Tire Size Calculator
Calculate the overall diameter of a tire from its size.
Result
Results are estimates for general information only and are not professional advice.
Reading tire sizes
A tire code like 205/55R16 means a 205 mm width, a sidewall that is 55% of the width, on a 16-inch rim. This calculator combines those to give the overall tire diameter in millimeters and inches, plus its circumference.
Frequently Asked Questions
What is the Tire Size Calculator?
Calculate the overall diameter of a tire from its size. It runs instantly in your browser and is completely free.
Is the Tire Size Calculator free and does it require signup?
Yes. Every calculator on Calculatis is 100% free with no registration, and the values you enter are never stored.
How accurate is the Tire Size Calculator?
It uses standard, widely-accepted formulas. Results are reliable estimates for general use and are not a substitute for professional advice.