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

3aaa::/16 makes 256 subnets of /24.

Subnets
#SubnetLast address
13aaa::/243aaa:ff:ffff:ffff:ffff:ffff:ffff:ffff
23aaa:100::/243aaa:1ff:ffff:ffff:ffff:ffff:ffff:ffff
33aaa:200::/243aaa:2ff:ffff:ffff:ffff:ffff:ffff:ffff
43aaa:300::/243aaa:3ff:ffff:ffff:ffff:ffff:ffff:ffff
53aaa:400::/243aaa:4ff:ffff:ffff:ffff:ffff:ffff:ffff
63aaa:500::/243aaa:5ff:ffff:ffff:ffff:ffff:ffff:ffff
73aaa:600::/243aaa:6ff:ffff:ffff:ffff:ffff:ffff:ffff
83aaa:700::/243aaa:7ff:ffff:ffff:ffff:ffff:ffff:ffff
93aaa:800::/243aaa:8ff:ffff:ffff:ffff:ffff:ffff:ffff
103aaa:900::/243aaa:9ff:ffff:ffff:ffff:ffff:ffff:ffff
113aaa:a00::/243aaa:aff:ffff:ffff:ffff:ffff:ffff:ffff
123aaa:b00::/243aaa:bff:ffff:ffff:ffff:ffff:ffff:ffff
133aaa:c00::/243aaa:cff:ffff:ffff:ffff:ffff:ffff:ffff
143aaa:d00::/243aaa:dff:ffff:ffff:ffff:ffff:ffff:ffff
153aaa:e00::/243aaa:eff:ffff:ffff:ffff:ffff:ffff:ffff
163aaa:f00::/243aaa:fff:ffff:ffff:ffff:ffff:ffff:ffff
173aaa:1000::/243aaa:10ff:ffff:ffff:ffff:ffff:ffff:ffff
183aaa:1100::/243aaa:11ff:ffff:ffff:ffff:ffff:ffff:ffff
193aaa:1200::/243aaa:12ff:ffff:ffff:ffff:ffff:ffff:ffff
203aaa:1300::/243aaa:13ff:ffff:ffff:ffff:ffff:ffff:ffff
213aaa:1400::/243aaa:14ff:ffff:ffff:ffff:ffff:ffff:ffff
223aaa:1500::/243aaa:15ff:ffff:ffff:ffff:ffff:ffff:ffff
233aaa:1600::/243aaa:16ff:ffff:ffff:ffff:ffff:ffff:ffff
243aaa:1700::/243aaa:17ff:ffff:ffff:ffff:ffff:ffff:ffff
253aaa:1800::/243aaa:18ff:ffff:ffff:ffff:ffff:ffff:ffff
263aaa:1900::/243aaa:19ff:ffff:ffff:ffff:ffff:ffff:ffff
273aaa:1a00::/243aaa:1aff:ffff:ffff:ffff:ffff:ffff:ffff
283aaa:1b00::/243aaa:1bff:ffff:ffff:ffff:ffff:ffff:ffff
293aaa:1c00::/243aaa:1cff:ffff:ffff:ffff:ffff:ffff:ffff
303aaa:1d00::/243aaa:1dff:ffff:ffff:ffff:ffff:ffff:ffff
313aaa:1e00::/243aaa:1eff:ffff:ffff:ffff:ffff:ffff:ffff
323aaa:1f00::/243aaa:1fff:ffff:ffff:ffff:ffff:ffff:ffff
333aaa:2000::/243aaa:20ff:ffff:ffff:ffff:ffff:ffff:ffff
343aaa:2100::/243aaa:21ff:ffff:ffff:ffff:ffff:ffff:ffff
353aaa:2200::/243aaa:22ff:ffff:ffff:ffff:ffff:ffff:ffff
363aaa:2300::/243aaa:23ff:ffff:ffff:ffff:ffff:ffff:ffff
