How to read your Tyre size

Need a new tyre? Can you tell us your tyre size? There is always a series of numbers and letters on the side of a tyre. Each of these numbers and letters represent part of the tyre’s size and more key information about the tyre. To understand this information, LTC Tyres and Exhausts Halesowen have put together a handy guide to help you get to know your tyres and to help you understand and read the correct tyre size that you require! 

Tyre size

On the sidewall of your tyre, you will find a combination of numbers and letters. Commonly, tyres will read 205/55R16. However, there are multiple versions, so check your current tyres.

You can also find your vehicle's tyre size via the vehicle handbook. It's always important to know the correct tyre size specific to your vehicle, this will ensure you're running on the correct wheels which will save you time and money.  

Tyre Width (A)

The width of your tyre, in millimetres, measured from sidewall to sidewall. If your tyre is marked as 205, this is reading that your tyre is 205 millimetres across the tread, measuring from one side of the sidewall to the other. 

Aspect Ratio (B)

The profile height or aspect ratio of the sidewall of the tyre is referenced as a percentage of the tyre width. This is the ratio of the tyre’s cross-section to its width, expressed as a percentage. An aspect ratio of 55, for example, indicates that the tyre’s height is 55% of its width.

Wheel Diameter (C)

The Height diameter of the alloy wheel is measured in inches. This is important to allow the tyre to fit correctly.

Load Index (D)

Your tyre’s load index relates to its maximum carrying capacity in kg. You’ll find the load rating of your tyre on the sidewall, just to the right of the diameter.

For example, a tyre with a load index of 91 can carry 615kg of weight. Here is a table below that LTC Tyres and Exhausts have provided to better understand Load Ratings.

Speed Rating (E)

The speed rating is the maximum speed for a tyre when it is correctly inflated and being used under load. The Speed Rating is the letter located after the Load Index (D). Please see the image below that LTC Tyres and Exhausts Halesowen have put together for you.

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LTC Tyres & Exhausts Halesowen
Centre Court, Vine Ln, Halesowen B63 3EB
Tel: 0121 550 6084

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LTC Tyres and Exhausts services: Tyre fitting, Alloy Wheels, Exhausts, Mobile Fitting, Brakes, Batteries, Puncture Repairs, Vehicle Servicing, Wheel Repairs, Wheel Alignment, Air-Con Recharges, TPMS, Locking Wheel Nut Removal and much more.