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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.

Network4.0.0.0/11
Usable hosts2,097,150
Subnet mask255.224.0.0
Addresses2,097,152
Network address
4.0.0.0
Broadcast address
4.31.255.255
First usable
4.0.0.1
Last usable
4.31.255.254
Usable hosts
2,097,150 (2,097,152 less the network and broadcast addresses)
Subnet mask
255.224.0.0
Wildcard mask
0.31.255.255 (Cisco ACLs, OSPF)
Prefix length
/11
Type
Public public
Old class
A (default /8)
As numbers
Hex 04000000 · Integer 67108864 to 69206015
Reverse DNS zones
0.4.in-addr.arpa
1.4.in-addr.arpa
2.4.in-addr.arpa
3.4.in-addr.arpa
4.4.in-addr.arpa
5.4.in-addr.arpa
6.4.in-addr.arpa
7.4.in-addr.arpa
8.4.in-addr.arpa
9.4.in-addr.arpa
10.4.in-addr.arpa
11.4.in-addr.arpa
12.4.in-addr.arpa
13.4.in-addr.arpa
14.4.in-addr.arpa
15.4.in-addr.arpa
and 16 more
/11 is not on a 8-bit boundary, so it takes 32 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00000100.00000000.00000000.000000004.0.0.0
Subnet mask11111111.11100000.00000000.00000000255.224.0.0
Network00000100.00000000.00000000.000000004.0.0.0
Broadcast00000100.00011111.11111111.111111114.31.255.255
Split into smaller subnets/19
/12 (2)/13 (4)/14 (8)/15 (16)/16 (32)/17 (64)/18 (128)/19 (256)/20 (512)/21 (1,024)/22 (2,048)/23 (4,096)

4.0.0.0/11 makes 256 subnets of /19.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
14.0.0.0/194.0.0.1 to 4.0.31.2544.0.31.2558,190
24.0.32.0/194.0.32.1 to 4.0.63.2544.0.63.2558,190
34.0.64.0/194.0.64.1 to 4.0.95.2544.0.95.2558,190
44.0.96.0/194.0.96.1 to 4.0.127.2544.0.127.2558,190
54.0.128.0/194.0.128.1 to 4.0.159.2544.0.159.2558,190
64.0.160.0/194.0.160.1 to 4.0.191.2544.0.191.2558,190
74.0.192.0/194.0.192.1 to 4.0.223.2544.0.223.2558,190
84.0.224.0/194.0.224.1 to 4.0.255.2544.0.255.2558,190
94.1.0.0/194.1.0.1 to 4.1.31.2544.1.31.2558,190
104.1.32.0/194.1.32.1 to 4.1.63.2544.1.63.2558,190
114.1.64.0/194.1.64.1 to 4.1.95.2544.1.95.2558,190
124.1.96.0/194.1.96.1 to 4.1.127.2544.1.127.2558,190
134.1.128.0/194.1.128.1 to 4.1.159.2544.1.159.2558,190
144.1.160.0/194.1.160.1 to 4.1.191.2544.1.191.2558,190
154.1.192.0/194.1.192.1 to 4.1.223.2544.1.223.2558,190
164.1.224.0/194.1.224.1 to 4.1.255.2544.1.255.2558,190
174.2.0.0/194.2.0.1 to 4.2.31.2544.2.31.2558,190
184.2.32.0/194.2.32.1 to 4.2.63.2544.2.63.2558,190
194.2.64.0/194.2.64.1 to 4.2.95.2544.2.95.2558,190
204.2.96.0/194.2.96.1 to 4.2.127.2544.2.127.2558,190
214.2.128.0/194.2.128.1 to 4.2.159.2544.2.159.2558,190
224.2.160.0/194.2.160.1 to 4.2.191.2544.2.191.2558,190
234.2.192.0/194.2.192.1 to 4.2.223.2544.2.223.2558,190
244.2.224.0/194.2.224.1 to 4.2.255.2544.2.255.2558,190
