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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
2570::/12
First address
2570::
Last address
257f: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
2570:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
7.5.2.ip6.arpa
Split into smaller subnets/28
/13 (2)/14 (4)/15 (8)/16 (16)/20 (256)/24 (4,096)/28 (65,536)

2570::/12 makes 65,536 subnets of /28; the first 256 are listed.

Subnets
#SubnetLast address
12570::/282570:f:ffff:ffff:ffff:ffff:ffff:ffff
22570:10::/282570:1f:ffff:ffff:ffff:ffff:ffff:ffff
32570:20::/282570:2f:ffff:ffff:ffff:ffff:ffff:ffff
42570:30::/282570:3f:ffff:ffff:ffff:ffff:ffff:ffff
52570:40::/282570:4f:ffff:ffff:ffff:ffff:ffff:ffff
62570:50::/282570:5f:ffff:ffff:ffff:ffff:ffff:ffff
72570:60::/282570:6f:ffff:ffff:ffff:ffff:ffff:ffff
82570:70::/282570:7f:ffff:ffff:ffff:ffff:ffff:ffff
92570:80::/282570:8f:ffff:ffff:ffff:ffff:ffff:ffff
102570:90::/282570:9f:ffff:ffff:ffff:ffff:ffff:ffff
112570:a0::/282570:af:ffff:ffff:ffff:ffff:ffff:ffff
122570:b0::/282570:bf:ffff:ffff:ffff:ffff:ffff:ffff
132570:c0::/282570:cf:ffff:ffff:ffff:ffff:ffff:ffff
142570:d0::/282570:df:ffff:ffff:ffff:ffff:ffff:ffff
152570:e0::/282570:ef:ffff:ffff:ffff:ffff:ffff:ffff
162570:f0::/282570:ff:ffff:ffff:ffff:ffff:ffff:ffff
172570:100::/282570:10f:ffff:ffff:ffff:ffff:ffff:ffff
182570:110::/282570:11f:ffff:ffff:ffff:ffff:ffff:ffff
192570:120::/282570:12f:ffff:ffff:ffff:ffff:ffff:ffff
202570:130::/282570:13f:ffff:ffff:ffff:ffff:ffff:ffff
212570:140::/282570:14f:ffff:ffff:ffff:ffff:ffff:ffff
222570:150::/282570:15f:ffff:ffff:ffff:ffff:ffff:ffff
232570:160::/282570:16f:ffff:ffff:ffff:ffff:ffff:ffff
242570:170::/282570:17f:ffff:ffff:ffff:ffff:ffff:ffff
252570:180::/282570:18f:ffff:ffff:ffff:ffff:ffff:ffff
262570:190::/282570:19f:ffff:ffff:ffff:ffff:ffff:ffff
272570:1a0::/282570:1af:ffff:ffff:ffff:ffff:ffff:ffff
282570:1b0::/282570:1bf:ffff:ffff:ffff:ffff:ffff:ffff
292570:1c0::/282570:1cf:ffff:ffff:ffff:ffff:ffff:ffff
302570:1d0::/282570:1df:ffff:ffff:ffff:ffff:ffff:ffff
312570:1e0::/282570:1ef:ffff:ffff:ffff:ffff:ffff:ffff
322570:1f0::/282570:1ff:ffff:ffff:ffff:ffff:ffff:ffff
332570:200::/282570:20f:ffff:ffff:ffff:ffff:ffff:ffff
342570:210::/282570:21f:ffff:ffff:ffff:ffff:ffff:ffff
352570:220::/282570:22f:ffff:ffff:ffff:ffff:ffff:ffff
362570:230::/282570:23f:ffff:ffff:ffff:ffff:ffff:ffff
372570:240::/282570:24f:ffff:ffff:ffff:ffff:ffff:ffff
