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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.

Network1.192.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
1.192.0.0
Broadcast address
1.255.255.255
First usable
1.192.0.1
Last usable
1.255.255.254
Usable hosts
4,194,302 (4,194,304 less the network and broadcast addresses)
Subnet mask
255.192.0.0
Wildcard mask
0.63.255.255 (Cisco ACLs, OSPF)
Prefix length
/10
Type
Public public
Old class
A (default /8)
As numbers
Hex 01C00000 · Integer 29360128 to 33554431
Reverse DNS zones
192.1.in-addr.arpa
193.1.in-addr.arpa
194.1.in-addr.arpa
195.1.in-addr.arpa
196.1.in-addr.arpa
197.1.in-addr.arpa
198.1.in-addr.arpa
199.1.in-addr.arpa
200.1.in-addr.arpa
201.1.in-addr.arpa
202.1.in-addr.arpa
203.1.in-addr.arpa
204.1.in-addr.arpa
205.1.in-addr.arpa
206.1.in-addr.arpa
207.1.in-addr.arpa
and 48 more
/10 is not on a 8-bit boundary, so it takes 64 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00000001.11000000.00000000.000000001.192.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network00000001.11000000.00000000.000000001.192.0.0
Broadcast00000001.11111111.11111111.111111111.255.255.255
Split into smaller subnets/18
/11 (2)/12 (4)/13 (8)/14 (16)/15 (32)/16 (64)/17 (128)/18 (256)/19 (512)/20 (1,024)/21 (2,048)/22 (4,096)

1.192.0.0/10 makes 256 subnets of /18.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
11.192.0.0/181.192.0.1 to 1.192.63.2541.192.63.25516,382
21.192.64.0/181.192.64.1 to 1.192.127.2541.192.127.25516,382
31.192.128.0/181.192.128.1 to 1.192.191.2541.192.191.25516,382
41.192.192.0/181.192.192.1 to 1.192.255.2541.192.255.25516,382
51.193.0.0/181.193.0.1 to 1.193.63.2541.193.63.25516,382
61.193.64.0/181.193.64.1 to 1.193.127.2541.193.127.25516,382
71.193.128.0/181.193.128.1 to 1.193.191.2541.193.191.25516,382
81.193.192.0/181.193.192.1 to 1.193.255.2541.193.255.25516,382
91.194.0.0/181.194.0.1 to 1.194.63.2541.194.63.25516,382
101.194.64.0/181.194.64.1 to 1.194.127.2541.194.127.25516,382
111.194.128.0/181.194.128.1 to 1.194.191.2541.194.191.25516,382
121.194.192.0/181.194.192.1 to 1.194.255.2541.194.255.25516,382
131.195.0.0/181.195.0.1 to 1.195.63.2541.195.63.25516,382
141.195.64.0/181.195.64.1 to 1.195.127.2541.195.127.25516,382
151.195.128.0/181.195.128.1 to 1.195.191.2541.195.191.25516,382
161.195.192.0/181.195.192.1 to 1.195.255.2541.195.255.25516,382
171.196.0.0/181.196.0.1 to 1.196.63.2541.196.63.25516,382
181.196.64.0/181.196.64.1 to 1.196.127.2541.196.127.25516,382
191.196.128.0/181.196.128.1 to 1.196.191.2541.196.191.25516,382
201.196.192.0/181.196.192.1 to 1.196.255.2541.196.255.25516,382
211.197.0.0/181.197.0.1 to 1.197.63.2541.197.63.25516,382
221.197.64.0/181.197.64.1 to 1.197.127.2541.197.127.25516,382
231.197.128.0/181.197.128.1 to 1.197.191.2541.197.191.25516,382
241.197.192.0/181.197.192.1 to 1.197.255.2541.197.255.25516,382
251.198.0.0/181.198.0.1 to 1.198.63.2541.198.63.25516,382
