Tire Size Calculator

Enter your tire size to calculate overall diameter, sidewall height, circumference, and revolutions per mile or km.

Tire Size

mm
%
in
Results
Overall Diameter
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Sidewall Height
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Circumference
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Revolutions per Mile
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Tire Side View

How it works

The tire size code (e.g. 205/55R16) encodes three measurements: section width in mm, aspect ratio as a percentage of the width, and rim diameter in inches. The overall diameter is calculated as:

diameter = (width × profile% × 2) + (rim × 25.4)