jpilot's Gear Ratio Calculator -



I wrote a little gear ratio calculator that some might find handy. The program can be downloaded from 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 engine RPM, drive ratio,and wheel diameter. Be sure to measure the outside diameter of your wheel for accurate results.

If you have any questions post them in this thread.

Have fun!


Well-Known Member
May 2, 2007
Quick and simple, this program helped me gear my shifter bike properly.

One can open multiple instances of it to get ratios for multispeed bikes. Easy to use with internally-geared hubs, too.