffff:ffff
403efe:270::/283efe:27f:ffff:ffff:ffff:ffff:ffff:ffff
413efe:280::/283efe:28f:ffff:ffff:ffff:ffff:ffff:ffff
423efe:290::/283efe:29f:ffff:ffff:ffff:ffff:ffff:ffff
433efe:2a0::/283efe:2af:ffff:ffff:ffff:ffff:ffff:ffff
443efe:2b0::/283efe:2bf:ffff:ffff:ffff:ffff:ffff:ffff
453efe:2c0::/283efe:2cf:ffff:ffff:ffff:ffff:ffff:ffff
463efe:2d0::/283efe:2df:ffff:ffff:ffff:ffff:ffff:ffff
473efe:2e0::/283efe:2ef:ffff:ffff:ffff:ffff:ffff:ffff
483efe:2f0::/283efe:2ff:ffff:ffff:ffff:ffff:ffff:ffff
493efe:300::/283efe:30f:ffff:ffff:ffff:ffff:ffff:ffff
503efe:310::/283efe:31f:ffff:ffff:ffff:ffff:ffff:ffff
513efe:320::/283efe:32f:ffff:ffff:ffff:ffff:ffff:ffff
523efe:330::/283efe:33f:ffff:ffff:ffff:ffff:ffff:ffff
533efe:340::/283efe:34f:ffff:ffff:ffff:ffff:ffff:ffff
543efe:350::/283efe:35f:ffff:ffff:ffff:ffff:ffff:ffff
553efe:360::/283efe:36f:ffff:ffff:ffff:ffff:ffff:ffff
563efe:370::/283efe:37f:ffff:ffff:ffff:ffff:ffff:ffff
573efe:380::/283efe:38f:ffff:ffff:ffff:ffff:ffff:ffff
583efe:390::/283efe:39f:ffff:ffff:ffff:ffff:ffff:ffff
593efe:3a0::/283efe:3af:ffff:ffff:ffff:ffff:ffff:ffff
603efe:3b0::/283efe:3bf:ffff:ffff:ffff:ffff:ffff:ffff
613efe:3c0::/283efe:3cf:ffff:ffff:ffff:ffff:ffff:ffff
623efe:3d0::/283efe:3df:ffff:ffff:ffff:ffff:ffff:ffff
633efe:3e0::/283efe:3ef:ffff:ffff:ffff:ffff:ffff:ffff
643efe:3f0::/283efe:3ff:ffff:ffff:ffff:ffff:ffff:ffff
653efe:400::/283efe:40f:ffff:ffff:ffff:ffff:ffff:ffff
663efe:410::/283efe:41f:ffff:ffff:ffff:ffff:ffff:ffff
673efe:420::/283efe:42f:ffff:ffff:ffff:ffff:ffff:ffff
683efe:430::/283efe:43f:ffff:ffff:ffff:ffff:ffff:ffff
693efe:440::/283efe:44f:ffff:ffff:ffff:ffff:ffff:ffff
703efe:450::/283efe:45f:ffff:ffff:ffff:ffff:ffff:ffff
713efe:460::/283efe:46f:ffff:ffff:ffff:ffff:ffff:ffff
723efe:470::/283efe:47f:ffff:ffff:ffff:ffff:ffff:ffff
733efe:480::/283efe:48f:ffff:ffff:ffff:ffff:ffff:ffff
743efe:490::/283efe:49f:ffff:ffff:ffff:ffff:ffff:ffff
753efe:4a0::/283efe:4af:ffff:ffff:ffff:ffff:ffff:ffff
763efe:4b0::/283efe:4bf:ffff:ffff:ffff:ffff:ffff:ffff
773efe:4c0::/283efe:4cf:ffff:ffff:ffff:ffff:ffff:ffff
783efe:4d0::/283efe:4df:ffff:ffff:ffff:ffff:ffff:ffff
793efe:4e0::/283efe:4ef:ffff:ffff:ffff:ffff:ffff:ffff
803efe:4f0::/283efe:4ff:ffff:ffff:ffff:ffff:ffff:ffff
813efe:500::/283efe:50f:ffff:ffff:ffff:ffff:ffff:ffff
823efe:510::/283efe:51f:ffff:ffff:ffff:ffff:ffff:ffff
833efe:520::/283efe:52f:ffff:ffff:ffff:ffff:ffff:ffff
