Auto Speed Calculator Mph

Auto Speed Formula:

\[ MPH = \frac{(RPM \times Tire\ Circumference)}{(Gear\ Ratio \times 336)} \]

Speed (MPH):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the Auto Speed Formula?

The Auto Speed Formula calculates vehicle speed in miles per hour (MPH) based on engine RPM, tire circumference, and gear ratio. It provides an accurate estimation of vehicle speed under specific mechanical conditions.

2. How Does the Calculator Work?

The calculator uses the Auto Speed Formula:

\[ MPH = \frac{(RPM \times Tire\ Circumference)}{(Gear\ Ratio \times 336)} \]

Where:

\( RPM \) — Engine revolutions per minute
\( Tire\ Circumference \) — Tire circumference in inches
\( Gear\ Ratio \) — Gear ratio (number)
\( 336 \) — Constant conversion factor

Explanation: The formula accounts for the relationship between engine speed, tire size, and gear ratio to determine vehicle speed.

3. Importance of Auto Speed Calculation

Details: Accurate speed calculation is crucial for vehicle performance analysis, gear ratio optimization, and understanding the relationship between engine RPM and actual vehicle speed.

4. Using the Calculator

Tips: Enter RPM in revolutions per minute, tire circumference in inches, and gear ratio as a number. All values must be valid positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why is 336 used in the formula?
A: The constant 336 is derived from unit conversions that transform the result into miles per hour.

Q2: How do I measure tire circumference?
A: Tire circumference can be measured directly or calculated from tire size specifications. It represents the distance the tire covers in one complete revolution.

Q3: What affects the accuracy of this calculation?
A: Tire wear, inflation pressure, transmission efficiency, and actual vs. theoretical gear ratios can affect accuracy.

Q4: Can this formula be used for different units?
A: The formula is specifically designed for RPM (rev/min), tire circumference (inches), and results in MPH. Unit conversions would be needed for different measurement systems.

Q5: Is this calculation applicable to all vehicles?
A: This formula works for most wheeled vehicles but may need adjustments for vehicles with continuously variable transmissions or other specialized drive systems.