Tire Diameter Calculator

Use metric tire dimensions to calculate theoretical overall diameter in inches and millimeters.

Section width (mm)

Aspect ratio (%)

Wheel diameter (in)

—Diameter

—Diameter metric

—Sidewall

—Circumference

—Formula: wheel diameter + two sidewalls. Published tire dimensions can differ slightly.

How to use this Tire Diameter Calculator

Calculate overall tire diameter from width, aspect ratio, and wheel diameter. Enter your values above and the result is calculated directly in your browser. No account is required.

Fast answer, clear inputs

This tool is built around one job: give the answer quickly without forcing a signup or hiding the result. Related tools are linked nearby when the next calculation or conversion is useful.