Gear ratio calculator for your Chevrolet
This will help you pick the right size tires, transmission and gear ratio combination for your classic.
      Enter MPH Enter RPM
  Gear Ratio Motor MPH Car RPM
  First RPM MPH
  Second RPM MPH
  Third RPM MPH
  Forth RPM MPH
  Fifth RPM MPH
  Sixth RPM MPH

Vehicle Information
Numbers must be entered as decimals, example 71 1/4" would be entered as 71.25.

Enter your tire size (the diameter may vary slightly depending on the manufacture if in doubt use manufactures posted diameter)

Metric width or Enter Rear Tire Diameter ----> Rear
Profile or Enter Rear Tire Diameter ---->
Rim diameter or Enter Rear Tire Diameter ---->
Effective tire diameter
The tire diameter is less with a load (effective tire diameter = diameter x 0.94)
Pick your rear end gear ratio
Select your transmission