373aaa:2400::/243aaa:24ff:ffff:ffff:ffff:ffff:ffff:ffff
383aaa:2500::/243aaa:25ff:ffff:ffff:ffff:ffff:ffff:ffff
393aaa:2600::/243aaa:26ff:ffff:ffff:ffff:ffff:ffff:ffff
403aaa:2700::/243aaa:27ff:ffff:ffff:ffff:ffff:ffff:ffff
413aaa:2800::/243aaa:28ff:ffff:ffff:ffff:ffff:ffff:ffff
423aaa:2900::/243aaa:29ff:ffff:ffff:ffff:ffff:ffff:ffff
433aaa:2a00::/243aaa:2aff:ffff:ffff:ffff:ffff:ffff:ffff
443aaa:2b00::/243aaa:2bff:ffff:ffff:ffff:ffff:ffff:ffff
453aaa:2c00::/243aaa:2cff:ffff:ffff:ffff:ffff:ffff:ffff
463aaa:2d00::/243aaa:2dff:ffff:ffff:ffff:ffff:ffff:ffff
473aaa:2e00::/243aaa:2eff:ffff:ffff:ffff:ffff:ffff:ffff
483aaa:2f00::/243aaa:2fff:ffff:ffff:ffff:ffff:ffff:ffff
493aaa:3000::/243aaa:30ff:ffff:ffff:ffff:ffff:ffff:ffff
503aaa:3100::/243aaa:31ff:ffff:ffff:ffff:ffff:ffff:ffff
513aaa:3200::/243aaa:32ff:ffff:ffff:ffff:ffff:ffff:ffff
523aaa:3300::/243aaa:33ff:ffff:ffff:ffff:ffff:ffff:ffff
533aaa:3400::/243aaa:34ff:ffff:ffff:ffff:ffff:ffff:ffff
543aaa:3500::/243aaa:35ff:ffff:ffff:ffff:ffff:ffff:ffff
553aaa:3600::/243aaa:36ff:ffff:ffff:ffff:ffff:ffff:ffff
563aaa:3700::/243aaa:37ff:ffff:ffff:ffff:ffff:ffff:ffff
573aaa:3800::/243aaa:38ff:ffff:ffff:ffff:ffff:ffff:ffff
583aaa:3900::/243aaa:39ff:ffff:ffff:ffff:ffff:ffff:ffff
593aaa:3a00::/243aaa:3aff:ffff:ffff:ffff:ffff:ffff:ffff
603aaa:3b00::/243aaa:3bff:ffff:ffff:ffff:ffff:ffff:ffff
613aaa:3c00::/243aaa:3cff:ffff:ffff:ffff:ffff:ffff:ffff
623aaa:3d00::/243aaa:3dff:ffff:ffff:ffff:ffff:ffff:ffff
633aaa:3e00::/243aaa:3eff:ffff:ffff:ffff:ffff:ffff:ffff
643aaa:3f00::/243aaa:3fff:ffff:ffff:ffff:ffff:ffff:ffff
653aaa:4000::/243aaa:40ff:ffff:ffff:ffff:ffff:ffff:ffff
663aaa:4100::/243aaa:41ff:ffff:ffff:ffff:ffff:ffff:ffff
673aaa:4200::/243aaa:42ff:ffff:ffff:ffff:ffff:ffff:ffff
683aaa:4300::/243aaa:43ff:ffff:ffff:ffff:ffff:ffff:ffff
693aaa:4400::/243aaa:44ff:ffff:ffff:ffff:ffff:ffff:ffff
703aaa:4500::/243aaa:45ff:ffff:ffff:ffff:ffff:ffff:ffff
713aaa:4600::/243aaa:46ff:ffff:ffff:ffff:ffff:ffff:ffff
723aaa:4700::/243aaa:47ff:ffff:ffff:ffff:ffff:ffff:ffff
733aaa:4800::/243aaa:48ff:ffff:ffff:ffff:ffff:ffff:ffff
743aaa:4900::/243aaa:49ff:ffff:ffff:ffff:ffff:ffff:ffff
