How to calculate tire equivalences and measurements

When we want to change the tires of our vehicle, either because they are worn or because the wheel has been punctured, we have to take into account a series of aspects, since we do not have any type of tire. What we must have is present is nothing other than the equivalences and measures of the tires.

Do not know how to calculate it or how to know which one your vehicle needs? Do not worry, because in this article we explain everything you need to know about how to calculate the equivalences and measurements of the tires to get the most suitable for your means of transport.

What are the equivalences of the tires

The equivalences of the tires help us to know if the tire we want to acquire is suitable for our vehicle in terms of measurements, both for the good functionality of the car and not having any problems after passing the ITV.

According to the Order 3191/2002 of the BOE (Official State Gazette), it is not necessary to approve the new tires if they meet a series of characteristics:

  • Diameter of the exterior : this must have approximately the same size. However, a small variation of 3% is accepted.
  • Load capacity : this must be equal or higher.
  • Speed ​​category code : must be equal or higher. Only in the case of M + S tires is a somewhat lower level permitted.
  • Assembly rim : the profile of the mounting rim must correspond to that of our tires.

How to know the tire size

Knowing the measurements of your original tires is easier than you think. All the information you need is on the side of the wheel, there you will find:

  • The width of the wheel.
  • The profile of the tire.
  • The load capacity of the wheel.
  • The speed of the tire.

How to read the tire size

Whatever your tire, the pattern will always be the same: XXX / XX A XX XXA . In this case, the X represents a number, and the A represents a letter. Suppose that the measurements of our tire are 220/40 R 10 92V:

  • 220 : this indicates the width of the tire. The measurement is in millimeters.
  • 40 : this figure is the profile of the tire, that is, its height. In this case it is a percentage, that is, the height of the tire is 44%.
  • A : in this case, it means that the tire has been built radially.
  • 10 : this indicates the measurement of our tire. Here it is indicated in inches.
  • 92V : this is a code that equals the load capacity and the maximum speed it can withstand.

Tire equivalence calculator

The easiest way to calculate the equivalences and measurements of the original tires with the new ones that we want to look for, is to go to an on-line tire equivalence calculator, like the one we offer here.

In the tire equivalence calculators, you only have to enter the measurements of your original tires and the measurements of the tires you want to purchase. The calculator will automatically tell you if those new wheels are suitable or not for your vehicle. Therefore, it is ideal to do this step before buying the new tires.

How to know what tires I can put on my car

Now that you know how to calculate tire equivalences and measurements, you may be wondering what kind of tires are right for your vehicle. In we give you the answer in these two articles:

  • How to choose the tires for an SUV.
  • How to choose car tires.