261.198.64.0/181.198.64.1 to 1.198.127.2541.198.127.25516,382
271.198.128.0/181.198.128.1 to 1.198.191.2541.198.191.25516,382
281.198.192.0/181.198.192.1 to 1.198.255.2541.198.255.25516,382
291.199.0.0/181.199.0.1 to 1.199.63.2541.199.63.25516,382
301.199.64.0/181.199.64.1 to 1.199.127.2541.199.127.25516,382
311.199.128.0/181.199.128.1 to 1.199.191.2541.199.191.25516,382
321.199.192.0/181.199.192.1 to 1.199.255.2541.199.255.25516,382
331.200.0.0/181.200.0.1 to 1.200.63.2541.200.63.25516,382
341.200.64.0/181.200.64.1 to 1.200.127.2541.200.127.25516,382
351.200.128.0/181.200.128.1 to 1.200.191.2541.200.191.25516,382
361.200.192.0/181.200.192.1 to 1.200.255.2541.200.255.25516,382
371.201.0.0/181.201.0.1 to 1.201.63.2541.201.63.25516,382
381.201.64.0/181.201.64.1 to 1.201.127.2541.201.127.25516,382
391.201.128.0/181.201.128.1 to 1.201.191.2541.201.191.25516,382
401.201.192.0/181.201.192.1 to 1.201.255.2541.201.255.25516,382
411.202.0.0/181.202.0.1 to 1.202.63.2541.202.63.25516,382
421.202.64.0/181.202.64.1 to 1.202.127.2541.202.127.25516,382
431.202.128.0/181.202.128.1 to 1.202.191.2541.202.191.25516,382
441.202.192.0/181.202.192.1 to 1.202.255.2541.202.255.25516,382
451.203.0.0/181.203.0.1 to 1.203.63.2541.203.63.25516,382
461.203.64.0/181.203.64.1 to 1.203.127.2541.203.127.25516,382
471.203.128.0/181.203.128.1 to 1.203.191.2541.203.191.25516,382
481.203.192.0/181.203.192.1 to 1.203.255.2541.203.255.25516,382
491.204.0.0/181.204.0.1 to 1.204.63.2541.204.63.25516,382
501.204.64.0/181.204.64.1 to 1.204.127.2541.204.127.25516,382
511.204.128.0/181.204.128.1 to 1.204.191.2541.204.191.25516,382
521.204.192.0/181.204.192.1 to 1.204.255.2541.204.255.25516,382
531.205.0.0/181.205.0.1 to 1.205.63.2541.205.63.25516,382
541.205.64.0/181.205.64.1 to 1.205.127.2541.205.127.25516,382
551.205.128.0/181.205.128.1 to 1.205.191.2541.205.191.25516,382
561.205.192.0/181.205.192.1 to 1.205.255.2541.205.255.25516,382
571.206.0.0/181.206.0.1 to 1.206.63.2541.206.63.25516,382
581.206.64.0/181.206.64.1 to 1.206.127.2541.206.127.25516,382
591.206.128.0/181.206.128.1 to 1.206.191.2541.206.191.25516,382
601.206.192.0/181.206.192.1 to 1.206.255.2541.206.255.25516,382
611.207.0.0/181.207.0.1 to 1.207.63.2541.207.63.25516,382
621.207.64.0/181.207.64.1 to 1.207.127.2541.207.127.25516,382
631.207.128.0/181.207.128.1 to 1.207.191.2541.207.191.25516,382
641.207.192.0/181.207.192.1 to 1.207.255.2541.207.255.25516,382
651.208.0.0/181.208.0.1 to 1.208.63.2541.208.63.25516,382
661.208.64.0/181.208.64.1 to 1.208.127.2541.208.127.25516,382
671.208.128.0/181.208.128.1 to 1.208.191.2541.208.191.25516,382
681.208.192.0/181.208.192.1 to 1.208.255.2541.208.255.25516,382
691.209.0.0/181.209.0.1 to 1.209.63.2541.209.63.25516,382
701.209.64.0/181.209.64.1 to 1.209.127.2541.209.127.25516,382
711.209.128.0/181.209.128.1 to 1.209.191.2541.209.191.25516,382
721.209.192.0/181.209.192.1 to 1.209.255.2541.209.255.25516,382
