Tire Size Calculator

Current Tire Size: New Tire Size:

This Tire Size Calculator helps you compare the difference between your current tire size and a new tire size. Here’s how it works:

Input Current and New Tire Sizes: Enter the current tire size (e.g., 215/60R16) and the new tire size (e.g., 225/65R17) into the respective input fields.
Calculate Tire Difference: Click the “Calculate Tire Difference” button to compute the percentage difference in diameter between the current and new tires.
View Results: The calculator will display the percentage difference in diameter and the estimated speedometer error caused by the difference.
About Tire Sizes: Tire sizes are typically expressed as width/aspect ratio R rim size (e.g., 215/60R16). The width is the width of the tire in millimeters, the aspect ratio is the height of the sidewall as a percentage of the width, and the rim size is the diameter of the rim in inches.
Calculation Method: The calculator parses the input tire sizes, calculates the diameter for both the current and new tires, and then computes the percentage difference in diameter. It also estimates the speedometer error caused by the diameter difference.
Note: The speedometer error estimation is simplified and may not be accurate for all vehicles. Consult your vehicle manufacturer or a professional for precise adjustments.
Usage: This calculator is useful when considering changing tire sizes to maintain accurate speedometer readings and overall vehicle performance.
FAQ:
- Q: Why is it important to consider tire size differences?
  - A: Changing tire sizes can affect your vehicle’s speedometer accuracy, handling, fuel efficiency, and overall performance.
- Q: How do I interpret the speedometer error?
  - A: The speedometer error indicates the percentage by which your speedometer may be inaccurate due to the tire size difference.
- Q: Can this calculator be used for all tire size conversions?
  - A: This calculator is primarily designed to compare differences between two tire sizes. For detailed tire size conversions and recommendations, consult with a tire specialist or refer to your vehicle’s manual.