How to check your tyre size
31st March 2023
It’s essential to know your tyre size for proper maintenance and the inevitability of purchasing a new set in the future. This knowledge can help you to find the best tyre options available for your vehicle.
How to find your tyre size:
There are a few ways you can go about this. Firstly, look at your current tyres. Looking at the sidewall of the tyre, you will see a line of numbers in large text. These are the sizing metrics which will look like this example – 255/55R16. The tyre size is broken down by section, profile and rim which we explain more about below.
For a more detailed breakdown of the available tyre sizes for your vehicle and the required pressures, you can look for the sticker usually found in the door jamb, or in your vehicle’s owners manual.
So what does this sizing mean, and how do I read my tyre size?
This may seem confusing at first but once broken down you can gain a better understanding of what these numbers mean.
Using the example of a tyre labelled 255/55R19 111V we can break it down as follows:
- A: Section – 255 represents the width of a tyre in millimetres. In this example, the tyre is 255mm wide.
- B: Profile – 55 is the aspect ratio, which represents the height of the tyre as a percentage of the width. So here, the aspect ratio of 55 means the profile height is 55% of the tyre’s total width.
- C: Rim – R19 is the diameter of the tyre’s inner rim in inches. The R stands for Radial.
Load and speed are almost always combined into one section:
- D: Load – 111 is the load capacity of the tyre. The number shown on the tyre represents weight in KG – in this case 111 represents 1,090kg. Some larger vehicles with a twin wheelbase may go further than a single number e.g. 120/121R – the first number being single-mounted and the second being dual-mounted. The AA website has a helpful explanation of every single load rating which you can find here.
- E: Speed – V is the maximum speed for this tyre at full load. Tyre speed ratings are represented by a letter, each representing a different top speed. V means the tyre can travel up to a maximum 149mph.
The below table shows each of the speed ratings:
| Speed Rating | MPH |
| Q | 99 |
| R | 106 |
| S | 112 |
| T | 118 |
| U | 124 |
| H | 130 |
| V | 149 |
| W | 168 |
| Y | 186 |
While tyre speed ratings are important to consider when choosing the right tyres for your vehicle, they are not the only factor to take into account. Other factors such as tread pattern, and seasonal tyres can also affect your vehicle’s performance and safety on the road.
Tips when you’re checking your tyre size:
- Often your tyres will differ on the front and rear sizes so don’t assume they are all the same.
- If you wish to increase or decrease in size, consult your local Landsail dealer, who will be happy to help you.
Still unsure? Always contact an expert. You can reach out to your local Landsail distributor for more information or contact us directly with your question here.
You can also check out Landsail Tyre Teacher Fuzz Townshend’s video on how to read a tyre here.
To learn more about Landsail tyres and our range check out our product page here.
