Address (Host or Network) Netmask (i.e. 24) Netmask for sub/supernet (optional)
/ move to:
  



Address:   189.12.0.0            10111101.0000110 0.00000000.00000000
Netmask:   255.254.0.0 = 15      11111111.1111111 0.00000000.00000000
Wildcard:  0.1.255.255           00000000.0000000 1.11111111.11111111
=>
Network:   189.12.0.0/15         10111101.0000110 0.00000000.00000000 (Class B)
Broadcast: 189.13.255.255        10111101.0000110 1.11111111.11111111
HostMin:   189.12.0.1            10111101.0000110 0.00000000.00000001
HostMax:   189.13.255.254        10111101.0000110 1.11111111.11111110
Hosts/Net: 131070

Thanks to http://www.netzwerkinfo.de/daemons/ for this ip calculator icon :-)
Version 0.35.2 2005/07/07
Download
07/27/2006 Security information
Screenshot (ipcalc works also at the prompt)
CGI wrapper that produced this page.
Archive
Have a look in the archives for the new version 0.41, with the capability to deaggregate network ranges
How to run this under windows
Debian users can apt-get install ipcalc
2000-2006 Krischan Jodies