731.210.0.0/181.210.0.1 to 1.210.63.2541.210.63.25516,382
741.210.64.0/181.210.64.1 to 1.210.127.2541.210.127.25516,382
751.210.128.0/181.210.128.1 to 1.210.191.2541.210.191.25516,382
761.210.192.0/181.210.192.1 to 1.210.255.2541.210.255.25516,382
771.211.0.0/181.211.0.1 to 1.211.63.2541.211.63.25516,382
781.211.64.0/181.211.64.1 to 1.211.127.2541.211.127.25516,382
791.211.128.0/181.211.128.1 to 1.211.191.2541.211.191.25516,382
801.211.192.0/181.211.192.1 to 1.211.255.2541.211.255.25516,382
811.212.0.0/181.212.0.1 to 1.212.63.2541.212.63.25516,382
821.212.64.0/181.212.64.1 to 1.212.127.2541.212.127.25516,382
831.212.128.0/181.212.128.1 to 1.212.191.2541.212.191.25516,382
841.212.192.0/181.212.192.1 to 1.212.255.2541.212.255.25516,382
851.213.0.0/181.213.0.1 to 1.213.63.2541.213.63.25516,382
861.213.64.0/181.213.64.1 to 1.213.127.2541.213.127.25516,382
871.213.128.0/181.213.128.1 to 1.213.191.2541.213.191.25516,382
881.213.192.0/181.213.192.1 to 1.213.255.2541.213.255.25516,382
891.214.0.0/181.214.0.1 to 1.214.63.2541.214.63.25516,382
901.214.64.0/181.214.64.1 to 1.214.127.2541.214.127.25516,382
911.214.128.0/181.214.128.1 to 1.214.191.2541.214.191.25516,382
921.214.192.0/181.214.192.1 to 1.214.255.2541.214.255.25516,382
931.215.0.0/181.215.0.1 to 1.215.63.2541.215.63.25516,382
941.215.64.0/181.215.64.1 to 1.215.127.2541.215.127.25516,382
951.215.128.0/181.215.128.1 to 1.215.191.2541.215.191.25516,382
961.215.192.0/181.215.192.1 to 1.215.255.2541.215.255.25516,382
971.216.0.0/181.216.0.1 to 1.216.63.2541.216.63.25516,382
981.216.64.0/181.216.64.1 to 1.216.127.2541.216.127.25516,382
991.216.128.0/181.216.128.1 to 1.216.191.2541.216.191.25516,382
1001.216.192.0/181.216.192.1 to 1.216.255.2541.216.255.25516,382
1011.217.0.0/181.217.0.1 to 1.217.63.2541.217.63.25516,382
1021.217.64.0/181.217.64.1 to 1.217.127.2541.217.127.25516,382
1031.217.128.0/181.217.128.1 to 1.217.191.2541.217.191.25516,382
1041.217.192.0/181.217.192.1 to 1.217.255.2541.217.255.25516,382
1051.218.0.0/181.218.0.1 to 1.218.63.2541.218.63.25516,382
1061.218.64.0/181.218.64.1 to 1.218.127.2541.218.127.25516,382
1071.218.128.0/181.218.128.1 to 1.218.191.2541.218.191.25516,382
1081.218.192.0/181.218.192.1 to 1.218.255.2541.218.255.25516,382
1091.219.0.0/181.219.0.1 to 1.219.63.2541.219.63.25516,382
1101.219.64.0/181.219.64.1 to 1.219.127.2541.219.127.25516,382
1111.219.128.0/181.219.128.1 to 1.219.191.2541.219.191.25516,382
1121.219.192.0/181.219.192.1 to 1.219.255.2541.219.255.25516,382
1131.220.0.0/181.220.0.1 to 1.220.63.2541.220.63.25516,382
1141.220.64.0/181.220.64.1 to 1.220.127.2541.220.127.25516,382
1151.220.128.0/181.220.128.1 to 1.220.191.2541.220.191.25516,382
1161.220.192.0/181.220.192.1 to 1.220.255.2541.220.255.25516,382
1171.221.0.0/181.221.0.1 to 1.221.63.2541.221.63.25516,382
1181.221.64.0/181.221.64.1 to 1.221.127.2541.221.127.25516,382
