Gear Ratio Calculator

Use this calculator to determine your gear ratio and vehicle’s speed in any gear and any engine RPM for best performance.

Scroll through the list of popular transmissions to find yours. Or, change input variables (engine RPM, axle gear ratio and tire height) to determine vehicle speed in each forward gear.

For the Tire Height field, enter your tire diameter in inches. For more information, read “What’s on your tire’s sidewall,

As an added bonus, the Gear Ratio Calculator doubles as a Vehicle Speed Calculator.

TREMEC gears
Select Transmission:
Engine RPM: Enter your desired RPM for racing or cruising here.
Axle Ratio: Enter your rear axle ratio here.
Tire Height (in): Enter your tire height here. Use the Aspect Ratio calculator below if you do not know your tire height.
  Ratio MPH  
1st Gear The estimated speed you will be traveling based on the parameters you established and the transmission you selected.
2nd Gear
3rd Gear  
4th Gear  
5th Gear  
6th Gear  

TREMEC ASPECT RATIO CALCULATOR: Find your tire height using this calculator.

Enter the tire width in millimeters, the aspect ratio, the wheel diameter in inches, and Click on Calculate
Tire Width (mm) Wheel Diameter (in)
Aspect Ratio (1-100)
Tire Height (in) Tire Width (in)