753aaa:4a00::/243aaa:4aff:ffff:ffff:ffff:ffff:ffff:ffff
763aaa:4b00::/243aaa:4bff:ffff:ffff:ffff:ffff:ffff:ffff
773aaa:4c00::/243aaa:4cff:ffff:ffff:ffff:ffff:ffff:ffff
783aaa:4d00::/243aaa:4dff:ffff:ffff:ffff:ffff:ffff:ffff
793aaa:4e00::/243aaa:4eff:ffff:ffff:ffff:ffff:ffff:ffff
803aaa:4f00::/243aaa:4fff:ffff:ffff:ffff:ffff:ffff:ffff
813aaa:5000::/243aaa:50ff:ffff:ffff:ffff:ffff:ffff:ffff
823aaa:5100::/243aaa:51ff:ffff:ffff:ffff:ffff:ffff:ffff
833aaa:5200::/243aaa:52ff:ffff:ffff:ffff:ffff:ffff:ffff
843aaa:5300::/243aaa:53ff:ffff:ffff:ffff:ffff:ffff:ffff
853aaa:5400::/243aaa:54ff:ffff:ffff:ffff:ffff:ffff:ffff
863aaa:5500::/243aaa:55ff:ffff:ffff:ffff:ffff:ffff:ffff
873aaa:5600::/243aaa:56ff:ffff:ffff:ffff:ffff:ffff:ffff
883aaa:5700::/243aaa:57ff:ffff:ffff:ffff:ffff:ffff:ffff
893aaa:5800::/243aaa:58ff:ffff:ffff:ffff:ffff:ffff:ffff
903aaa:5900::/243aaa:59ff:ffff:ffff:ffff:ffff:ffff:ffff
913aaa:5a00::/243aaa:5aff:ffff:ffff:ffff:ffff:ffff:ffff
923aaa:5b00::/243aaa:5bff:ffff:ffff:ffff:ffff:ffff:ffff
933aaa:5c00::/243aaa:5cff:ffff:ffff:ffff:ffff:ffff:ffff
943aaa:5d00::/243aaa:5dff:ffff:ffff:ffff:ffff:ffff:ffff
953aaa:5e00::/243aaa:5eff:ffff:ffff:ffff:ffff:ffff:ffff
963aaa:5f00::/243aaa:5fff:ffff:ffff:ffff:ffff:ffff:ffff
973aaa:6000::/243aaa:60ff:ffff:ffff:ffff:ffff:ffff:ffff
983aaa:6100::/243aaa:61ff:ffff:ffff:ffff:ffff:ffff:ffff
993aaa:6200::/243aaa:62ff:ffff:ffff:ffff:ffff:ffff:ffff
1003aaa:6300::/243aaa:63ff:ffff:ffff:ffff:ffff:ffff:ffff
1013aaa:6400::/243aaa:64ff:ffff:ffff:ffff:ffff:ffff:ffff
1023aaa:6500::/243aaa:65ff:ffff:ffff:ffff:ffff:ffff:ffff
1033aaa:6600::/243aaa:66ff:ffff:ffff:ffff:ffff:ffff:ffff
1043aaa:6700::/243aaa:67ff:ffff:ffff:ffff:ffff:ffff:ffff
1053aaa:6800::/243aaa:68ff:ffff:ffff:ffff:ffff:ffff:ffff
1063aaa:6900::/243aaa:69ff:ffff:ffff:ffff:ffff:ffff:ffff
1073aaa:6a00::/243aaa:6aff:ffff:ffff:ffff:ffff:ffff:ffff
1083aaa:6b00::/243aaa:6bff:ffff:ffff:ffff:ffff:ffff:ffff
1093aaa:6c00::/243aaa:6cff:ffff:ffff:ffff:ffff:ffff:ffff
1103aaa:6d00::/243aaa:6dff:ffff:ffff:ffff:ffff:ffff:ffff
1113aaa:6e00::/243aaa:6eff:ffff:ffff:ffff:ffff:ffff:ffff
