EV Gear Ratio Calculator
The EV Gear Ratio Calculator determines the optimal reduction ratio by matching motor RPM to wheel speed at a given vehicle speed. The gear ratio defines how many motor revolutions are required to turn the wheels once, directly influencing wheel torque and top speed.
Enter the Motor Speed, Wheel Diameter and the Vehicle Speed to calculate the gear ratio for a single-speed EV transmission.
This Gear Ratio Calculator helps optimize an EV’s drivetrain by using inputs such as motor speed, wheel diameter, and target vehicle speed to accurately determine the ideal gear ratio. By matching motor speed to wheel speed, it ensures efficient power delivery and improved vehicle performance at the desired operating conditions.
For example:
If the Motor Speed is 8000 RPM, Wheel Diameter is 0.6 meters, and Vehicle Speed is 30 m/s (108 km/h),
Wheel Circumference = π × 0.6 ≈ 1.885 m
Wheel Speed = (30 m/s) / (1.885 m) ≈ 15.9 rps × 60 ≈ 954 RPM
Gear Ratio = 8000 / 954 ≈ 8.38
Thus, the Gear Ratio should be about 8.38:1 to perfectly match motor speed to wheel speed at 30 m/s.