1191.221.128.0/181.221.128.1 to 1.221.191.2541.221.191.25516,382
1201.221.192.0/181.221.192.1 to 1.221.255.2541.221.255.25516,382
1211.222.0.0/181.222.0.1 to 1.222.63.2541.222.63.25516,382
1221.222.64.0/181.222.64.1 to 1.222.127.2541.222.127.25516,382
1231.222.128.0/181.222.128.1 to 1.222.191.2541.222.191.25516,382
1241.222.192.0/181.222.192.1 to 1.222.255.2541.222.255.25516,382
1251.223.0.0/181.223.0.1 to 1.223.63.2541.223.63.25516,382
1261.223.64.0/181.223.64.1 to 1.223.127.2541.223.127.25516,382
1271.223.128.0/181.223.128.1 to 1.223.191.2541.223.191.25516,382
1281.223.192.0/181.223.192.1 to 1.223.255.2541.223.255.25516,382
1291.224.0.0/181.224.0.1 to 1.224.63.2541.224.63.25516,382
1301.224.64.0/181.224.64.1 to 1.224.127.2541.224.127.25516,382
1311.224.128.0/181.224.128.1 to 1.224.191.2541.224.191.25516,382
1321.224.192.0/181.224.192.1 to 1.224.255.2541.224.255.25516,382
1331.225.0.0/181.225.0.1 to 1.225.63.2541.225.63.25516,382
1341.225.64.0/181.225.64.1 to 1.225.127.2541.225.127.25516,382
1351.225.128.0/181.225.128.1 to 1.225.191.2541.225.191.25516,382
1361.225.192.0/181.225.192.1 to 1.225.255.2541.225.255.25516,382
1371.226.0.0/181.226.0.1 to 1.226.63.2541.226.63.25516,382
1381.226.64.0/181.226.64.1 to 1.226.127.2541.226.127.25516,382
1391.226.128.0/181.226.128.1 to 1.226.191.2541.226.191.25516,382
1401.226.192.0/181.226.192.1 to 1.226.255.2541.226.255.25516,382
1411.227.0.0/181.227.0.1 to 1.227.63.2541.227.63.25516,382
1421.227.64.0/181.227.64.1 to 1.227.127.2541.227.127.25516,382
1431.227.128.0/181.227.128.1 to 1.227.191.2541.227.191.25516,382
1441.227.192.0/181.227.192.1 to 1.227.255.2541.227.255.25516,382
1451.228.0.0/181.228.0.1 to 1.228.63.2541.228.63.25516,382
1461.228.64.0/181.228.64.1 to 1.228.127.2541.228.127.25516,382
1471.228.128.0/181.228.128.1 to 1.228.191.2541.228.191.25516,382
1481.228.192.0/181.228.192.1 to 1.228.255.2541.228.255.25516,382
1491.229.0.0/181.229.0.1 to 1.229.63.2541.229.63.25516,382
1501.229.64.0/181.229.64.1 to 1.229.127.2541.229.127.25516,382
1511.229.128.0/181.229.128.1 to 1.229.191.2541.229.191.25516,382
1521.229.192.0/181.229.192.1 to 1.229.255.2541.229.255.25516,382
1531.230.0.0/181.230.0.1 to 1.230.63.2541.230.63.25516,382
1541.230.64.0/181.230.64.1 to 1.230.127.2541.230.127.25516,382
1551.230.128.0/181.230.128.1 to 1.230.191.2541.230.191.25516,382
1561.230.192.0/181.230.192.1 to 1.230.255.2541.230.255.25516,382
1571.231.0.0/181.231.0.1 to 1.231.63.2541.231.63.25516,382
1581.231.64.0/181.231.64.1 to 1.231.127.2541.231.127.25516,382
1591.231.128.0/181.231.128.1 to 1.231.191.2541.231.191.25516,382
1601.231.192.0/181.231.192.1 to 1.231.255.2541.231.255.25516,382
1611.232.0.0/181.232.0.1 to 1.232.63.2541.232.63.25516,382
1621.232.64.0/181.232.64.1 to 1.232.127.2541.232.127.25516,382
1631.232.128.0/181.232.128.1 to 1.232.191.2541.232.191.25516,382
1641.232.192.0/181.232.192.1 to 1.232.255.2541.232.255.25516,382
