What is the Tyre Size Calculator?
A tyre size like 185/65 R15 means: 185 mm wide, sidewall height 65% of the width, fitting a 15-inch rim. Enter your current size and a new size to compare overall diameter, sidewall, circumference and revolutions per km – and how much your speedometer will be off. Keep the difference within ±3%.
How to use the Tyre Size Calculator
- Enter the current tyre size.
- Enter the new tyre size you are considering.
- Check the diameter difference and speedometer error.
Rule of thumb
Stay within ±3% overall diameter to avoid ABS, speedometer and clearance problems.
This Tyre Size Calculator is 100% free, needs no signup and runs privately in your browser – on phone, tablet or computer.
Last updated: · By NodifyTech