382570:250::/282570:25f:ffff:ffff:ffff:ffff:ffff:ffff
392570:260::/282570:26f:ffff:ffff:ffff:ffff:ffff:ffff
402570:270::/282570:27f:ffff:ffff:ffff:ffff:ffff:ffff
412570:280::/282570:28f:ffff:ffff:ffff:ffff:ffff:ffff
422570:290::/282570:29f:ffff:ffff:ffff:ffff:ffff:ffff
432570:2a0::/282570:2af:ffff:ffff:ffff:ffff:ffff:ffff
442570:2b0::/282570:2bf:ffff:ffff:ffff:ffff:ffff:ffff
452570:2c0::/282570:2cf:ffff:ffff:ffff:ffff:ffff:ffff
462570:2d0::/282570:2df:ffff:ffff:ffff:ffff:ffff:ffff
472570:2e0::/282570:2ef:ffff:ffff:ffff:ffff:ffff:ffff
482570:2f0::/282570:2ff:ffff:ffff:ffff:ffff:ffff:ffff
492570:300::/282570:30f:ffff:ffff:ffff:ffff:ffff:ffff
502570:310::/282570:31f:ffff:ffff:ffff:ffff:ffff:ffff
512570:320::/282570:32f:ffff:ffff:ffff:ffff:ffff:ffff
522570:330::/282570:33f:ffff:ffff:ffff:ffff:ffff:ffff
532570:340::/282570:34f:ffff:ffff:ffff:ffff:ffff:ffff
542570:350::/282570:35f:ffff:ffff:ffff:ffff:ffff:ffff
552570:360::/282570:36f:ffff:ffff:ffff:ffff:ffff:ffff
562570:370::/282570:37f:ffff:ffff:ffff:ffff:ffff:ffff
572570:380::/282570:38f:ffff:ffff:ffff:ffff:ffff:ffff
582570:390::/282570:39f:ffff:ffff:ffff:ffff:ffff:ffff
592570:3a0::/282570:3af:ffff:ffff:ffff:ffff:ffff:ffff
602570:3b0::/282570:3bf:ffff:ffff:ffff:ffff:ffff:ffff
612570:3c0::/282570:3cf:ffff:ffff:ffff:ffff:ffff:ffff
622570:3d0::/282570:3df:ffff:ffff:ffff:ffff:ffff:ffff
632570:3e0::/282570:3ef:ffff:ffff:ffff:ffff:ffff:ffff
642570:3f0::/282570:3ff:ffff:ffff:ffff:ffff:ffff:ffff
652570:400::/282570:40f:ffff:ffff:ffff:ffff:ffff:ffff
662570:410::/282570:41f:ffff:ffff:ffff:ffff:ffff:ffff
672570:420::/282570:42f:ffff:ffff:ffff:ffff:ffff:ffff
682570:430::/282570:43f:ffff:ffff:ffff:ffff:ffff:ffff
692570:440::/282570:44f:ffff:ffff:ffff:ffff:ffff:ffff
702570:450::/282570:45f:ffff:ffff:ffff:ffff:ffff:ffff
712570:460::/282570:46f:ffff:ffff:ffff:ffff:ffff:ffff
722570:470::/282570:47f:ffff:ffff:ffff:ffff:ffff:ffff
732570:480::/282570:48f:ffff:ffff:ffff:ffff:ffff:ffff
742570:490::/282570:49f:ffff:ffff:ffff:ffff:ffff:ffff
752570:4a0::/282570:4af:ffff:ffff:ffff:ffff:ffff:ffff
762570:4b0::/282570:4bf:ffff:ffff:ffff:ffff:ffff:ffff
772570:4c0::/282570:4cf:ffff:ffff:ffff:ffff:ffff:ffff
782570:4d0::/282570:4df:ffff:ffff:ffff:ffff:ffff:ffff
792570:4e0::/282570:4ef:ffff:ffff:ffff:ffff:ffff:ffff
802570:4f0::/282570:4ff:ffff:ffff:ffff:ffff:ffff:ffff
812570:500::/282570:50f:ffff:ffff:ffff:ffff:ffff:ffff