843efe:530::/283efe:53f:ffff:ffff:ffff:ffff:ffff:ffff
853efe:540::/283efe:54f:ffff:ffff:ffff:ffff:ffff:ffff
863efe:550::/283efe:55f:ffff:ffff:ffff:ffff:ffff:ffff
873efe:560::/283efe:56f:ffff:ffff:ffff:ffff:ffff:ffff
883efe:570::/283efe:57f:ffff:ffff:ffff:ffff:ffff:ffff
893efe:580::/283efe:58f:ffff:ffff:ffff:ffff:ffff:ffff
903efe:590::/283efe:59f:ffff:ffff:ffff:ffff:ffff:ffff
913efe:5a0::/283efe:5af:ffff:ffff:ffff:ffff:ffff:ffff
923efe:5b0::/283efe:5bf:ffff:ffff:ffff:ffff:ffff:ffff
933efe:5c0::/283efe:5cf:ffff:ffff:ffff:ffff:ffff:ffff
943efe:5d0::/283efe:5df:ffff:ffff:ffff:ffff:ffff:ffff
953efe:5e0::/283efe:5ef:ffff:ffff:ffff:ffff:ffff:ffff
963efe:5f0::/283efe:5ff:ffff:ffff:ffff:ffff:ffff:ffff
973efe:600::/283efe:60f:ffff:ffff:ffff:ffff:ffff:ffff
983efe:610::/283efe:61f:ffff:ffff:ffff:ffff:ffff:ffff
993efe:620::/283efe:62f:ffff:ffff:ffff:ffff:ffff:ffff
1003efe:630::/283efe:63f:ffff:ffff:ffff:ffff:ffff:ffff
1013efe:640::/283efe:64f:ffff:ffff:ffff:ffff:ffff:ffff
1023efe:650::/283efe:65f:ffff:ffff:ffff:ffff:ffff:ffff
1033efe:660::/283efe:66f:ffff:ffff:ffff:ffff:ffff:ffff
1043efe:670::/283efe:67f:ffff:ffff:ffff:ffff:ffff:ffff
1053efe:680::/283efe:68f:ffff:ffff:ffff:ffff:ffff:ffff
1063efe:690::/283efe:69f:ffff:ffff:ffff:ffff:ffff:ffff
1073efe:6a0::/283efe:6af:ffff:ffff:ffff:ffff:ffff:ffff
1083efe:6b0::/283efe:6bf:ffff:ffff:ffff:ffff:ffff:ffff
1093efe:6c0::/283efe:6cf:ffff:ffff:ffff:ffff:ffff:ffff
1103efe:6d0::/283efe:6df:ffff:ffff:ffff:ffff:ffff:ffff
1113efe:6e0::/283efe:6ef:ffff:ffff:ffff:ffff:ffff:ffff
1123efe:6f0::/283efe:6ff:ffff:ffff:ffff:ffff:ffff:ffff
1133efe:700::/283efe:70f:ffff:ffff:ffff:ffff:ffff:ffff
1143efe:710::/283efe:71f:ffff:ffff:ffff:ffff:ffff:ffff
1153efe:720::/283efe:72f:ffff:ffff:ffff:ffff:ffff:ffff
1163efe:730::/283efe:73f:ffff:ffff:ffff:ffff:ffff:ffff
1173efe:740::/283efe:74f:ffff:ffff:ffff:ffff:ffff:ffff
1183efe:750::/283efe:75f:ffff:ffff:ffff:ffff:ffff:ffff
1193efe:760::/283efe:76f:ffff:ffff:ffff:ffff:ffff:ffff
1203efe:770::/283efe:77f:ffff:ffff:ffff:ffff:ffff:ffff
1213efe:780::/283efe:78f:ffff:ffff:ffff:ffff:ffff:ffff
1223efe:790::/283efe:79f:ffff:ffff:ffff:ffff:ffff:ffff
1233efe:7a0::/283efe:7af:ffff:ffff:ffff:ffff:ffff:ffff
1243efe:7b0::/283efe:7bf:ffff:ffff:ffff:ffff:ffff:ffff
1253efe:7c0::/283efe:7cf:ffff:ffff:ffff:ffff:ffff:ffff
1263efe:7d0::/283efe:7df:ffff:ffff:ffff:ffff:ffff:ffff
