Gear Ratio Speed Calculator

Gear Ratio Speed Formula:

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

Vehicle Speed:

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1. What is Gear Ratio Speed Calculation?

The Gear Ratio Speed calculation determines vehicle speed based on engine RPM, gear ratio, and tire size. It's essential for automotive enthusiasts, mechanics, and engineers to understand vehicle performance characteristics.

2. How Does the Calculator Work?

The calculator uses the gear ratio speed formula:

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

Where:

\( RPM \) — Engine revolutions per minute
\( Tire\,Circumference \) — Tire diameter × π (3.1416)
\( Gear\,Ratio \) — Transmission gear ratio
\( 336 \) — Conversion constant (combining unit conversions)

Explanation: The formula converts rotational speed to linear speed accounting for gear reduction and tire size.

3. Importance of Gear Ratio Speed Calculation

Details: Understanding the relationship between RPM and speed helps in gear selection, performance tuning, and fuel efficiency optimization.

4. Using the Calculator

Tips: Enter engine RPM, gear ratio, and tire diameter in inches. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the 336 constant in the formula?
A: It combines unit conversions (5280 feet/mile, 12 inches/foot, 60 minutes/hour) into one constant: (5280 × 12) ÷ (60 × π) ≈ 336.

Q2: How accurate is this calculation?
A: It provides theoretical speed. Actual speed may vary due to tire slippage, transmission losses, and other factors.

Q3: Can I use this for any vehicle?
A: Yes, it works for cars, trucks, motorcycles - any wheeled vehicle if you know the correct parameters.

Q4: What if I know tire circumference instead of diameter?
A: You can modify the formula to use circumference directly instead of calculating it from diameter.

Q5: How does gear ratio affect speed?
A: Higher gear ratios (numerically lower) result in higher speeds at the same RPM, while lower ratios (numerically higher) provide more torque but lower speed.