## Introduction:

Are you puzzled by the cryptic numbers and letters on your car’s tires? Fear not! Our tire size calculator is here to demystify the tire code and help you compare different tire sizes. In this guide, we’ll walk you through how tire sizes work, decipher the tire code, and explain how to use our calculator for precise measurements.

## How Tire Sizes Work:

Tire Code Breakdown:

• The first letter indicates the tire’s intended use (e.g., P for Passenger car).
• A 3-digit number signifies the tire width in millimeters.
• A slash separates the width from the profile ratio, indicating sidewall height as a percentage.
• An optional letter reveals tire construction type (R for radial).
• The final number represents the wheel diameter in inches.

## How to Calculate Tire Size:

1. Sidewall Height: Multiply the profile ratio by the tire width and divide by 100.
• Formula: Sidewall height = profile ratio × width / 100
2. Tire Diameter: Add twice the sidewall height to the wheel diameter.
• Formula: Tire diameter = wheel diameter + (2 × sidewall height)
3. Circumference: Use the circle equation.
• Formula: Circumference = π × diameter
4. Revolutions per Mile: Calculate using the converted mile and tire circumference.
• Formula: Revolutions = 63360 / circumference

## How to Use the Tire Size Calculator:

1. Enter tire width, profile ratio, and wheel size.
2. Optionally specify tire construction type.
3. View the calculated tire diameter, sidewall height, circumference, and revolutions per mile.
4. Compare with another tire by selecting “Yes.”
5. Check the absolute difference in diameters and percentage change.

## Example Tire Size Comparison:

• Compare two tires with codes 195/65R15 and 195/85R15.
• Calculate the diameter difference and percentage change.
• Evaluate if the difference is within the recommended 2.5% range.

## FAQ:

1. How to Read Tire Size: Understand the letters and numbers on the sidewall to determine tire type, width, aspect ratio, construction, and rim diameter.
2. Tire Lifespan: Tires typically last 6 to 10 years, depending on factors like quality and maintenance.
3. Changing a Tire: Follow steps such as finding a safe spot, gathering tools, lifting the car with a jack, and replacing the tire.
4. Tire Date Code: The number 2023 indicates the tire was produced in May 2023, with the first two digits representing the week of the year.

Conclusion: Armed with this knowledge, use our tire size calculator to make informed decisions about your vehicle’s tires. Whether comparing sizes or understanding tire codes, this guide equips you for a smoother ride. Explore the world of tire sizes with confidence!