1123aaa:6f00::/243aaa:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1133aaa:7000::/243aaa:70ff:ffff:ffff:ffff:ffff:ffff:ffff
1143aaa:7100::/243aaa:71ff:ffff:ffff:ffff:ffff:ffff:ffff
1153aaa:7200::/243aaa:72ff:ffff:ffff:ffff:ffff:ffff:ffff
1163aaa:7300::/243aaa:73ff:ffff:ffff:ffff:ffff:ffff:ffff
1173aaa:7400::/243aaa:74ff:ffff:ffff:ffff:ffff:ffff:ffff
1183aaa:7500::/243aaa:75ff:ffff:ffff:ffff:ffff:ffff:ffff
1193aaa:7600::/243aaa:76ff:ffff:ffff:ffff:ffff:ffff:ffff
1203aaa:7700::/243aaa:77ff:ffff:ffff:ffff:ffff:ffff:ffff
1213aaa:7800::/243aaa:78ff:ffff:ffff:ffff:ffff:ffff:ffff
1223aaa:7900::/243aaa:79ff:ffff:ffff:ffff:ffff:ffff:ffff
1233aaa:7a00::/243aaa:7aff:ffff:ffff:ffff:ffff:ffff:ffff
1243aaa:7b00::/243aaa:7bff:ffff:ffff:ffff:ffff:ffff:ffff
1253aaa:7c00::/243aaa:7cff:ffff:ffff:ffff:ffff:ffff:ffff
1263aaa:7d00::/243aaa:7dff:ffff:ffff:ffff:ffff:ffff:ffff
1273aaa:7e00::/243aaa:7eff:ffff:ffff:ffff:ffff:ffff:ffff
1283aaa:7f00::/243aaa:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1293aaa:8000::/243aaa:80ff:ffff:ffff:ffff:ffff:ffff:ffff
1303aaa:8100::/243aaa:81ff:ffff:ffff:ffff:ffff:ffff:ffff
1313aaa:8200::/243aaa:82ff:ffff:ffff:ffff:ffff:ffff:ffff
1323aaa:8300::/243aaa:83ff:ffff:ffff:ffff:ffff:ffff:ffff
1333aaa:8400::/243aaa:84ff:ffff:ffff:ffff:ffff:ffff:ffff
1343aaa:8500::/243aaa:85ff:ffff:ffff:ffff:ffff:ffff:ffff
1353aaa:8600::/243aaa:86ff:ffff:ffff:ffff:ffff:ffff:ffff
1363aaa:8700::/243aaa:87ff:ffff:ffff:ffff:ffff:ffff:ffff
1373aaa:8800::/243aaa:88ff:ffff:ffff:ffff:ffff:ffff:ffff
1383aaa:8900::/243aaa:89ff:ffff:ffff:ffff:ffff:ffff:ffff
1393aaa:8a00::/243aaa:8aff:ffff:ffff:ffff:ffff:ffff:ffff
1403aaa:8b00::/243aaa:8bff:ffff:ffff:ffff:ffff:ffff:ffff
1413aaa:8c00::/243aaa:8cff:ffff:ffff:ffff:ffff:ffff:ffff
1423aaa:8d00::/243aaa:8dff:ffff:ffff:ffff:ffff:ffff:ffff
1433aaa:8e00::/243aaa:8eff:ffff:ffff:ffff:ffff:ffff:ffff
1443aaa:8f00::/243aaa:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1453aaa:9000::/243aaa:90ff:ffff:ffff:ffff:ffff:ffff:ffff
1463aaa:9100::/243aaa:91ff:ffff:ffff:ffff:ffff:ffff:ffff
1473aaa:9200::/243aaa:92ff:ffff:ffff:ffff:ffff:ffff:ffff