1651.233.0.0/181.233.0.1 to 1.233.63.2541.233.63.25516,382
1661.233.64.0/181.233.64.1 to 1.233.127.2541.233.127.25516,382
1671.233.128.0/181.233.128.1 to 1.233.191.2541.233.191.25516,382
1681.233.192.0/181.233.192.1 to 1.233.255.2541.233.255.25516,382
1691.234.0.0/181.234.0.1 to 1.234.63.2541.234.63.25516,382
1701.234.64.0/181.234.64.1 to 1.234.127.2541.234.127.25516,382
1711.234.128.0/181.234.128.1 to 1.234.191.2541.234.191.25516,382
1721.234.192.0/181.234.192.1 to 1.234.255.2541.234.255.25516,382
1731.235.0.0/181.235.0.1 to 1.235.63.2541.235.63.25516,382
1741.235.64.0/181.235.64.1 to 1.235.127.2541.235.127.25516,382
1751.235.128.0/181.235.128.1 to 1.235.191.2541.235.191.25516,382
1761.235.192.0/181.235.192.1 to 1.235.255.2541.235.255.25516,382
1771.236.0.0/181.236.0.1 to 1.236.63.2541.236.63.25516,382
1781.236.64.0/181.236.64.1 to 1.236.127.2541.236.127.25516,382
1791.236.128.0/181.236.128.1 to 1.236.191.2541.236.191.25516,382
1801.236.192.0/181.236.192.1 to 1.236.255.2541.236.255.25516,382
1811.237.0.0/181.237.0.1 to 1.237.63.2541.237.63.25516,382
1821.237.64.0/181.237.64.1 to 1.237.127.2541.237.127.25516,382
1831.237.128.0/181.237.128.1 to 1.237.191.2541.237.191.25516,382
1841.237.192.0/181.237.192.1 to 1.237.255.2541.237.255.25516,382
1851.238.0.0/181.238.0.1 to 1.238.63.2541.238.63.25516,382
1861.238.64.0/181.238.64.1 to 1.238.127.2541.238.127.25516,382
1871.238.128.0/181.238.128.1 to 1.238.191.2541.238.191.25516,382
1881.238.192.0/181.238.192.1 to 1.238.255.2541.238.255.25516,382
1891.239.0.0/181.239.0.1 to 1.239.63.2541.239.63.25516,382
1901.239.64.0/181.239.64.1 to 1.239.127.2541.239.127.25516,382
1911.239.128.0/181.239.128.1 to 1.239.191.2541.239.191.25516,382
1921.239.192.0/181.239.192.1 to 1.239.255.2541.239.255.25516,382
1931.240.0.0/181.240.0.1 to 1.240.63.2541.240.63.25516,382
1941.240.64.0/181.240.64.1 to 1.240.127.2541.240.127.25516,382
1951.240.128.0/181.240.128.1 to 1.240.191.2541.240.191.25516,382
1961.240.192.0/181.240.192.1 to 1.240.255.2541.240.255.25516,382
1971.241.0.0/181.241.0.1 to 1.241.63.2541.241.63.25516,382
1981.241.64.0/181.241.64.1 to 1.241.127.2541.241.127.25516,382
1991.241.128.0/181.241.128.1 to 1.241.191.2541.241.191.25516,382
2001.241.192.0/181.241.192.1 to 1.241.255.2541.241.255.25516,382
2011.242.0.0/181.242.0.1 to 1.242.63.2541.242.63.25516,382
2021.242.64.0/181.242.64.1 to 1.242.127.2541.242.127.25516,382
2031.242.128.0/181.242.128.1 to 1.242.191.2541.242.191.25516,382
2041.242.192.0/181.242.192.1 to 1.242.255.2541.242.255.25516,382
2051.243.0.0/181.243.0.1 to 1.243.63.2541.243.63.25516,382
2061.243.64.0/181.243.64.1 to 1.243.127.2541.243.127.25516,382
2071.243.128.0/181.243.128.1 to 1.243.191.2541.243.191.25516,382
2081.243.192.0/181.243.192.1 to 1.243.255.2541.243.255.25516,382
2091.244.0.0/181.244.0.1 to 1.244.63.2541.244.63.25516,382
2101.244.64.0/181.244.64.1 to 1.244.127.2541.244.127.25516,382
2111.244.128.0/181.244.128.1 to 1.244.191.2541.244.191.25516,382