822570:510::/282570:51f:ffff:ffff:ffff:ffff:ffff:ffff
832570:520::/282570:52f:ffff:ffff:ffff:ffff:ffff:ffff
842570:530::/282570:53f:ffff:ffff:ffff:ffff:ffff:ffff
852570:540::/282570:54f:ffff:ffff:ffff:ffff:ffff:ffff
862570:550::/282570:55f:ffff:ffff:ffff:ffff:ffff:ffff
872570:560::/282570:56f:ffff:ffff:ffff:ffff:ffff:ffff
882570:570::/282570:57f:ffff:ffff:ffff:ffff:ffff:ffff
892570:580::/282570:58f:ffff:ffff:ffff:ffff:ffff:ffff
902570:590::/282570:59f:ffff:ffff:ffff:ffff:ffff:ffff
912570:5a0::/282570:5af:ffff:ffff:ffff:ffff:ffff:ffff
922570:5b0::/282570:5bf:ffff:ffff:ffff:ffff:ffff:ffff
932570:5c0::/282570:5cf:ffff:ffff:ffff:ffff:ffff:ffff
942570:5d0::/282570:5df:ffff:ffff:ffff:ffff:ffff:ffff
952570:5e0::/282570:5ef:ffff:ffff:ffff:ffff:ffff:ffff
962570:5f0::/282570:5ff:ffff:ffff:ffff:ffff:ffff:ffff
972570:600::/282570:60f:ffff:ffff:ffff:ffff:ffff:ffff
982570:610::/282570:61f:ffff:ffff:ffff:ffff:ffff:ffff
992570:620::/282570:62f:ffff:ffff:ffff:ffff:ffff:ffff
1002570:630::/282570:63f:ffff:ffff:ffff:ffff:ffff:ffff
1012570:640::/282570:64f:ffff:ffff:ffff:ffff:ffff:ffff
1022570:650::/282570:65f:ffff:ffff:ffff:ffff:ffff:ffff
1032570:660::/282570:66f:ffff:ffff:ffff:ffff:ffff:ffff
1042570:670::/282570:67f:ffff:ffff:ffff:ffff:ffff:ffff
1052570:680::/282570:68f:ffff:ffff:ffff:ffff:ffff:ffff
1062570:690::/282570:69f:ffff:ffff:ffff:ffff:ffff:ffff
1072570:6a0::/282570:6af:ffff:ffff:ffff:ffff:ffff:ffff
1082570:6b0::/282570:6bf:ffff:ffff:ffff:ffff:ffff:ffff
1092570:6c0::/282570:6cf:ffff:ffff:ffff:ffff:ffff:ffff
1102570:6d0::/282570:6df:ffff:ffff:ffff:ffff:ffff:ffff
1112570:6e0::/282570:6ef:ffff:ffff:ffff:ffff:ffff:ffff
1122570:6f0::/282570:6ff:ffff:ffff:ffff:ffff:ffff:ffff
1132570:700::/282570:70f:ffff:ffff:ffff:ffff:ffff:ffff
1142570:710::/282570:71f:ffff:ffff:ffff:ffff:ffff:ffff
1152570:720::/282570:72f:ffff:ffff:ffff:ffff:ffff:ffff
1162570:730::/282570:73f:ffff:ffff:ffff:ffff:ffff:ffff
1172570:740::/282570:74f:ffff:ffff:ffff:ffff:ffff:ffff
1182570:750::/282570:75f:ffff:ffff:ffff:ffff:ffff:ffff
1192570:760::/282570:76f:ffff:ffff:ffff:ffff:ffff:ffff
1202570:770::/282570:77f:ffff:ffff:ffff:ffff:ffff:ffff
1212570:780::/282570:78f:ffff:ffff:ffff:ffff:ffff:ffff
1222570:790::/282570:79f:ffff:ffff:ffff:ffff:ffff:ffff
1232570:7a0::/282570:7af:ffff:ffff:ffff:ffff:ffff:ffff
1242570:7b0::/282570:7bf:ffff:ffff:ffff:ffff:ffff:ffff
1252570:7c0::/282570:7cf:ffff:ffff:ffff:ffff:ffff:ffff