1483aaa:9300::/243aaa:93ff:ffff:ffff:ffff:ffff:ffff:ffff
1493aaa:9400::/243aaa:94ff:ffff:ffff:ffff:ffff:ffff:ffff
1503aaa:9500::/243aaa:95ff:ffff:ffff:ffff:ffff:ffff:ffff
1513aaa:9600::/243aaa:96ff:ffff:ffff:ffff:ffff:ffff:ffff
1523aaa:9700::/243aaa:97ff:ffff:ffff:ffff:ffff:ffff:ffff
1533aaa:9800::/243aaa:98ff:ffff:ffff:ffff:ffff:ffff:ffff
1543aaa:9900::/243aaa:99ff:ffff:ffff:ffff:ffff:ffff:ffff
1553aaa:9a00::/243aaa:9aff:ffff:ffff:ffff:ffff:ffff:ffff
1563aaa:9b00::/243aaa:9bff:ffff:ffff:ffff:ffff:ffff:ffff
1573aaa:9c00::/243aaa:9cff:ffff:ffff:ffff:ffff:ffff:ffff
1583aaa:9d00::/243aaa:9dff:ffff:ffff:ffff:ffff:ffff:ffff
1593aaa:9e00::/243aaa:9eff:ffff:ffff:ffff:ffff:ffff:ffff
1603aaa:9f00::/243aaa:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1613aaa:a000::/243aaa:a0ff:ffff:ffff:ffff:ffff:ffff:ffff
1623aaa:a100::/243aaa:a1ff:ffff:ffff:ffff:ffff:ffff:ffff
1633aaa:a200::/243aaa:a2ff:ffff:ffff:ffff:ffff:ffff:ffff
1643aaa:a300::/243aaa:a3ff:ffff:ffff:ffff:ffff:ffff:ffff
1653aaa:a400::/243aaa:a4ff:ffff:ffff:ffff:ffff:ffff:ffff
1663aaa:a500::/243aaa:a5ff:ffff:ffff:ffff:ffff:ffff:ffff
1673aaa:a600::/243aaa:a6ff:ffff:ffff:ffff:ffff:ffff:ffff
1683aaa:a700::/243aaa:a7ff:ffff:ffff:ffff:ffff:ffff:ffff
1693aaa:a800::/243aaa:a8ff:ffff:ffff:ffff:ffff:ffff:ffff
1703aaa:a900::/243aaa:a9ff:ffff:ffff:ffff:ffff:ffff:ffff
1713aaa:aa00::/243aaa:aaff:ffff:ffff:ffff:ffff:ffff:ffff
1723aaa:ab00::/243aaa:abff:ffff:ffff:ffff:ffff:ffff:ffff
1733aaa:ac00::/243aaa:acff:ffff:ffff:ffff:ffff:ffff:ffff
1743aaa:ad00::/243aaa:adff:ffff:ffff:ffff:ffff:ffff:ffff
1753aaa:ae00::/243aaa:aeff:ffff:ffff:ffff:ffff:ffff:ffff
1763aaa:af00::/243aaa:afff:ffff:ffff:ffff:ffff:ffff:ffff
1773aaa:b000::/243aaa:b0ff:ffff:ffff:ffff:ffff:ffff:ffff
1783aaa:b100::/243aaa:b1ff:ffff:ffff:ffff:ffff:ffff:ffff
1793aaa:b200::/243aaa:b2ff:ffff:ffff:ffff:ffff:ffff:ffff
1803aaa:b300::/243aaa:b3ff:ffff:ffff:ffff:ffff:ffff:ffff
1813aaa:b400::/243aaa:b4ff:ffff:ffff:ffff:ffff:ffff:ffff
1823aaa:b500::/243aaa:b5ff:ffff:ffff:ffff:ffff:ffff:ffff
1833aaa:b600::/243aaa:b6ff:ffff:ffff:ffff:ffff:ffff:ffff