254.3.0.0/194.3.0.1 to 4.3.31.2544.3.31.2558,190
264.3.32.0/194.3.32.1 to 4.3.63.2544.3.63.2558,190
274.3.64.0/194.3.64.1 to 4.3.95.2544.3.95.2558,190
284.3.96.0/194.3.96.1 to 4.3.127.2544.3.127.2558,190
294.3.128.0/194.3.128.1 to 4.3.159.2544.3.159.2558,190
304.3.160.0/194.3.160.1 to 4.3.191.2544.3.191.2558,190
314.3.192.0/194.3.192.1 to 4.3.223.2544.3.223.2558,190
324.3.224.0/194.3.224.1 to 4.3.255.2544.3.255.2558,190
334.4.0.0/194.4.0.1 to 4.4.31.2544.4.31.2558,190
344.4.32.0/194.4.32.1 to 4.4.63.2544.4.63.2558,190
354.4.64.0/194.4.64.1 to 4.4.95.2544.4.95.2558,190
364.4.96.0/194.4.96.1 to 4.4.127.2544.4.127.2558,190
374.4.128.0/194.4.128.1 to 4.4.159.2544.4.159.2558,190
384.4.160.0/194.4.160.1 to 4.4.191.2544.4.191.2558,190
394.4.192.0/194.4.192.1 to 4.4.223.2544.4.223.2558,190
404.4.224.0/194.4.224.1 to 4.4.255.2544.4.255.2558,190
414.5.0.0/194.5.0.1 to 4.5.31.2544.5.31.2558,190
424.5.32.0/194.5.32.1 to 4.5.63.2544.5.63.2558,190
434.5.64.0/194.5.64.1 to 4.5.95.2544.5.95.2558,190
444.5.96.0/194.5.96.1 to 4.5.127.2544.5.127.2558,190
454.5.128.0/194.5.128.1 to 4.5.159.2544.5.159.2558,190
464.5.160.0/194.5.160.1 to 4.5.191.2544.5.191.2558,190
474.5.192.0/194.5.192.1 to 4.5.223.2544.5.223.2558,190
484.5.224.0/194.5.224.1 to 4.5.255.2544.5.255.2558,190
494.6.0.0/194.6.0.1 to 4.6.31.2544.6.31.2558,190
504.6.32.0/194.6.32.1 to 4.6.63.2544.6.63.2558,190
514.6.64.0/194.6.64.1 to 4.6.95.2544.6.95.2558,190
524.6.96.0/194.6.96.1 to 4.6.127.2544.6.127.2558,190
534.6.128.0/194.6.128.1 to 4.6.159.2544.6.159.2558,190
544.6.160.0/194.6.160.1 to 4.6.191.2544.6.191.2558,190
554.6.192.0/194.6.192.1 to 4.6.223.2544.6.223.2558,190
564.6.224.0/194.6.224.1 to 4.6.255.2544.6.255.2558,190
574.7.0.0/194.7.0.1 to 4.7.31.2544.7.31.2558,190
584.7.32.0/194.7.32.1 to 4.7.63.2544.7.63.2558,190
594.7.64.0/194.7.64.1 to 4.7.95.2544.7.95.2558,190
604.7.96.0/194.7.96.1 to 4.7.127.2544.7.127.2558,190
614.7.128.0/194.7.128.1 to 4.7.159.2544.7.159.2558,190
624.7.160.0/194.7.160.1 to 4.7.191.2544.7.191.2558,190
634.7.192.0/194.7.192.1 to 4.7.223.2544.7.223.2558,190
644.7.224.0/194.7.224.1 to 4.7.255.2544.7.255.2558,190
654.8.0.0/194.8.0.1 to 4.8.31.2544.8.31.2558,190
664.8.32.0/194.8.32.1 to 4.8.63.2544.8.63.2558,190
674.8.64.0/194.8.64.1 to 4.8.95.2544.8.95.2558,190
684.8.96.0/194.8.96.1 to 4.8.127.2544.8.127.2558,190
694.8.128.0/194.8.128.1 to 4.8.159.2544.8.159.2558,190
704.8.160.0/194.8.160.1 to 4.8.191.2544.8.191.2558,190
714.8.192.0/194.8.192.1 to 4.8.223.2544.8.223.2558,190
724.8.224.0/194.8.224.1 to 4.8.255.2544.8.255.2558,190
734.9.0.0/194.9.0.1 to 4.9.31.2544.9.31.2558,190
744.9.32.0/194.9.32.1 to 4.9.63.2544.9.63.2558,190
