Hey again jgrey29
,The website will have a copy of the calculator for use on the website.
Yes, so if you choose you like the idea of a website hosting your application then it'll be convenient for most users who will just need to navigate to your site and make use of your program straight away and may even be able to make use of it from a smartphone. Another advantage that you may find interesting is that every time a user requires the use of your program they will have navigate to your site leaving opportunity for you to keep your users up-to-date on the latest news and promoting other applications you might also want to host.
For someone who wants to download the program for use on their computer without the website, they will need .NET 2.0 or higher and they
will be fine. For people who don't have .Net 2.0 they can download the java calculator I already have and they will be fine
if they have java installed.

Yes, so if you decide you going to use Visual Studio (Eg, VB or Visual C++) your users will just require the .NET 2.0 Framework or higher. And yes, they'll be fine to download the Java version if they are comfortable with installing a Java Runtime or already have the runtime on their PC. I think as long as you can keep a fine line between all your versions of the program, you and your users should be fine. Cause you don't want to confused them with like 5 different versions of the same program.
Also, I found a hosting company that supports ASP.NET 2.0, is that what the calculator on the site will
need to function properly?
Well it depends if you want to write your program is ASP; If you do happen to write your
desktop application in VB or C# that comes with Visual Studio you should be able to copy over most of the code into ASP without any issues (Excluding graphical components), but just be aware if you do write it in Visual C++ you may have to change some syntax in order to get it to function properly in ASP, because as far as I know ASP only support VB and C#. But yes if you are planning on using Visual Studio you will require a server (host) that is running Windows Server on it as only Windows servers/pc's support the .NET Framework. It sounded like you said the .net framework could be packaged with the program. Does that mean the Body fat calculator
would include a version of .NET framework? how large would the file be? If they already had a version of .NET installed on their
system, would it hurt anything? That would solve the whole problem 
Yes, if you like when you creating a installer you could package the Framework required along with all other prerequisites your program needs with your application. But as you may have already guessed, this would indeed increase the file size quite substantially! If you package the Framework with your application and the user already has .NET installed, then no, it wouldn't affect them at all except for having to download a larger file than necessary. A way of going about solving this very issue, because we can easily assume that majority of users on the Internet already have some version of the .NET Framework installed is by allowing users to download your bare application (Without any packages) and make them aware that one of the prerequisites is .NET and if they don't already have it installed can download the Framework separately from Microsoft or you can even put the Framework for download on your site.

I hope that answered most of your questions. Do keep us updated...
Peace Out