1273efe:7e0::/283efe:7ef:ffff:ffff:ffff:ffff:ffff:ffff
1283efe:7f0::/283efe:7ff:ffff:ffff:ffff:ffff:ffff:ffff
1293efe:800::/283efe:80f:ffff:ffff:ffff:ffff:ffff:ffff
1303efe:810::/283efe:81f:ffff:ffff:ffff:ffff:ffff:ffff
1313efe:820::/283efe:82f:ffff:ffff:ffff:ffff:ffff:ffff
1323efe:830::/283efe:83f:ffff:ffff:ffff:ffff:ffff:ffff
1333efe:840::/283efe:84f:ffff:ffff:ffff:ffff:ffff:ffff
1343efe:850::/283efe:85f:ffff:ffff:ffff:ffff:ffff:ffff
1353efe:860::/283efe:86f:ffff:ffff:ffff:ffff:ffff:ffff
1363efe:870::/283efe:87f:ffff:ffff:ffff:ffff:ffff:ffff
1373efe:880::/283efe:88f:ffff:ffff:ffff:ffff:ffff:ffff
1383efe:890::/283efe:89f:ffff:ffff:ffff:ffff:ffff:ffff
1393efe:8a0::/283efe:8af:ffff:ffff:ffff:ffff:ffff:ffff
1403efe:8b0::/283efe:8bf:ffff:ffff:ffff:ffff:ffff:ffff
1413efe:8c0::/283efe:8cf:ffff:ffff:ffff:ffff:ffff:ffff
1423efe:8d0::/283efe:8df:ffff:ffff:ffff:ffff:ffff:ffff
1433efe:8e0::/283efe:8ef:ffff:ffff:ffff:ffff:ffff:ffff
1443efe:8f0::/283efe:8ff:ffff:ffff:ffff:ffff:ffff:ffff
1453efe:900::/283efe:90f:ffff:ffff:ffff:ffff:ffff:ffff
1463efe:910::/283efe:91f:ffff:ffff:ffff:ffff:ffff:ffff
1473efe:920::/283efe:92f:ffff:ffff:ffff:ffff:ffff:ffff
1483efe:930::/283efe:93f:ffff:ffff:ffff:ffff:ffff:ffff
1493efe:940::/283efe:94f:ffff:ffff:ffff:ffff:ffff:ffff
1503efe:950::/283efe:95f:ffff:ffff:ffff:ffff:ffff:ffff
1513efe:960::/283efe:96f:ffff:ffff:ffff:ffff:ffff:ffff
1523efe:970::/283efe:97f:ffff:ffff:ffff:ffff:ffff:ffff
1533efe:980::/283efe:98f:ffff:ffff:ffff:ffff:ffff:ffff
1543efe:990::/283efe:99f:ffff:ffff:ffff:ffff:ffff:ffff
1553efe:9a0::/283efe:9af:ffff:ffff:ffff:ffff:ffff:ffff
1563efe:9b0::/283efe:9bf:ffff:ffff:ffff:ffff:ffff:ffff
1573efe:9c0::/283efe:9cf:ffff:ffff:ffff:ffff:ffff:ffff
1583efe:9d0::/283efe:9df:ffff:ffff:ffff:ffff:ffff:ffff
1593efe:9e0::/283efe:9ef:ffff:ffff:ffff:ffff:ffff:ffff
1603efe:9f0::/283efe:9ff:ffff:ffff:ffff:ffff:ffff:ffff
1613efe:a00::/283efe:a0f:ffff:ffff:ffff:ffff:ffff:ffff
1623efe:a10::/283efe:a1f:ffff:ffff:ffff:ffff:ffff:ffff
1633efe:a20::/283efe:a2f:ffff:ffff:ffff:ffff:ffff:ffff
1643efe:a30::/283efe:a3f:ffff:ffff:ffff:ffff:ffff:ffff
1653efe:a40::/283efe:a4f:ffff:ffff:ffff:ffff:ffff:ffff
1663efe:a50::/283efe:a5f:ffff:ffff:ffff:ffff:ffff:ffff
1673efe:a60::/283efe:a6f:ffff:ffff:ffff:ffff:ffff:ffff
1683efe:a70::/283efe:a7f:ffff:ffff:ffff:ffff:ffff:ffff
1693efe:a80::/283efe:a8f:ffff:ffff:ffff:ffff:ffff:ffff
1703efe:a90::/283efe:a9f:ffff:ffff:ffff:ffff:ffff:ffff
