Why use a Tire Size Calculator?

Using a Tire Size Calculator is essential when upgrading your car's wheels. Changing your tire size can affect your vehicle's speedometer accuracy, clearance, and overall safety. Our tool helps you compare the original tire diameter with the new one to ensure a perfect fit.

Understanding Tire Specifications

• Width (mm): The width of the tire from sidewall to sidewall. Wider tires generally offer better grip but may increase fuel consumption.
• Aspect Ratio (%): The height of the tire's sidewall as a percentage of its width. Lower numbers mean a thinner profile (sporty look).
• Rim Diameter (in): The size of the wheel (rim) that the tire fits onto.

The 3% Rule for Tire Replacement

When changing tire sizes, industry experts recommend keeping the total rolling diameter within 3% of the original size. Exceeding this limit can cause brake failure warnings, transmission issues, and significant speedometer errors.

How to Check Speedometer Error?

If you install larger tires, your speedometer will read slower than your actual speed. For example, if our calculator shows a 5% difference, driving at a speedometer reading of 100 km/h might mean you are actually traveling at 105 km/h. Use this tool to stay informed and avoid speeding tickets.