There are a nice set of on-line calculators available on the Jack Anderson's High Power site. These calculators use VBScript, and so only work with Mirosoft's Internet Explorer.
I also have received a few suggestions for a stand-alone version of the calculators (not online). I have finished making a desktop version and it now posted to my web site for download: www.rockethead.net/Downloads/RocketryTools.zip
It is freeware and I do not ask for or expect any payment from those who download it. It is a standard .zip file, to install the program you would need to unzip and then run setup.exe.
Submitted by Jack Anderson