Tire Size Calculator
Calculate and understand your tire dimensions with our easy-to-use and free tool
Why Use Our Calculator?
Accurate Results
Get precise calculations for all tire dimensions
Easy Comparison
Compare different tire sizes side by side
Detailed Info
Understand all aspects of tire sizing
Frequently Asked Questions
What is a tire size calculator?
A tire size calculator is a tool that helps you understand and convert tire measurements. It can calculate dimensions like overall diameter, sidewall height, and circumference based on tire size specifications (e.g., 265/70R17).
How do I read tire sizes?
Tire sizes (e.g., 265/70R17) consist of three main numbers: the width in millimeters (265), the aspect ratio (70, representing sidewall height as a percentage of width), and the wheel diameter in inches (17). The 'R' indicates radial construction.
Why is tire size important?
Correct tire sizing is crucial for vehicle performance, safety, and accuracy of your speedometer. It affects handling, fuel efficiency, and ensures proper fitment without rubbing against vehicle components.
Can I use different tire sizes on my vehicle?
While some variation is possible, it's important to stay within manufacturer-recommended sizes. Significant changes can affect vehicle handling, speedometer accuracy, and clearance. Use our calculator to compare different sizes and their effects.
What is aspect ratio in tire sizing?
Aspect ratio is the tire's sidewall height as a percentage of its width. For example, in a 265/70R17 tire, 70 means the sidewall height is 70% of the 265mm width. A lower aspect ratio means a shorter sidewall.
How does tire size affect performance?
Tire size impacts various aspects of performance including handling, acceleration, braking distance, and fuel economy. Larger tires may improve stability but can reduce acceleration, while smaller tires might improve fuel efficiency but could affect ride comfort.
What happens if I install the wrong tire size?
Installing incorrect tire sizes can lead to several issues: inaccurate speedometer readings, altered vehicle handling, reduced fuel efficiency, potential rubbing against vehicle components, and possible damage to your vehicle's drivetrain. It may also affect your vehicle's ABS and traction control systems.
How do I calculate tire circumference?
Tire circumference can be calculated by multiplying the total diameter (wheel diameter + twice the sidewall height) by π (3.14159). Our calculator automatically performs this calculation for you, giving you accurate results for any tire size.
What's the difference between P-metric and LT tires?
P-metric tires are designed for passenger vehicles, while LT (Light Truck) tires are built for heavier vehicles and loads. LT tires typically have stronger sidewalls and higher load ratings. The sizing format is similar, but load capacities and recommended pressures differ.
How do plus-size tire upgrades work?
Plus-sizing involves increasing wheel diameter while decreasing sidewall height to maintain a similar overall tire diameter. For example, going from 215/65R16 to 215/55R17. This can improve handling but may affect ride comfort and cost more.
Why do my tire sizes have different measurements in inches and millimeters?
Tire sizing uses a mix of metric and imperial measurements due to historical industry standards. Width is in millimeters (e.g., 265mm), while wheel diameter is in inches (e.g., 17 inches). Our calculator helps convert between these measurements for easier comparison.
How often should I check my tire size?
You should verify your tire size when: replacing tires, buying new wheels, experiencing unusual handling, noticing uneven wear, or considering performance modifications. Always ensure replacements match your vehicle's specifications or are properly calculated alternatives.
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