Tire Diameter Calculator
Calculate the overall diameter of a tire.
Overall Diameter (inches): -
Use this tire diameter calculator, tire size calculator, tire dimension calculator, wheel diameter calculator, tyre diameter calculator calculator for quick, clear estimates. Try a tiny example to see the impact of each input.
Frequently Asked Questions
Q: How do tire size numbers work?
Tire size numbers (e.g., P205/65R15) typically indicate the tire type (P for passenger), tread width in millimeters (205), aspect ratio (65, the sidewall height as a percentage of width), construction type (R for radial), and rim diameter in inches (15).
Why is tire diameter important?
Tire diameter is important because it affects speedometer accuracy, gear ratio, ground clearance, and overall vehicle performance. Changes in diameter can lead to incorrect speed readings and altered handling characteristics.
How does tire diameter affect speedometer readings?
Changing tire diameter from the vehicle’s original specifications will affect speedometer readings. A larger diameter tire will make the speedometer read slower than the actual speed, while a smaller diameter tire will make it read faster.
What is rolling circumference?
Rolling circumference refers to the effective distance a tire travels in one full rotation under load, which is a crucial factor in vehicle dynamics and speedometer calibration.