1. What is an RPM Calculator?

Definition: This calculator determines the revolutions per minute (RPM) of a vehicle's wheels based on its speed and tire diameter.

Purpose: It helps automotive professionals, engineers, and enthusiasts understand wheel rotation rates at different speeds.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( RPM \) — Revolutions per minute
• \( S \) — Speed in miles per hour (mph)
• \( TD \) — Tire diameter in inches
• 1056 — Conversion factor (5280 feet/mile × 12 inches/foot ÷ 60 minutes/hour)

Explanation: The formula converts speed to inches per minute, then divides by tire circumference to get rotations per minute.

3. Importance of RPM Calculation

Details: Knowing wheel RPM helps in gear ratio selection, fuel efficiency analysis, and performance tuning.

4. Using the Calculator

Tips: Enter vehicle speed in mph and tire diameter in inches. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: How do I measure tire diameter accurately?
A: Measure from ground to top of tire (loaded) or use manufacturer specifications.

Q2: Why is the conversion factor 1056?
A: It converts mph to inches per minute (5280 ft/mile × 12 in/ft ÷ 60 min/hr).

Q3: Does this account for tire wear?
A: No, as tires wear down, their diameter decreases slightly, affecting RPM.

Q4: Can I use this for different wheel sizes?
A: Yes, just input the correct tire diameter for each wheel configuration.

Q5: How does RPM relate to engine RPM?
A: Wheel RPM multiplied by gear ratio equals engine RPM (in top gear).