1262570:7d0::/282570:7df:ffff:ffff:ffff:ffff:ffff:ffff
1272570:7e0::/282570:7ef:ffff:ffff:ffff:ffff:ffff:ffff
1282570:7f0::/282570:7ff:ffff:ffff:ffff:ffff:ffff:ffff
1292570:800::/282570:80f:ffff:ffff:ffff:ffff:ffff:ffff
1302570:810::/282570:81f:ffff:ffff:ffff:ffff:ffff:ffff
1312570:820::/282570:82f:ffff:ffff:ffff:ffff:ffff:ffff
1322570:830::/282570:83f:ffff:ffff:ffff:ffff:ffff:ffff
1332570:840::/282570:84f:ffff:ffff:ffff:ffff:ffff:ffff
1342570:850::/282570:85f:ffff:ffff:ffff:ffff:ffff:ffff
1352570:860::/282570:86f:ffff:ffff:ffff:ffff:ffff:ffff
1362570:870::/282570:87f:ffff:ffff:ffff:ffff:ffff:ffff
1372570:880::/282570:88f:ffff:ffff:ffff:ffff:ffff:ffff
1382570:890::/282570:89f:ffff:ffff:ffff:ffff:ffff:ffff
1392570:8a0::/282570:8af:ffff:ffff:ffff:ffff:ffff:ffff
1402570:8b0::/282570:8bf:ffff:ffff:ffff:ffff:ffff:ffff
1412570:8c0::/282570:8cf:ffff:ffff:ffff:ffff:ffff:ffff
1422570:8d0::/282570:8df:ffff:ffff:ffff:ffff:ffff:ffff
1432570:8e0::/282570:8ef:ffff:ffff:ffff:ffff:ffff:ffff
1442570:8f0::/282570:8ff:ffff:ffff:ffff:ffff:ffff:ffff
1452570:900::/282570:90f:ffff:ffff:ffff:ffff:ffff:ffff
1462570:910::/282570:91f:ffff:ffff:ffff:ffff:ffff:ffff
1472570:920::/282570:92f:ffff:ffff:ffff:ffff:ffff:ffff
1482570:930::/282570:93f:ffff:ffff:ffff:ffff:ffff:ffff
1492570:940::/282570:94f:ffff:ffff:ffff:ffff:ffff:ffff
1502570:950::/282570:95f:ffff:ffff:ffff:ffff:ffff:ffff
1512570:960::/282570:96f:ffff:ffff:ffff:ffff:ffff:ffff
1522570:970::/282570:97f:ffff:ffff:ffff:ffff:ffff:ffff
1532570:980::/282570:98f:ffff:ffff:ffff:ffff:ffff:ffff
1542570:990::/282570:99f:ffff:ffff:ffff:ffff:ffff:ffff
1552570:9a0::/282570:9af:ffff:ffff:ffff:ffff:ffff:ffff
1562570:9b0::/282570:9bf:ffff:ffff:ffff:ffff:ffff:ffff
1572570:9c0::/282570:9cf:ffff:ffff:ffff:ffff:ffff:ffff
1582570:9d0::/282570:9df:ffff:ffff:ffff:ffff:ffff:ffff
1592570:9e0::/282570:9ef:ffff:ffff:ffff:ffff:ffff:ffff
1602570:9f0::/282570:9ff:ffff:ffff:ffff:ffff:ffff:ffff
1612570:a00::/282570:a0f:ffff:ffff:ffff:ffff:ffff:ffff
1622570:a10::/282570:a1f:ffff:ffff:ffff:ffff:ffff:ffff
1632570:a20::/282570:a2f:ffff:ffff:ffff:ffff:ffff:ffff
1642570:a30::/282570:a3f:ffff:ffff:ffff:ffff:ffff:ffff
1652570:a40::/282570:a4f:ffff:ffff:ffff:ffff:ffff:ffff
1662570:a50::/282570:a5f:ffff:ffff:ffff:ffff:ffff:ffff
1672570:a60::/282570:a6f:ffff:ffff:ffff:ffff:ffff:ffff
1682570:a70::/282570:a7f:ffff:ffff:ffff:ffff:ffff:ffff
1692570:a80::/282570:a8f:ffff:ffff:ffff:ffff:ffff:ffff
