Best gear ratio calculator!
The program can be downloaded from http://jimsitton.net/ratiocalc/
Just right click on the file gearratio.exe
and select "save link as" and put it somewhere you can find it again.
Once it's saved, double click on the gearratio.exe file and it will run.
The program allows for up to three ratios in series.
If you have fewer just leave the unused ratios set to 1:1.
The program will also calculate speed based on
Be sure to measure the outside diameter of your wheel for accurate results.