RPM and MPH Computator By Bowling

The following simple computation determines engine RPM at a given MPH, or MPH at a given RPM. Tire diameter, final (differential) gear ratio, and transmission ratio (usually 1.0 for high gear, or something like 0.7 for overdrive). Simple calculation, but saves one from breaking out the calculator.

Program Inputs:

Final Gear Ratio:

Transmission Gearing Ratio:

Tire Diameter in Inches:

Want to Compute:

Engine RPM:

Vehicle Road Speed:

Press this button to submit a computation:

To reset the form input:

Bruce Bowling
Bowling Superior