754.9.64.0/194.9.64.1 to 4.9.95.2544.9.95.2558,190
764.9.96.0/194.9.96.1 to 4.9.127.2544.9.127.2558,190
774.9.128.0/194.9.128.1 to 4.9.159.2544.9.159.2558,190
784.9.160.0/194.9.160.1 to 4.9.191.2544.9.191.2558,190
794.9.192.0/194.9.192.1 to 4.9.223.2544.9.223.2558,190
804.9.224.0/194.9.224.1 to 4.9.255.2544.9.255.2558,190
814.10.0.0/194.10.0.1 to 4.10.31.2544.10.31.2558,190
824.10.32.0/194.10.32.1 to 4.10.63.2544.10.63.2558,190
834.10.64.0/194.10.64.1 to 4.10.95.2544.10.95.2558,190
844.10.96.0/194.10.96.1 to 4.10.127.2544.10.127.2558,190
854.10.128.0/194.10.128.1 to 4.10.159.2544.10.159.2558,190
864.10.160.0/194.10.160.1 to 4.10.191.2544.10.191.2558,190
874.10.192.0/194.10.192.1 to 4.10.223.2544.10.223.2558,190
884.10.224.0/194.10.224.1 to 4.10.255.2544.10.255.2558,190
894.11.0.0/194.11.0.1 to 4.11.31.2544.11.31.2558,190
904.11.32.0/194.11.32.1 to 4.11.63.2544.11.63.2558,190
914.11.64.0/194.11.64.1 to 4.11.95.2544.11.95.2558,190
924.11.96.0/194.11.96.1 to 4.11.127.2544.11.127.2558,190
934.11.128.0/194.11.128.1 to 4.11.159.2544.11.159.2558,190
944.11.160.0/194.11.160.1 to 4.11.191.2544.11.191.2558,190
954.11.192.0/194.11.192.1 to 4.11.223.2544.11.223.2558,190
964.11.224.0/194.11.224.1 to 4.11.255.2544.11.255.2558,190
974.12.0.0/194.12.0.1 to 4.12.31.2544.12.31.2558,190
984.12.32.0/194.12.32.1 to 4.12.63.2544.12.63.2558,190
994.12.64.0/194.12.64.1 to 4.12.95.2544.12.95.2558,190
1004.12.96.0/194.12.96.1 to 4.12.127.2544.12.127.2558,190
1014.12.128.0/194.12.128.1 to 4.12.159.2544.12.159.2558,190
1024.12.160.0/194.12.160.1 to 4.12.191.2544.12.191.2558,190
1034.12.192.0/194.12.192.1 to 4.12.223.2544.12.223.2558,190
1044.12.224.0/194.12.224.1 to 4.12.255.2544.12.255.2558,190
1054.13.0.0/194.13.0.1 to 4.13.31.2544.13.31.2558,190
1064.13.32.0/194.13.32.1 to 4.13.63.2544.13.63.2558,190
1074.13.64.0/194.13.64.1 to 4.13.95.2544.13.95.2558,190
1084.13.96.0/194.13.96.1 to 4.13.127.2544.13.127.2558,190
1094.13.128.0/194.13.128.1 to 4.13.159.2544.13.159.2558,190
1104.13.160.0/194.13.160.1 to 4.13.191.2544.13.191.2558,190
1114.13.192.0/194.13.192.1 to 4.13.223.2544.13.223.2558,190
1124.13.224.0/194.13.224.1 to 4.13.255.2544.13.255.2558,190
1134.14.0.0/194.14.0.1 to 4.14.31.2544.14.31.2558,190
1144.14.32.0/194.14.32.1 to 4.14.63.2544.14.63.2558,190
1154.14.64.0/194.14.64.1 to 4.14.95.2544.14.95.2558,190
1164.14.96.0/194.14.96.1 to 4.14.127.2544.14.127.2558,190
1174.14.128.0/194.14.128.1 to 4.14.159.2544.14.159.2558,190
1184.14.160.0/194.14.160.1 to 4.14.191.2544.14.191.2558,190
1194.14.192.0/194.14.192.1 to 4.14.223.2544.14.223.2558,190
1204.14.224.0/194.14.224.1 to 4.14.255.2544.14.255.2558,190
