Tyre Sizes Guide
Understanding your tyre size can be confusing. Until you’re actually faced with having to replace a tyre, the codes on the sidewall of your tyre may seem like a random collection of numbers, but they actually contain vital information about the tyre size your car needs. Each tyre code is used to identify the size, manufacturer and physical features of the tyre and is displayed in this format 205/55R16. In this guide, we’re going to look at the numbers you should pay attention to on your tyre and what each one relates to when you need to buy new tyres.
How to read tyre codes
Your tyre code is a sequence of numbers and letters. With so many different tyre codes available, it’s important to know your existing tyre size to ensure you know what size to order when replacing. The most common UK tyre size is 205/55R16, let’s break down what each part of this code means.
Tyre Width
In this code, the 205 relates to the width of the tyre with the three digits displaying the width in millimetres. A tyre marked with 205 at the start will measure 205mm across the tyre tread from sidewall to sidewall.
Aspect Ratio
The next two digits on your tyre code are the aspect ratio, or profile height of the tyre sidewall expressed as a percentage of the tyre width. Using the 205/55R16 code, the 55 shows that the aspect ratio of the tyre is 55% of the width.
Radial
Almost all new tyres manufactured in the UK are radial tyres. This means that they are constructed with cord piles positioned at a 90-degree angle to the direction of travel in order to give the tyre extra strength. The letter R in the tyre code will identify that your tyre is a radial tyre.
Wheel Diameter
The next two digits on your tyre code identify the size of the wheel rim that the tyre is fitted to, it’s also the diameter of the tyre from bead to bead. In this code 205/55R16, the 16 identifies that the tyre will fit on a 16-inch wheel rim.
What do the other tyre numbers mean?
Although you typically only need the initial code to identify your tyre size, there are other markings on the tyre that you can familiarise yourself with.
Tyre load index
The load index represents the maximum load that the tyre can carry when it is inflated to it’s maximum (safe) pressure. For example, if your tyre has the number 97 following the main tyre code, this identifies that it relates to index 97 on a ‘look-up’ table, which is used to determine the load in kg.
What is the speed rating on tyres?
The speed rating is displayed in the form of a letter and represents the maximum speed that a tyre can carry a load safely. Speed ratings range from A (the lowest) to Y, with H as the exception as it is rated between U and V. As with the load index, each speed rating letter corresponds to a value in km/h. It’s important to note that the maximum speed that your tyre CAN carry does not mean that you can ignore legal speed requirements!
Need help finding the right tyre size? At Tyre Savings, you can search by the size of your tyre or by your vehicle registration. If you have any further questions, get in touch with a member of our team today.
- 195 65 15
- 195 55 16
- 205 55 16
- 185 65 15
- 195 60 15
- 175 65 14
- 185 60 15
- 175 65 15
- 185 55 15
- 205 65 15
- 195 60 16
- 165 70 14
- 195 55 15
- 205 60 15
- 195 45 16
- 195 50 15
- 175 70 14
- 195 50 16
- 165 65 15
- 185 65 14
- 185 60 14
- 205 45 16
- 165 65 14
- 205 50 16
- 185 70 14
- 165 60 14
- 185 55 16
- 155 65 14
- 185 50 16
- 175 55 15
- 165 60 15
- 165 70 13
- 155 65 13
- 155 70 13
- 165 65 13
- 155 80 13
- 175 60 15
- 185 55 14
- 215 65 15
- 195 70 14
- 155 60 15
- 185 60 16
- 175 70 13
- 175 80 14
- 145 65 15
- 205 70 15
- 205 50 15
- 225 60 15
- 195 45 15
- 165 80 13
- 175 60 16
- 195 65 14
- 175 60 13
- 195 60 14
- 145 80 13
- 175 50 15
- 175 65 13
- 205 55 15
- 165 50 15
- 185 70 13
- 145 70 12
- 175 60 14
- 205 70 14
- 205 60 14
- 155 70 12
- 185 50 14
- 185 45 15
- 195 65 16
- 165 60 13
- 215 60 15
- 165 55 15
- 175 70 12
- 165 70 12
- 165 45 15
- 135 70 15
- 175 50 16
- 185 60 13
- 155 70 14
- 145 70 13
- 165 45 16
- 205 60 13
- 165 40 16
- 145 80 12
- 165 80 15
- 215 70 15
- 165 60 12
- 165 50 16
- 155 80 12
- 165 55 13
- 225 70 15
- 185 80 14
- 195 75 16
- 175 50 14
- 195 80 15
- 135 80 15
- 225 50 15
- 31 10 15
- 165 80 14
- 195 40 16
- 155 80 14
- 235 60 15
- 175 50 13
- 195 45 14
- 175 80 13
- 145 80 15
- 165 55 14
- 205 40 16