1713efe:aa0::/283efe:aaf:ffff:ffff:ffff:ffff:ffff:ffff
1723efe:ab0::/283efe:abf:ffff:ffff:ffff:ffff:ffff:ffff
1733efe:ac0::/283efe:acf:ffff:ffff:ffff:ffff:ffff:ffff
1743efe:ad0::/283efe:adf:ffff:ffff:ffff:ffff:ffff:ffff
1753efe:ae0::/283efe:aef:ffff:ffff:ffff:ffff:ffff:ffff
1763efe:af0::/283efe:aff:ffff:ffff:ffff:ffff:ffff:ffff
1773efe:b00::/283efe:b0f:ffff:ffff:ffff:ffff:ffff:ffff
1783efe:b10::/283efe:b1f:ffff:ffff:ffff:ffff:ffff:ffff
1793efe:b20::/283efe:b2f:ffff:ffff:ffff:ffff:ffff:ffff
1803efe:b30::/283efe:b3f:ffff:ffff:ffff:ffff:ffff:ffff
1813efe:b40::/283efe:b4f:ffff:ffff:ffff:ffff:ffff:ffff
1823efe:b50::/283efe:b5f:ffff:ffff:ffff:ffff:ffff:ffff
1833efe:b60::/283efe:b6f:ffff:ffff:ffff:ffff:ffff:ffff
1843efe:b70::/283efe:b7f:ffff:ffff:ffff:ffff:ffff:ffff
1853efe:b80::/283efe:b8f:ffff:ffff:ffff:ffff:ffff:ffff
1863efe:b90::/283efe:b9f:ffff:ffff:ffff:ffff:ffff:ffff
1873efe:ba0::/283efe:baf:ffff:ffff:ffff:ffff:ffff:ffff
1883efe:bb0::/283efe:bbf:ffff:ffff:ffff:ffff:ffff:ffff
1893efe:bc0::/283efe:bcf:ffff:ffff:ffff:ffff:ffff:ffff
1903efe:bd0::/283efe:bdf:ffff:ffff:ffff:ffff:ffff:ffff
1913efe:be0::/283efe:bef:ffff:ffff:ffff:ffff:ffff:ffff
1923efe:bf0::/283efe:bff:ffff:ffff:ffff:ffff:ffff:ffff
1933efe:c00::/283efe:c0f:ffff:ffff:ffff:ffff:ffff:ffff
1943efe:c10::/283efe:c1f:ffff:ffff:ffff:ffff:ffff:ffff
1953efe:c20::/283efe:c2f:ffff:ffff:ffff:ffff:ffff:ffff
1963efe:c30::/283efe:c3f:ffff:ffff:ffff:ffff:ffff:ffff
1973efe:c40::/283efe:c4f:ffff:ffff:ffff:ffff:ffff:ffff
1983efe:c50::/283efe:c5f:ffff:ffff:ffff:ffff:ffff:ffff
1993efe:c60::/283efe:c6f:ffff:ffff:ffff:ffff:ffff:ffff
2003efe:c70::/283efe:c7f:ffff:ffff:ffff:ffff:ffff:ffff
2013efe:c80::/283efe:c8f:ffff:ffff:ffff:ffff:ffff:ffff
2023efe:c90::/283efe:c9f:ffff:ffff:ffff:ffff:ffff:ffff
2033efe:ca0::/283efe:caf:ffff:ffff:ffff:ffff:ffff:ffff
2043efe:cb0::/283efe:cbf:ffff:ffff:ffff:ffff:ffff:ffff
2053efe:cc0::/283efe:ccf:ffff:ffff:ffff:ffff:ffff:ffff
2063efe:cd0::/283efe:cdf:ffff:ffff:ffff:ffff:ffff:ffff
2073efe:ce0::/283efe:cef:ffff:ffff:ffff:ffff:ffff:ffff
2083efe:cf0::/283efe:cff:ffff:ffff:ffff:ffff:ffff:ffff
2093efe:d00::/283efe:d0f:ffff:ffff:ffff:ffff:ffff:ffff
2103efe:d10::/283efe:d1f:ffff:ffff:ffff:ffff:ffff:ffff
2113efe:d20::/283efe:d2f:ffff:ffff:ffff:ffff:ffff:ffff
2123efe:d30::/283efe:d3f:ffff:ffff:ffff:ffff:ffff:ffff
2133efe:d40::/283efe:d4f:ffff:ffff:ffff:ffff:ffff:ffff
