Tyre Size Calculator & Comparison
Compare two tyre sizes such as 195/65R15 and 205/55R16, including sidewall height, overall diameter, circumference and approximate speedometer difference.
Sidewall112.8 mm
Overall diameter631.9 mm
Circumference1,985.2 mm
Diameter difference-0.41%
At indicated 100 km/h, actual speed: 99.6 km/h
A diameter difference within roughly ±3% is commonly used as a comparison rule of thumb, but fitment still must be verified.
How it works
Enter width, aspect ratio and wheel diameter for the original and replacement tyre. The tool calculates geometric differences.
Important
A mathematically close tyre size may still be unsuitable because of load rating, speed rating, rim width, suspension or body clearance. Confirm fitment with the vehicle or tyre manufacturer.