Tire Aspect Ratio Calculator — Calculate Tire Dimensions & Sizes

Tire Aspect Ratio Calculator

Calculate tire aspect ratio, overall diameter, revolutions per mile, and sidewall height with our comprehensive calculator. Determine correct tire sizing and compatibility for your vehicle.

Step 1: Tire Specifications

55%
17″

Understanding Tire Aspect Ratio

The aspect ratio is the height of the tire’s sidewall expressed as a percentage of the tire’s width. For example, a 225/55R17 tire has an aspect ratio of 55%, meaning the sidewall height is 55% of 225mm.

Step 2: Calculation Parameters

95

About Tire Calculations

Tire calculations help ensure proper fitment, maintain accurate speedometer readings, and optimize vehicle performance. Always verify tire compatibility with your vehicle’s specifications.

Tire Calculation Results

Summary
Size Comparison
Breakdown

Overall Tire Diameter

26.7″
225/55R17 tire dimensions
Sidewall Height
123.8 mm
Revolutions per Mile
777.5
Tire Width
225 mm
Aspect Ratio
55%

Tire Size Comparison Table

Tire Size Overall Diameter Sidewall Height Revs per Mile

Tire Dimension Breakdown

Tire Calculation Formulas

Overall Diameter = (Tire Width × Aspect Ratio × 2 / 1000) + (Wheel Diameter × 25.4)

To calculate tire diameter: Multiply tire width by aspect ratio (as decimal), multiply by 2, divide by 1000 to get meters, then convert wheel diameter from inches to mm and add together, finally convert back to inches.

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