#TYRE ASPECT RATIO CALCULATOR MANUAL#

If a tyre has an aspect ratio of 70, it means the tyre’s height is 70% of its width. Tyre makers calculate the aspect ratio by dividing a tyre’s height off the rim by its width. Aspect ratios are delivered in percentages. Aspect RatioĪfter the slash mark, the next number you see is for the tyre’s aspect ratio, which essentially tells you how tall your tyre’s profile is: 225/ 70/R16 91S. Thus, a tyre with the measurement “P225” is for a passenger vehicle and has a nominal width of 225 millimetres. Tyre width always refers to the measurement from one sidewall to another. The first number to appear in your tyre size information is the width, in millimeters, of the correct tyres for your vehicle: 225/70/R16 91S. If you see “ST,” that means “special trailer.” Width Similarly, “T” stands for “temporary” and is for your spare tyre. Light truck tyres are designed to be used on vehicles capable of carrying heavy cargo or pulling trailers. If you see “LT” instead of “P,” it’s because you need “light truck” tyres – “LT” is short for “LT-metric” which is a designation by the Tyre and Rim Association for a “light truck” type tyre. This signifies the tyre was designed to primarily be used on passenger vehicles, which can include cars, minivans, SUV’s, and other light duty pickup trucks. The “P” is short for “P-metric” which is a designation by the Tyre and Rim Association for a “passenger car” tyre type. We'll be using this tyre size as an example: 225/70/R16 91S.įor most vehicles, you’ll see the letter “P” before the number sequence begins: P225/70R16 91S. Let’s take a look at what each number or letter stands for, one by one, in the order they appear in your tyre size data. However, no matter where you find your tyre size, you will have to decipher a sequence of numbers and letters.

#TYRE ASPECT RATIO CALCULATOR MANUAL#

The best place to start looking is the owner’s manual.ĭon’t worry if you can’t locate the manual you may also find a tyre fit guide in these locations:Īssuming your current tyres are the originally fitted, you can find tyre size data on the sidewall of your tyres. No matter what vehicle you drive, finding the manufacturer-recommended tyre size should be easy.

Things like load index and speed rating are also integral to finding the correct tyres. While actual, physical measurements like width and diameter are factors in finding the right tyre size, there are additional details you should consider. If you already know your tyre size and would like to find the right Bridgestone tyre for your vehicle, visit our Tyre Catalog. All the information you need is immediately available either in the owner’s manual for your vehicle or somewhere within the vehicle itself. Thankfully, determining the correct tyre size for your vehicle is fairly simple.

You should understand what tyre size is right for your vehicle to be able to make the right choice when it's time to buy tyres. Your tyre choice should reflect the conditions in which you drive and your preferences for vehicle response and handling. Installing the right tyres on your vehicle is important to the overall performance and safety of your vehicle.

Tyre aspect ratio calculator