1. What is a Tire Size To Gear Ratio Calculator?

Definition: This calculator estimates the gear ratio based on tire diameter and a constant value.

Purpose: It helps automotive enthusiasts and mechanics determine the optimal gear ratio for different tire sizes.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( GR \) — Gear ratio (unitless)
• \( Constant \) — Typically 336 (for mph/rpm calculations)
• \( TD \) — Tire diameter (inches)

Explanation: The constant is divided by tire diameter to determine the gear ratio needed to maintain similar performance characteristics when changing tire sizes.

3. Importance of Gear Ratio Calculation

Details: Proper gear ratio ensures optimal engine performance, fuel efficiency, and drivability when changing tire sizes.

4. Using the Calculator

Tips: Enter the constant (default 336) and tire diameter in inches. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is the 336 constant?
A: It's derived from (60 * 5280) / (π * 12 * 1000) to convert rpm to mph with tire diameter in inches.

Q2: How do I measure tire diameter?
A: Measure from ground to top of tire when properly inflated or use manufacturer specifications.

Q3: When would I change the constant?
A: You might adjust it for different units (e.g., km/h instead of mph) or specific vehicle requirements.

Q4: Does this work for all vehicles?
A: The formula works for most vehicles but may need adjustment for extreme tire sizes or specialized applications.

Q5: How precise is this calculation?
A: It provides a good estimate but actual performance may vary based on transmission, torque curve, and other factors.