Transmission Ratio Calculator

Calculate overall transmission ratio, wheel torque, and vehicle speed for any gear combination in the drivetrain.

Input Parameters

Results

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Overall Ratio
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Wheel Torque
lb-ft
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Tractive Force
lbs
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Vehicle Speed
mph
Note: Typical manual transmission efficiency is 92-97%. Automatic transmissions are 85-92%. Higher overall ratios multiply torque but reduce top speed. SAE J1510 gear ratio standards.

Reference

Overall Ratio = Gear_ratio × Final_drive Wheel Torque = Engine_torque × Overall × Efficiency (92%) Tractive Force = Wheel_torque × 12 / Tire_radius Wheel RPM = Engine_RPM / Overall Vehicle Speed = Wheel_RPM × Tire_circ × 60 / 5280