I actually wrote this program when I was a sophomore in high school, which was before I found this site, so the molar masses of individual elements may not reflect the WebElements periodic table exactly. All the same, it's highly accurate.

To operate the calculator, just open the program. The periodic table is set up in the form of buttons, one per element. Click on the button of an element once for each time it is used in a formula, and in a text box at the bottom will be the mass of 1 mole of that substance. Click Clear to clear the box (don't just delete the contents).

In the unlikely case that you use an old (c. 2000) version of Norton or perhaps any version of AVG Anti-Virus, the program may come across as a virus. Ignore it.

Technical reason these scanners pick up the program: this program was compiled with Rapid-Q, which compiles to an interpeter EXE with some sort of P-code tacked on. One kind soul wrote a virus in Rapid-Q, and the definitions for this virus in the aforementioned scanners is based on the header section of the virus's EXE instead of what makes the program unique, which happens to be the code common to every Rapid-Q EXE in existance. In essence, it detects fundamental aspects of a Rapid-Q EXE and declares it a virus. So don't worry; it's not really a virus.

The URL for the program (needs Winzip or similar):
rpi.edu/~devina/fmc.zip