Before you start looking for 33″ tires for sale, you have to get a basic understanding of tire sizes first. In this article, we will discuss how to interpret tire sizes as well as how to use a tire calculator.
Tire Sizes
In order to understand tire sizes, the first thing you have to know is that there are two basic tire size measurement systems available. These are: Metric and Standard Inch.
A metric tire size usually reads this way: 275/40R17
In this specific measurement, ’275′ stands for the section width or the tire width, which is basically how wide the tire is from the outer sidewall to the inner sidewall in terms of millimetres.
’40′ or the number after the slash is referred to as the sidewall aspect ratio or the tire’s profile. This is basically the height of the sidewall divided by the tire width. Therefore, the taller the sidewall is, the higher the aspect ratio is also and vice versa.
In reverse, if you want to get the height of the sidewall, simply convert the section width from millimetres to inches and then multiply by the aspect ratio. In this case, if you convert 275 mm to inches, it would be 10.8 inches and then multiplying that by 40% would result in a sidewall height of 4.32 inches.
R stands for the radial construction, and can sometimes be replaced with a D for diagonal construction or a B for belted construction, though this is not common.
Finally, 17 stands for the rim size or the diameter of the tire and the wheel.
Sometimes, the metric tire size will read P275/40R17 or LT275/40R 17. In this case, P indicates that the vehicles is a passenger car while LT stands for light truck.
Now, let’s take a look at the standard inch system.
A standard inch tire size usually reads this way: 33×10.50R17
Here, the first number is the overall diameter of the tire measured in inches – 33 inches. Therefore, if you are looking for 33-inch tires, then are looking for tires that have a diameter of 33 inches and as such, the size should begin with 33.
The second number is the width of the tire tread also in inches – 10.50 inches – and finally, the last number is the rim size or rim diameter.
Using A Tire Size Calculator
Most tire sizes are metric so before you find 33″ tires, you may need to convert the standard inch tire size to metric. To do this, you will need to use a tire size calculator.
If you can’t find one, though, you can do the conversion manually. Here’s how:
1. Convert the tire width from inches to millimetres, rounding it off. This will give you the first component of the metric system.
2. Calculate the sidewall height by subtracting the rim diameter from the overall diameter (the last number from the first number) and divide it into half.
3. Finally, divide the new number, the sidewall height, by the original tire width in inches.