BackHow to Read Tire Size: The Ultimate Guide for Beginners
Confused by the numbers on your tire sidewall? Our guide breaks down tire size, speed rating, and load index so you know exactly what to buy.
The short answer
A tire size like 195/75R14 encodes three physical dimensions: the tire is 195mm wide, the sidewall height is 75% of that width, and it fits a 14-inch wheel. The "R" means radial construction — the standard for all modern passenger tires. Once you know the pattern, any sidewall number becomes readable in seconds.
The Tire Size String Explained
Let's use 195/75R14 as an example. This sequence tells you everything about the physical dimensions of the tire.
1. Tire Width (195)
The first number is the width of the tire in millimeters from sidewall to sidewall. A 195 means the tire is 195mm wide.
2. Aspect Ratio (75)
The number after the slash is the aspect ratio, which represents the height of the tire's sidewall as a percentage of its width. In this case, the sidewall height is 75% of 195mm.
3. Construction Type (R)
The letter "R" stands for Radial, which is the standard construction method for modern passenger vehicle tires.
4. Wheel Diameter (14)
The final number indicates the diameter of the wheel (in inches) that the tire is designed to fit. This tire requires a 14-inch wheel.
Finding the Right Fit
Always check your vehicle's owner's manual or the sticker on the driver's side door jamb for the recommended tire size.
If you are looking for a reliable everyday tire, the HANKOOK KINERGY ST H735 offers excellent all-season performance and durability.
FAQ
Do I really need to stick to the exact size?
A: Yes. Changing the tire size without adjusting the wheel or suspension can cause clearance issues and affect your speedometer accuracy.
What if I want wider tires?
A: You can sometimes install wider tires, but you must lower the aspect ratio to maintain the same overall wheel diameter. This is called "plus sizing."
Bottom line
Understanding tire size is the first step to ensuring your vehicle's safety and performance. Always verify the required size for your specific make and model before making a purchase.