1702570:a90::/282570:a9f:ffff:ffff:ffff:ffff:ffff:ffff
1712570:aa0::/282570:aaf:ffff:ffff:ffff:ffff:ffff:ffff
1722570:ab0::/282570:abf:ffff:ffff:ffff:ffff:ffff:ffff
1732570:ac0::/282570:acf:ffff:ffff:ffff:ffff:ffff:ffff
1742570:ad0::/282570:adf:ffff:ffff:ffff:ffff:ffff:ffff
1752570:ae0::/282570:aef:ffff:ffff:ffff:ffff:ffff:ffff
1762570:af0::/282570:aff:ffff:ffff:ffff:ffff:ffff:ffff
1772570:b00::/282570:b0f:ffff:ffff:ffff:ffff:ffff:ffff
1782570:b10::/282570:b1f:ffff:ffff:ffff:ffff:ffff:ffff
1792570:b20::/282570:b2f:ffff:ffff:ffff:ffff:ffff:ffff
1802570:b30::/282570:b3f:ffff:ffff:ffff:ffff:ffff:ffff
1812570:b40::/282570:b4f:ffff:ffff:ffff:ffff:ffff:ffff
1822570:b50::/282570:b5f:ffff:ffff:ffff:ffff:ffff:ffff
1832570:b60::/282570:b6f:ffff:ffff:ffff:ffff:ffff:ffff
1842570:b70::/282570:b7f:ffff:ffff:ffff:ffff:ffff:ffff
1852570:b80::/282570:b8f:ffff:ffff:ffff:ffff:ffff:ffff
1862570:b90::/282570:b9f:ffff:ffff:ffff:ffff:ffff:ffff
1872570:ba0::/282570:baf:ffff:ffff:ffff:ffff:ffff:ffff
1882570:bb0::/282570:bbf:ffff:ffff:ffff:ffff:ffff:ffff
1892570:bc0::/282570:bcf:ffff:ffff:ffff:ffff:ffff:ffff
1902570:bd0::/282570:bdf:ffff:ffff:ffff:ffff:ffff:ffff
1912570:be0::/282570:bef:ffff:ffff:ffff:ffff:ffff:ffff
1922570:bf0::/282570:bff:ffff:ffff:ffff:ffff:ffff:ffff
1932570:c00::/282570:c0f:ffff:ffff:ffff:ffff:ffff:ffff
1942570:c10::/282570:c1f:ffff:ffff:ffff:ffff:ffff:ffff
1952570:c20::/282570:c2f:ffff:ffff:ffff:ffff:ffff:ffff
1962570:c30::/282570:c3f:ffff:ffff:ffff:ffff:ffff:ffff
1972570:c40::/282570:c4f:ffff:ffff:ffff:ffff:ffff:ffff
1982570:c50::/282570:c5f:ffff:ffff:ffff:ffff:ffff:ffff
1992570:c60::/282570:c6f:ffff:ffff:ffff:ffff:ffff:ffff
2002570:c70::/282570:c7f:ffff:ffff:ffff:ffff:ffff:ffff
2012570:c80::/282570:c8f:ffff:ffff:ffff:ffff:ffff:ffff
2022570:c90::/282570:c9f:ffff:ffff:ffff:ffff:ffff:ffff
2032570:ca0::/282570:caf:ffff:ffff:ffff:ffff:ffff:ffff
2042570:cb0::/282570:cbf:ffff:ffff:ffff:ffff:ffff:ffff
2052570:cc0::/282570:ccf:ffff:ffff:ffff:ffff:ffff:ffff
2062570:cd0::/282570:cdf:ffff:ffff:ffff:ffff:ffff:ffff
2072570:ce0::/282570:cef:ffff:ffff:ffff:ffff:ffff:ffff
2082570:cf0::/282570:cff:ffff:ffff:ffff:ffff:ffff:ffff
2092570:d00::/282570:d0f:ffff:ffff:ffff:ffff:ffff:ffff
2102570:d10::/282570:d1f:ffff:ffff:ffff:ffff:ffff:ffff
2112570:d20::/282570:d2f:ffff:ffff:ffff:ffff:ffff:ffff
2122570:d30::/282570:d3f:ffff:ffff:ffff:ffff:ffff:ffff
2132570:d40::/282570:d4f:ffff:ffff:ffff:ffff:ffff:ffff
