Tire Size Calculator

Reading Tire Sizes

A standard tire code looks like: 225/45R17

1. Width (225): The width of the tire in millimeters.
2. Aspect Ratio (45): The height of the sidewall as a percentage of the width.
   • Sidewall Height = $225 \times 0.45 = 101.25$ mm.
3. Rim Diameter (17): The diameter of the wheel in inches.

Calculations

• Total Diameter: Rim Diameter + (2 × Sidewall Height).
• Circumference: $\pi \times \text{Total Diameter}$.
• Revs Per Mile: How many times the tire rotates in one mile (63,360 inches).