RPM Metric Calculator, tire height calculator, gear ratio calculator

Gear Ratio Engine RPM Calculator


Ring Gear and Pinion Ratio
ex: 4.10
Tire Height
Calculated Results All Transmissions
without Overdrive
with Overdrive
Manual - 3 & 4 Speed
High Gear
Manual - 5 & 6 Speed
High Gear
Late Model Tacoma & Tundra

Transmission Final Gear Ratio Manual Entry


Ring Gear and Pinion Ratio
ex: 4.10
Tire Height
ex: 88cm
Transmission Final Gear Ratio
ex: 2.54
Calculated Results
Engine RPM

* auto = D in an AOD (1:1)
* AOD is calculated at .70 transmission ratio
* 5 speed is calculated at .80 transmission ratio
* Many late model vehicles have a taller overdrive ratio, such as Toyota Tacoma & Tundra with 6 speed Auto have a .58:1 overdrive.
Use 1:1 RPM x .58 = RPM

Recommended RPM @ 96kph
4 cyl 2200-3200
6 cyl 2000-3000
small block 1800-2800
big block 1600-2600
GM Duramax 6.6L 1800-2800
Ford Powerstroke
Ford Powerstroke (turbo) 1400-2200
Dodge Cummins Diesel 1400-2200

This is set to calculate Metric specifications. Our Imperial (US calculator is here

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These calculators are designed to give the approximate engine RPM (revolutions per minute) based on the ring gear and pinion gear ratio, the height of the tires (diameter from ground to top of the tire while mounted on the vehicle) and the transmission final gear ratio.

This calculator does not take into consideration any drive train loss, road and weather conditions or driver skills. The calculated results are displayed; the higher the engine RPM, the greater the potential speed at the cost of fuel, heat, friction and engine longevity. The results are only an Estimate - Your Mileage May Vary.