1. What is a Gear Ratio To Speed Calculator?

Definition: This calculator estimates vehicle speed based on engine RPM, tire diameter, and gear ratio.

Purpose: It helps automotive enthusiasts and mechanics determine theoretical vehicle speed for given drivetrain parameters.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( S \) — Vehicle speed (mph)
• \( RPM \) — Engine revolutions per minute
• \( TD \) — Tire diameter (inches)
• \( GR \) — Gear ratio (unitless)
• \( \pi \) — Pi (approximately 3.1416)
• 1056 — Conversion factor for units

Explanation: The formula calculates how far the vehicle travels per minute based on wheel rotation, then converts to miles per hour.

3. Importance of Gear Ratio Calculations

Details: Understanding gear ratios helps optimize vehicle performance, fuel efficiency, and towing capability.

4. Using the Calculator

Tips: Enter engine RPM, tire diameter in inches, and gear ratio. All values must be > 0. Measure tire diameter accurately for best results.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical gear ratio?
A: Common ratios range from 2.73 for highway efficiency to 4.10 for performance/towing vehicles.

Q2: How do I measure tire diameter?
A: Measure from ground to top of tire (loaded) or calculate from tire size markings (e.g., 275/60R15).

Q3: Does this account for torque converter slip?
A: No, this is theoretical speed. Automatic transmissions may show slightly lower actual speeds.

Q4: What's the 1056 constant?
A: It converts inches per minute to miles per hour (12 in/ft × 5280 ft/mile ÷ 60 min/hour).

Q5: How accurate is this calculation?
A: It's theoretical. Actual speed varies with tire wear, load, traction, and transmission efficiency.