1. What is Tire Circumference?

Tire circumference is the distance around the outside of a tire. It's important for calculating speedometer accuracy, gear ratios, and overall vehicle performance.

2. How Does the Calculator Work?

The calculator uses the circumference formula:

Where:

• \( C \) — Circumference (inches)
• \( \pi \) — Approximately 3.14159
• \( d \) — Diameter (inches)

Explanation: The formula calculates the distance around a circle (tire) using its diameter.

3. Importance of Tire Circumference

Details: Accurate circumference measurement is crucial for proper speedometer calibration, odometer accuracy, and maintaining correct gear ratios.

4. Using the Calculator

Tips: Enter the tire diameter in inches. Measure from ground to top of tire when properly inflated and under load for most accurate results.

5. Frequently Asked Questions (FAQ)

Q1: How do I measure tire diameter?
A: Measure from the ground to the top of the tire when properly inflated and under the vehicle's weight.

Q2: Why is circumference important for speedometers?
A: Speedometers calculate speed based on how many times the tire rotates per minute. Incorrect circumference leads to speedometer error.

Q3: Does tire pressure affect circumference?
A: Yes, underinflated tires have slightly smaller circumference while overinflated tires have slightly larger circumference.

Q4: How does circumference affect gear ratio?
A: Larger circumference acts like a higher gear ratio, while smaller circumference acts like a lower gear ratio.

Q5: Can I use this for bicycle tires?
A: Yes, the formula works for any circular tire, though bicycle tires are often measured by ISO size (e.g., 700c).