2121.244.192.0/181.244.192.1 to 1.244.255.2541.244.255.25516,382
2131.245.0.0/181.245.0.1 to 1.245.63.2541.245.63.25516,382
2141.245.64.0/181.245.64.1 to 1.245.127.2541.245.127.25516,382
2151.245.128.0/181.245.128.1 to 1.245.191.2541.245.191.25516,382
2161.245.192.0/181.245.192.1 to 1.245.255.2541.245.255.25516,382
2171.246.0.0/181.246.0.1 to 1.246.63.2541.246.63.25516,382
2181.246.64.0/181.246.64.1 to 1.246.127.2541.246.127.25516,382
2191.246.128.0/181.246.128.1 to 1.246.191.2541.246.191.25516,382
2201.246.192.0/181.246.192.1 to 1.246.255.2541.246.255.25516,382
2211.247.0.0/181.247.0.1 to 1.247.63.2541.247.63.25516,382
2221.247.64.0/181.247.64.1 to 1.247.127.2541.247.127.25516,382
2231.247.128.0/181.247.128.1 to 1.247.191.2541.247.191.25516,382
2241.247.192.0/181.247.192.1 to 1.247.255.2541.247.255.25516,382
2251.248.0.0/181.248.0.1 to 1.248.63.2541.248.63.25516,382
2261.248.64.0/181.248.64.1 to 1.248.127.2541.248.127.25516,382
2271.248.128.0/181.248.128.1 to 1.248.191.2541.248.191.25516,382
2281.248.192.0/181.248.192.1 to 1.248.255.2541.248.255.25516,382
2291.249.0.0/181.249.0.1 to 1.249.63.2541.249.63.25516,382
2301.249.64.0/181.249.64.1 to 1.249.127.2541.249.127.25516,382
2311.249.128.0/181.249.128.1 to 1.249.191.2541.249.191.25516,382
2321.249.192.0/181.249.192.1 to 1.249.255.2541.249.255.25516,382
2331.250.0.0/181.250.0.1 to 1.250.63.2541.250.63.25516,382
2341.250.64.0/181.250.64.1 to 1.250.127.2541.250.127.25516,382
2351.250.128.0/181.250.128.1 to 1.250.191.2541.250.191.25516,382
2361.250.192.0/181.250.192.1 to 1.250.255.2541.250.255.25516,382
2371.251.0.0/181.251.0.1 to 1.251.63.2541.251.63.25516,382
2381.251.64.0/181.251.64.1 to 1.251.127.2541.251.127.25516,382
2391.251.128.0/181.251.128.1 to 1.251.191.2541.251.191.25516,382
2401.251.192.0/181.251.192.1 to 1.251.255.2541.251.255.25516,382
2411.252.0.0/181.252.0.1 to 1.252.63.2541.252.63.25516,382
2421.252.64.0/181.252.64.1 to 1.252.127.2541.252.127.25516,382
2431.252.128.0/181.252.128.1 to 1.252.191.2541.252.191.25516,382
2441.252.192.0/181.252.192.1 to 1.252.255.2541.252.255.25516,382
2451.253.0.0/181.253.0.1 to 1.253.63.2541.253.63.25516,382
2461.253.64.0/181.253.64.1 to 1.253.127.2541.253.127.25516,382
2471.253.128.0/181.253.128.1 to 1.253.191.2541.253.191.25516,382
2481.253.192.0/181.253.192.1 to 1.253.255.2541.253.255.25516,382
2491.254.0.0/181.254.0.1 to 1.254.63.2541.254.63.25516,382
2501.254.64.0/181.254.64.1 to 1.254.127.2541.254.127.25516,382
2511.254.128.0/181.254.128.1 to 1.254.191.2541.254.191.25516,382
2521.254.192.0/181.254.192.1 to 1.254.255.2541.254.255.25516,382
2531.255.0.0/181.255.0.1 to 1.255.63.2541.255.63.25516,382
2541.255.64.0/181.255.64.1 to 1.255.127.2541.255.127.25516,382
2551.255.128.0/181.255.128.1 to 1.255.191.2541.255.191.25516,382
2561.255.192.0/181.255.192.1 to 1.255.255.2541.255.255.25516,382

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.