1843aaa:b700::/243aaa:b7ff:ffff:ffff:ffff:ffff:ffff:ffff
1853aaa:b800::/243aaa:b8ff:ffff:ffff:ffff:ffff:ffff:ffff
1863aaa:b900::/243aaa:b9ff:ffff:ffff:ffff:ffff:ffff:ffff
1873aaa:ba00::/243aaa:baff:ffff:ffff:ffff:ffff:ffff:ffff
1883aaa:bb00::/243aaa:bbff:ffff:ffff:ffff:ffff:ffff:ffff
1893aaa:bc00::/243aaa:bcff:ffff:ffff:ffff:ffff:ffff:ffff
1903aaa:bd00::/243aaa:bdff:ffff:ffff:ffff:ffff:ffff:ffff
1913aaa:be00::/243aaa:beff:ffff:ffff:ffff:ffff:ffff:ffff
1923aaa:bf00::/243aaa:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1933aaa:c000::/243aaa:c0ff:ffff:ffff:ffff:ffff:ffff:ffff
1943aaa:c100::/243aaa:c1ff:ffff:ffff:ffff:ffff:ffff:ffff
1953aaa:c200::/243aaa:c2ff:ffff:ffff:ffff:ffff:ffff:ffff
1963aaa:c300::/243aaa:c3ff:ffff:ffff:ffff:ffff:ffff:ffff
1973aaa:c400::/243aaa:c4ff:ffff:ffff:ffff:ffff:ffff:ffff
1983aaa:c500::/243aaa:c5ff:ffff:ffff:ffff:ffff:ffff:ffff
1993aaa:c600::/243aaa:c6ff:ffff:ffff:ffff:ffff:ffff:ffff
2003aaa:c700::/243aaa:c7ff:ffff:ffff:ffff:ffff:ffff:ffff
2013aaa:c800::/243aaa:c8ff:ffff:ffff:ffff:ffff:ffff:ffff
2023aaa:c900::/243aaa:c9ff:ffff:ffff:ffff:ffff:ffff:ffff
2033aaa:ca00::/243aaa:caff:ffff:ffff:ffff:ffff:ffff:ffff
2043aaa:cb00::/243aaa:cbff:ffff:ffff:ffff:ffff:ffff:ffff
2053aaa:cc00::/243aaa:ccff:ffff:ffff:ffff:ffff:ffff:ffff
2063aaa:cd00::/243aaa:cdff:ffff:ffff:ffff:ffff:ffff:ffff
2073aaa:ce00::/243aaa:ceff:ffff:ffff:ffff:ffff:ffff:ffff
2083aaa:cf00::/243aaa:cfff:ffff:ffff:ffff:ffff:ffff:ffff
2093aaa:d000::/243aaa:d0ff:ffff:ffff:ffff:ffff:ffff:ffff
2103aaa:d100::/243aaa:d1ff:ffff:ffff:ffff:ffff:ffff:ffff
2113aaa:d200::/243aaa:d2ff:ffff:ffff:ffff:ffff:ffff:ffff
2123aaa:d300::/243aaa:d3ff:ffff:ffff:ffff:ffff:ffff:ffff
2133aaa:d400::/243aaa:d4ff:ffff:ffff:ffff:ffff:ffff:ffff
2143aaa:d500::/243aaa:d5ff:ffff:ffff:ffff:ffff:ffff:ffff
2153aaa:d600::/243aaa:d6ff:ffff:ffff:ffff:ffff:ffff:ffff
2163aaa:d700::/243aaa:d7ff:ffff:ffff:ffff:ffff:ffff:ffff
2173aaa:d800::/243aaa:d8ff:ffff:ffff:ffff:ffff:ffff:ffff
2183aaa:d900::/243aaa:d9ff:ffff:ffff:ffff:ffff:ffff:ffff
2193aaa:da00::/243aaa:daff:ffff:ffff:ffff:ffff:ffff:ffff
2203aaa:db00::/243aaa:dbff:ffff:ffff:ffff:ffff:ffff:ffff
