1. What is Metric Tire Size?

The metric tire size system is the most common sizing system used worldwide. It provides three key measurements: width in millimeters, aspect ratio as a percentage, and rim diameter in inches.

2. How Does the Calculator Work?

The calculator uses the metric tire formula:

Where:

• \( \text{Width} \) — Tire width in millimeters (e.g., 205 in 205/55R16)
• \( \text{Aspect Ratio} \) — Sidewall height as percentage of width (e.g., 55 in 205/55R16)

Explanation: The aspect ratio represents the sidewall height as a percentage of the tire's width. A lower aspect ratio means a shorter sidewall.

3. Importance of Tire Size Calculation

Details: Calculating tire dimensions is crucial for proper vehicle fitment, maintaining speedometer accuracy, and ensuring optimal handling characteristics.

4. Using the Calculator

Tips: Enter the tire width in millimeters and aspect ratio as a percentage (without the % sign). Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What does the aspect ratio mean?
A: The aspect ratio is the height of the tire's sidewall expressed as a percentage of the tire's width.

Q2: How does tire size affect performance?
A: Wider tires typically provide better grip but may reduce fuel efficiency. Lower aspect ratios generally improve handling but may reduce ride comfort.

Q3: What is the complete metric tire size format?
A: The full format is Width/AspectRatioRimDiameter (e.g., 205/55R16), where R stands for radial construction.

Q4: Can I change my tire size?
A: You can change sizes within limits, but the overall diameter should remain similar to maintain speedometer accuracy and vehicle dynamics.

Q5: Where can I find my current tire size?
A: The size is molded into the sidewall of your tire, usually in the format: XXX/XXRXX (e.g., 205/55R16).