1214.15.0.0/194.15.0.1 to 4.15.31.2544.15.31.2558,190
1224.15.32.0/194.15.32.1 to 4.15.63.2544.15.63.2558,190
1234.15.64.0/194.15.64.1 to 4.15.95.2544.15.95.2558,190
1244.15.96.0/194.15.96.1 to 4.15.127.2544.15.127.2558,190
1254.15.128.0/194.15.128.1 to 4.15.159.2544.15.159.2558,190
1264.15.160.0/194.15.160.1 to 4.15.191.2544.15.191.2558,190
1274.15.192.0/194.15.192.1 to 4.15.223.2544.15.223.2558,190
1284.15.224.0/194.15.224.1 to 4.15.255.2544.15.255.2558,190
1294.16.0.0/194.16.0.1 to 4.16.31.2544.16.31.2558,190
1304.16.32.0/194.16.32.1 to 4.16.63.2544.16.63.2558,190
1314.16.64.0/194.16.64.1 to 4.16.95.2544.16.95.2558,190
1324.16.96.0/194.16.96.1 to 4.16.127.2544.16.127.2558,190
1334.16.128.0/194.16.128.1 to 4.16.159.2544.16.159.2558,190
1344.16.160.0/194.16.160.1 to 4.16.191.2544.16.191.2558,190
1354.16.192.0/194.16.192.1 to 4.16.223.2544.16.223.2558,190
1364.16.224.0/194.16.224.1 to 4.16.255.2544.16.255.2558,190
1374.17.0.0/194.17.0.1 to 4.17.31.2544.17.31.2558,190
1384.17.32.0/194.17.32.1 to 4.17.63.2544.17.63.2558,190
1394.17.64.0/194.17.64.1 to 4.17.95.2544.17.95.2558,190
1404.17.96.0/194.17.96.1 to 4.17.127.2544.17.127.2558,190
1414.17.128.0/194.17.128.1 to 4.17.159.2544.17.159.2558,190
1424.17.160.0/194.17.160.1 to 4.17.191.2544.17.191.2558,190
1434.17.192.0/194.17.192.1 to 4.17.223.2544.17.223.2558,190
1444.17.224.0/194.17.224.1 to 4.17.255.2544.17.255.2558,190
1454.18.0.0/194.18.0.1 to 4.18.31.2544.18.31.2558,190
1464.18.32.0/194.18.32.1 to 4.18.63.2544.18.63.2558,190
1474.18.64.0/194.18.64.1 to 4.18.95.2544.18.95.2558,190
1484.18.96.0/194.18.96.1 to 4.18.127.2544.18.127.2558,190
1494.18.128.0/194.18.128.1 to 4.18.159.2544.18.159.2558,190
1504.18.160.0/194.18.160.1 to 4.18.191.2544.18.191.2558,190
1514.18.192.0/194.18.192.1 to 4.18.223.2544.18.223.2558,190
1524.18.224.0/194.18.224.1 to 4.18.255.2544.18.255.2558,190
1534.19.0.0/194.19.0.1 to 4.19.31.2544.19.31.2558,190
1544.19.32.0/194.19.32.1 to 4.19.63.2544.19.63.2558,190
1554.19.64.0/194.19.64.1 to 4.19.95.2544.19.95.2558,190
1564.19.96.0/194.19.96.1 to 4.19.127.2544.19.127.2558,190
1574.19.128.0/194.19.128.1 to 4.19.159.2544.19.159.2558,190
1584.19.160.0/194.19.160.1 to 4.19.191.2544.19.191.2558,190
1594.19.192.0/194.19.192.1 to 4.19.223.2544.19.223.2558,190
1604.19.224.0/194.19.224.1 to 4.19.255.2544.19.255.2558,190
1614.20.0.0/194.20.0.1 to 4.20.31.2544.20.31.2558,190
1624.20.32.0/194.20.32.1 to 4.20.63.2544.20.63.2558,190
1634.20.64.0/194.20.64.1 to 4.20.95.2544.20.95.2558,190
1644.20.96.0/194.20.96.1 to 4.20.127.2544.20.127.2558,190
1654.20.128.0/194.20.128.1 to 4.20.159.2544.20.159.2558,190
1664.20.160.0/194.20.160.1 to 4.20.191.2544.20.191.2558,190