2143efe:d50::/283efe:d5f:ffff:ffff:ffff:ffff:ffff:ffff
2153efe:d60::/283efe:d6f:ffff:ffff:ffff:ffff:ffff:ffff
2163efe:d70::/283efe:d7f:ffff:ffff:ffff:ffff:ffff:ffff
2173efe:d80::/283efe:d8f:ffff:ffff:ffff:ffff:ffff:ffff
2183efe:d90::/283efe:d9f:ffff:ffff:ffff:ffff:ffff:ffff
2193efe:da0::/283efe:daf:ffff:ffff:ffff:ffff:ffff:ffff
2203efe:db0::/283efe:dbf:ffff:ffff:ffff:ffff:ffff:ffff
2213efe:dc0::/283efe:dcf:ffff:ffff:ffff:ffff:ffff:ffff
2223efe:dd0::/283efe:ddf:ffff:ffff:ffff:ffff:ffff:ffff
2233efe:de0::/283efe:def:ffff:ffff:ffff:ffff:ffff:ffff
2243efe:df0::/283efe:dff:ffff:ffff:ffff:ffff:ffff:ffff
2253efe:e00::/283efe:e0f:ffff:ffff:ffff:ffff:ffff:ffff
2263efe:e10::/283efe:e1f:ffff:ffff:ffff:ffff:ffff:ffff
2273efe:e20::/283efe:e2f:ffff:ffff:ffff:ffff:ffff:ffff
2283efe:e30::/283efe:e3f:ffff:ffff:ffff:ffff:ffff:ffff
2293efe:e40::/283efe:e4f:ffff:ffff:ffff:ffff:ffff:ffff
2303efe:e50::/283efe:e5f:ffff:ffff:ffff:ffff:ffff:ffff
2313efe:e60::/283efe:e6f:ffff:ffff:ffff:ffff:ffff:ffff
2323efe:e70::/283efe:e7f:ffff:ffff:ffff:ffff:ffff:ffff
2333efe:e80::/283efe:e8f:ffff:ffff:ffff:ffff:ffff:ffff
2343efe:e90::/283efe:e9f:ffff:ffff:ffff:ffff:ffff:ffff
2353efe:ea0::/283efe:eaf:ffff:ffff:ffff:ffff:ffff:ffff
2363efe:eb0::/283efe:ebf:ffff:ffff:ffff:ffff:ffff:ffff
2373efe:ec0::/283efe:ecf:ffff:ffff:ffff:ffff:ffff:ffff
2383efe:ed0::/283efe:edf:ffff:ffff:ffff:ffff:ffff:ffff
2393efe:ee0::/283efe:eef:ffff:ffff:ffff:ffff:ffff:ffff
2403efe:ef0::/283efe:eff:ffff:ffff:ffff:ffff:ffff:ffff
2413efe:f00::/283efe:f0f:ffff:ffff:ffff:ffff:ffff:ffff
2423efe:f10::/283efe:f1f:ffff:ffff:ffff:ffff:ffff:ffff
2433efe:f20::/283efe:f2f:ffff:ffff:ffff:ffff:ffff:ffff
2443efe:f30::/283efe:f3f:ffff:ffff:ffff:ffff:ffff:ffff
2453efe:f40::/283efe:f4f:ffff:ffff:ffff:ffff:ffff:ffff
2463efe:f50::/283efe:f5f:ffff:ffff:ffff:ffff:ffff:ffff
2473efe:f60::/283efe:f6f:ffff:ffff:ffff:ffff:ffff:ffff
2483efe:f70::/283efe:f7f:ffff:ffff:ffff:ffff:ffff:ffff
2493efe:f80::/283efe:f8f:ffff:ffff:ffff:ffff:ffff:ffff
2503efe:f90::/283efe:f9f:ffff:ffff:ffff:ffff:ffff:ffff
2513efe:fa0::/283efe:faf:ffff:ffff:ffff:ffff:ffff:ffff
2523efe:fb0::/283efe:fbf:ffff:ffff:ffff:ffff:ffff:ffff
2533efe:fc0::/283efe:fcf:ffff:ffff:ffff:ffff:ffff:ffff
2543efe:fd0::/283efe:fdf:ffff:ffff:ffff:ffff:ffff:ffff
2553efe:fe0::/283efe:fef:ffff:ffff:ffff:ffff:ffff:ffff
2563efe:ff0::/283efe: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.