2142570:d50::/282570:d5f:ffff:ffff:ffff:ffff:ffff:ffff
2152570:d60::/282570:d6f:ffff:ffff:ffff:ffff:ffff:ffff
2162570:d70::/282570:d7f:ffff:ffff:ffff:ffff:ffff:ffff
2172570:d80::/282570:d8f:ffff:ffff:ffff:ffff:ffff:ffff
2182570:d90::/282570:d9f:ffff:ffff:ffff:ffff:ffff:ffff
2192570:da0::/282570:daf:ffff:ffff:ffff:ffff:ffff:ffff
2202570:db0::/282570:dbf:ffff:ffff:ffff:ffff:ffff:ffff
2212570:dc0::/282570:dcf:ffff:ffff:ffff:ffff:ffff:ffff
2222570:dd0::/282570:ddf:ffff:ffff:ffff:ffff:ffff:ffff
2232570:de0::/282570:def:ffff:ffff:ffff:ffff:ffff:ffff
2242570:df0::/282570:dff:ffff:ffff:ffff:ffff:ffff:ffff
2252570:e00::/282570:e0f:ffff:ffff:ffff:ffff:ffff:ffff
2262570:e10::/282570:e1f:ffff:ffff:ffff:ffff:ffff:ffff
2272570:e20::/282570:e2f:ffff:ffff:ffff:ffff:ffff:ffff
2282570:e30::/282570:e3f:ffff:ffff:ffff:ffff:ffff:ffff
2292570:e40::/282570:e4f:ffff:ffff:ffff:ffff:ffff:ffff
2302570:e50::/282570:e5f:ffff:ffff:ffff:ffff:ffff:ffff
2312570:e60::/282570:e6f:ffff:ffff:ffff:ffff:ffff:ffff
2322570:e70::/282570:e7f:ffff:ffff:ffff:ffff:ffff:ffff
2332570:e80::/282570:e8f:ffff:ffff:ffff:ffff:ffff:ffff
2342570:e90::/282570:e9f:ffff:ffff:ffff:ffff:ffff:ffff
2352570:ea0::/282570:eaf:ffff:ffff:ffff:ffff:ffff:ffff
2362570:eb0::/282570:ebf:ffff:ffff:ffff:ffff:ffff:ffff
2372570:ec0::/282570:ecf:ffff:ffff:ffff:ffff:ffff:ffff
2382570:ed0::/282570:edf:ffff:ffff:ffff:ffff:ffff:ffff
2392570:ee0::/282570:eef:ffff:ffff:ffff:ffff:ffff:ffff
2402570:ef0::/282570:eff:ffff:ffff:ffff:ffff:ffff:ffff
2412570:f00::/282570:f0f:ffff:ffff:ffff:ffff:ffff:ffff
2422570:f10::/282570:f1f:ffff:ffff:ffff:ffff:ffff:ffff
2432570:f20::/282570:f2f:ffff:ffff:ffff:ffff:ffff:ffff
2442570:f30::/282570:f3f:ffff:ffff:ffff:ffff:ffff:ffff
2452570:f40::/282570:f4f:ffff:ffff:ffff:ffff:ffff:ffff
2462570:f50::/282570:f5f:ffff:ffff:ffff:ffff:ffff:ffff
2472570:f60::/282570:f6f:ffff:ffff:ffff:ffff:ffff:ffff
2482570:f70::/282570:f7f:ffff:ffff:ffff:ffff:ffff:ffff
2492570:f80::/282570:f8f:ffff:ffff:ffff:ffff:ffff:ffff
2502570:f90::/282570:f9f:ffff:ffff:ffff:ffff:ffff:ffff
2512570:fa0::/282570:faf:ffff:ffff:ffff:ffff:ffff:ffff
2522570:fb0::/282570:fbf:ffff:ffff:ffff:ffff:ffff:ffff
2532570:fc0::/282570:fcf:ffff:ffff:ffff:ffff:ffff:ffff
2542570:fd0::/282570:fdf:ffff:ffff:ffff:ffff:ffff:ffff
2552570:fe0::/282570:fef:ffff:ffff:ffff:ffff:ffff:ffff
2562570:ff0::/282570: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.