The section width is the width of the tire from one sidewall to the other measured in millimeters. In this example, the tire is 245 millimeters wide. 45 =Aspect Ratio (Ratio of Sidewall height to width) The aspect ratio refers to the height of the sidewall, and it is a percentage of the section width. What Do The Numbers On Tires Mean? Tire service type ratings. Most tire sizes begin with one or more letters -- for example, P or LT. The letter tells us P = P-Metric (Example: P215/65R17 98T). P-Metric tires are the most common type of tire. The P stands for passenger Metric / Euro-Metric Diameter : 35 The Diameter of this tire size is 35 inches. The first number in a high flotation tire size is the overall diameter of the tire. Section Width : 12.50 The width of this tire size is 12.5 inches. The second number in a high flotation tire size is the width of the tire in inches. Tire Construction : R Tyre size explained Tyre dimensions. Width: The section width of your tyre in millimetres, from the inner sidewall to the outer sidewall. Example: 195mm. Aspect Ratio: The height of your tyre from the base of the tread to the rim, as a percentage of the tread width. Low profile tyres have smaller aspect ratios. The number 185 is the tire's width in millimeters, from one sidewall to the other. The number 60 after the forward slash character means the tire's height from rim to tread is 60 percent of its width, which again is 185 millimeters. R14 means the tire is meant to fit on a 14-in. diameter wheel. Finding your tire size is not difficult, you just need to know where to look! In today's article I'll explain tire sizes, how to find yours, what the numbers on a tire mean, and how to shop for and buy tires that will fit your car or truck. Let's start with the basics. Tire Size Meanings A: TIRE TYPE. The first letter in the code tells you what class of tire it is. P stands for passenger vehicle tire. B: TIRE WIDTH. The three-digit number following the letter is the tire's width (from side to side, looking at the tire C: ASPECT RATIO. The forward slash Tire Width The tire width is measured from sidewall to sidewall of the tire. It is represented by a three digit number and measured in millimeters. In our example above, the width is 185mm. Aspect Ratio Aspect ratio is the ratio of the height of the tire's cross-section to its width. The most basic information that you'll find on a tire's sidewall is related to its size. This is normally written as 185/65R15, for example, though you'll sometimes see "P" (for passenger cars) A "C" indicates 6 plies, a "D" indicates 8 plies, and an "E" indicates 10 plies. The higher the number of plies in a tire, the stronger the tire is and the more air pressure the tire can safely hold. Higher ply tires require more air pressure to maintain proper wear. n3Irzze.