1674.20.192.0/194.20.192.1 to 4.20.223.2544.20.223.2558,190
1684.20.224.0/194.20.224.1 to 4.20.255.2544.20.255.2558,190
1694.21.0.0/194.21.0.1 to 4.21.31.2544.21.31.2558,190
1704.21.32.0/194.21.32.1 to 4.21.63.2544.21.63.2558,190
1714.21.64.0/194.21.64.1 to 4.21.95.2544.21.95.2558,190
1724.21.96.0/194.21.96.1 to 4.21.127.2544.21.127.2558,190
1734.21.128.0/194.21.128.1 to 4.21.159.2544.21.159.2558,190
1744.21.160.0/194.21.160.1 to 4.21.191.2544.21.191.2558,190
1754.21.192.0/194.21.192.1 to 4.21.223.2544.21.223.2558,190
1764.21.224.0/194.21.224.1 to 4.21.255.2544.21.255.2558,190
1774.22.0.0/194.22.0.1 to 4.22.31.2544.22.31.2558,190
1784.22.32.0/194.22.32.1 to 4.22.63.2544.22.63.2558,190
1794.22.64.0/194.22.64.1 to 4.22.95.2544.22.95.2558,190
1804.22.96.0/194.22.96.1 to 4.22.127.2544.22.127.2558,190
1814.22.128.0/194.22.128.1 to 4.22.159.2544.22.159.2558,190
1824.22.160.0/194.22.160.1 to 4.22.191.2544.22.191.2558,190
1834.22.192.0/194.22.192.1 to 4.22.223.2544.22.223.2558,190
1844.22.224.0/194.22.224.1 to 4.22.255.2544.22.255.2558,190
1854.23.0.0/194.23.0.1 to 4.23.31.2544.23.31.2558,190
1864.23.32.0/194.23.32.1 to 4.23.63.2544.23.63.2558,190
1874.23.64.0/194.23.64.1 to 4.23.95.2544.23.95.2558,190
1884.23.96.0/194.23.96.1 to 4.23.127.2544.23.127.2558,190
1894.23.128.0/194.23.128.1 to 4.23.159.2544.23.159.2558,190
1904.23.160.0/194.23.160.1 to 4.23.191.2544.23.191.2558,190
1914.23.192.0/194.23.192.1 to 4.23.223.2544.23.223.2558,190
1924.23.224.0/194.23.224.1 to 4.23.255.2544.23.255.2558,190
1934.24.0.0/194.24.0.1 to 4.24.31.2544.24.31.2558,190
1944.24.32.0/194.24.32.1 to 4.24.63.2544.24.63.2558,190
1954.24.64.0/194.24.64.1 to 4.24.95.2544.24.95.2558,190
1964.24.96.0/194.24.96.1 to 4.24.127.2544.24.127.2558,190
1974.24.128.0/194.24.128.1 to 4.24.159.2544.24.159.2558,190
1984.24.160.0/194.24.160.1 to 4.24.191.2544.24.191.2558,190
1994.24.192.0/194.24.192.1 to 4.24.223.2544.24.223.2558,190
2004.24.224.0/194.24.224.1 to 4.24.255.2544.24.255.2558,190
2014.25.0.0/194.25.0.1 to 4.25.31.2544.25.31.2558,190
2024.25.32.0/194.25.32.1 to 4.25.63.2544.25.63.2558,190
2034.25.64.0/194.25.64.1 to 4.25.95.2544.25.95.2558,190
2044.25.96.0/194.25.96.1 to 4.25.127.2544.25.127.2558,190
2054.25.128.0/194.25.128.1 to 4.25.159.2544.25.159.2558,190
2064.25.160.0/194.25.160.1 to 4.25.191.2544.25.191.2558,190
2074.25.192.0/194.25.192.1 to 4.25.223.2544.25.223.2558,190
2084.25.224.0/194.25.224.1 to 4.25.255.2544.25.255.2558,190
2094.26.0.0/194.26.0.1 to 4.26.31.2544.26.31.2558,190
2104.26.32.0/194.26.32.1 to 4.26.63.2544.26.63.2558,190
2114.26.64.0/194.26.64.1 to 4.26.95.2544.26.95.2558,190
