Calculate Top Speed by RPM

Enter Maximum Safe Engine RPM
Enter Tire Size Diameter
Enter Differential Gear Ratio :1
Enter Transmission Gear Ratio :1
Potential Calculated Vehicle Speed

Please provide the maximum RPM for the engine, the diameter of the tire size, as well as the differential gear ratio and the transmission gear ratio. Once entered, click the "Calculate Potential Speed" button. The calculated potential speed will be displayed in both miles per hour and kilometers per hour.

How do you calculate speed from RPM?

To calculate the speed from RPM (revolutions per minute), you need to multiply the circumference of the object by its angular speed in RPM. The formula is as follows:

Speed = Circumference × RPM

The resulting speed will depend on the units used for the circumference and RPM. If you have the circumference in inches and the RPM, the speed will be in inches per minute. If you want to convert it to another unit, such as miles per hour or kilometers per hour, you will need to convert the units accordingly.

For example, let's say the circumference of the object is 87.98 inches and it rotates at 400 RPM. To calculate the surface speed in inches per minute:

Speed = 87.98 inches × 400 RPM = 35,192 inches per minute

To convert this to a different unit, such as miles per hour or kilometers per hour, you would need to perform additional calculations, considering factors like unit conversions and time.

How do you calculate speed with rpm and gear ratio?

To calculate the speed using RPM (revolutions per minute) and gear ratio, you can use the following formula:

Speed = (RPM * Tire Circumference) / (Gear Ratio * Final Drive Ratio)

Here's an explanation of the terms involved:

  1. RPM: The engine speed in revolutions per minute.
  2. Tire Circumference: The distance traveled by one complete revolution of the tire. It is calculated as the product of the tire diameter and π (pi) (Circumference = π * Diameter).
  3. Gear Ratio: The ratio between the number of teeth on the input gear (driven by the engine) and the output gear (connected to the wheels).
  4. Final Drive Ratio: The ratio between the input shaft (driven by the transmission) and the output shaft (connected to the wheels). It takes into account additional gear ratios within the differential.

By plugging in the values for RPM, Tire Circumference, Gear Ratio, and Final Drive Ratio into the formula, you can calculate the speed.

It's important to note that the tire circumference should be in the same unit as the final desired speed (e.g., inches for inches per minute or miles for miles per hour). Also, make sure the gear ratios are properly expressed (e.g., as 3.73:1 or 0.73:1) to maintain accuracy in the calculation.