Tire Size Calculator

Calculate tire sidewall height, overall diameter, and circumference from width, aspect ratio, and rim size.

Preparing Tire Size Calculator

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Input

Enter tire width, aspect ratio, and rim diameter to calculate the tire's core dimensions. This tool shows the result instantly without step-by-step output.

Input summary

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How to use Tire Size Calculator

Provide the tire-size numbers from the sidewall format, and the calculator will translate them into physical dimensions you can compare.

What this calculator is for

This calculator is for wheel-and-tire comparisons, gearing discussions, and garage planning when a sidewall code needs to become a measurable diameter or circumference.

Tips

A tire-size change can affect speedometer reading and clearance, so compare the diameter difference before switching sizes.
The result is a theoretical dimension and actual mounted tire measurements can vary by tire model and wheel width.