2213aaa:dc00::/243aaa:dcff:ffff:ffff:ffff:ffff:ffff:ffff
2223aaa:dd00::/243aaa:ddff:ffff:ffff:ffff:ffff:ffff:ffff
2233aaa:de00::/243aaa:deff:ffff:ffff:ffff:ffff:ffff:ffff
2243aaa:df00::/243aaa:dfff:ffff:ffff:ffff:ffff:ffff:ffff
2253aaa:e000::/243aaa:e0ff:ffff:ffff:ffff:ffff:ffff:ffff
2263aaa:e100::/243aaa:e1ff:ffff:ffff:ffff:ffff:ffff:ffff
2273aaa:e200::/243aaa:e2ff:ffff:ffff:ffff:ffff:ffff:ffff
2283aaa:e300::/243aaa:e3ff:ffff:ffff:ffff:ffff:ffff:ffff
2293aaa:e400::/243aaa:e4ff:ffff:ffff:ffff:ffff:ffff:ffff
2303aaa:e500::/243aaa:e5ff:ffff:ffff:ffff:ffff:ffff:ffff
2313aaa:e600::/243aaa:e6ff:ffff:ffff:ffff:ffff:ffff:ffff
2323aaa:e700::/243aaa:e7ff:ffff:ffff:ffff:ffff:ffff:ffff
2333aaa:e800::/243aaa:e8ff:ffff:ffff:ffff:ffff:ffff:ffff
2343aaa:e900::/243aaa:e9ff:ffff:ffff:ffff:ffff:ffff:ffff
2353aaa:ea00::/243aaa:eaff:ffff:ffff:ffff:ffff:ffff:ffff
2363aaa:eb00::/243aaa:ebff:ffff:ffff:ffff:ffff:ffff:ffff
2373aaa:ec00::/243aaa:ecff:ffff:ffff:ffff:ffff:ffff:ffff
2383aaa:ed00::/243aaa:edff:ffff:ffff:ffff:ffff:ffff:ffff
2393aaa:ee00::/243aaa:eeff:ffff:ffff:ffff:ffff:ffff:ffff
2403aaa:ef00::/243aaa:efff:ffff:ffff:ffff:ffff:ffff:ffff
2413aaa:f000::/243aaa:f0ff:ffff:ffff:ffff:ffff:ffff:ffff
2423aaa:f100::/243aaa:f1ff:ffff:ffff:ffff:ffff:ffff:ffff
2433aaa:f200::/243aaa:f2ff:ffff:ffff:ffff:ffff:ffff:ffff
2443aaa:f300::/243aaa:f3ff:ffff:ffff:ffff:ffff:ffff:ffff
2453aaa:f400::/243aaa:f4ff:ffff:ffff:ffff:ffff:ffff:ffff
2463aaa:f500::/243aaa:f5ff:ffff:ffff:ffff:ffff:ffff:ffff
2473aaa:f600::/243aaa:f6ff:ffff:ffff:ffff:ffff:ffff:ffff
2483aaa:f700::/243aaa:f7ff:ffff:ffff:ffff:ffff:ffff:ffff
2493aaa:f800::/243aaa:f8ff:ffff:ffff:ffff:ffff:ffff:ffff
2503aaa:f900::/243aaa:f9ff:ffff:ffff:ffff:ffff:ffff:ffff
2513aaa:fa00::/243aaa:faff:ffff:ffff:ffff:ffff:ffff:ffff
2523aaa:fb00::/243aaa:fbff:ffff:ffff:ffff:ffff:ffff:ffff
2533aaa:fc00::/243aaa:fcff:ffff:ffff:ffff:ffff:ffff:ffff
2543aaa:fd00::/243aaa:fdff:ffff:ffff:ffff:ffff:ffff:ffff
2553aaa:fe00::/243aaa:feff:ffff:ffff:ffff:ffff:ffff:ffff
2563aaa:ff00::/243aaa:ffff: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.