2124.26.96.0/194.26.96.1 to 4.26.127.2544.26.127.2558,190
2134.26.128.0/194.26.128.1 to 4.26.159.2544.26.159.2558,190
2144.26.160.0/194.26.160.1 to 4.26.191.2544.26.191.2558,190
2154.26.192.0/194.26.192.1 to 4.26.223.2544.26.223.2558,190
2164.26.224.0/194.26.224.1 to 4.26.255.2544.26.255.2558,190
2174.27.0.0/194.27.0.1 to 4.27.31.2544.27.31.2558,190
2184.27.32.0/194.27.32.1 to 4.27.63.2544.27.63.2558,190
2194.27.64.0/194.27.64.1 to 4.27.95.2544.27.95.2558,190
2204.27.96.0/194.27.96.1 to 4.27.127.2544.27.127.2558,190
2214.27.128.0/194.27.128.1 to 4.27.159.2544.27.159.2558,190
2224.27.160.0/194.27.160.1 to 4.27.191.2544.27.191.2558,190
2234.27.192.0/194.27.192.1 to 4.27.223.2544.27.223.2558,190
2244.27.224.0/194.27.224.1 to 4.27.255.2544.27.255.2558,190
2254.28.0.0/194.28.0.1 to 4.28.31.2544.28.31.2558,190
2264.28.32.0/194.28.32.1 to 4.28.63.2544.28.63.2558,190
2274.28.64.0/194.28.64.1 to 4.28.95.2544.28.95.2558,190
2284.28.96.0/194.28.96.1 to 4.28.127.2544.28.127.2558,190
2294.28.128.0/194.28.128.1 to 4.28.159.2544.28.159.2558,190
2304.28.160.0/194.28.160.1 to 4.28.191.2544.28.191.2558,190
2314.28.192.0/194.28.192.1 to 4.28.223.2544.28.223.2558,190
2324.28.224.0/194.28.224.1 to 4.28.255.2544.28.255.2558,190
2334.29.0.0/194.29.0.1 to 4.29.31.2544.29.31.2558,190
2344.29.32.0/194.29.32.1 to 4.29.63.2544.29.63.2558,190
2354.29.64.0/194.29.64.1 to 4.29.95.2544.29.95.2558,190
2364.29.96.0/194.29.96.1 to 4.29.127.2544.29.127.2558,190
2374.29.128.0/194.29.128.1 to 4.29.159.2544.29.159.2558,190
2384.29.160.0/194.29.160.1 to 4.29.191.2544.29.191.2558,190
2394.29.192.0/194.29.192.1 to 4.29.223.2544.29.223.2558,190
2404.29.224.0/194.29.224.1 to 4.29.255.2544.29.255.2558,190
2414.30.0.0/194.30.0.1 to 4.30.31.2544.30.31.2558,190
2424.30.32.0/194.30.32.1 to 4.30.63.2544.30.63.2558,190
2434.30.64.0/194.30.64.1 to 4.30.95.2544.30.95.2558,190
2444.30.96.0/194.30.96.1 to 4.30.127.2544.30.127.2558,190
2454.30.128.0/194.30.128.1 to 4.30.159.2544.30.159.2558,190
2464.30.160.0/194.30.160.1 to 4.30.191.2544.30.191.2558,190
2474.30.192.0/194.30.192.1 to 4.30.223.2544.30.223.2558,190
2484.30.224.0/194.30.224.1 to 4.30.255.2544.30.255.2558,190
2494.31.0.0/194.31.0.1 to 4.31.31.2544.31.31.2558,190
2504.31.32.0/194.31.32.1 to 4.31.63.2544.31.63.2558,190
2514.31.64.0/194.31.64.1 to 4.31.95.2544.31.95.2558,190
2524.31.96.0/194.31.96.1 to 4.31.127.2544.31.127.2558,190
2534.31.128.0/194.31.128.1 to 4.31.159.2544.31.159.2558,190
2544.31.160.0/194.31.160.1 to 4.31.191.2544.31.191.2558,190
2554.31.192.0/194.31.192.1 to 4.31.223.2544.31.223.2558,190
2564.31.224.0/194.31.224.1 to 4.31.255.2544.31.255.2558,190

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.