What Tyres Fit My Rims? Simple Size Guide

Photo of Author Verified
Researched, written and verified
Verified
Our methodology focuses on accuracy first.
Research is carried out using primary manufacturer data, official guidance, and trusted industry sources. Where appropriate, content is cross-checked against real-world fitting practices and common customer queries to ensure it is practical as well as technically correct. Articles are reviewed periodically and revised when regulations, standards, or best practices change.
 by Chesca D
Photo of Author
Chesca D is a Content & Editorial Coordinator at Tyres.co.uk and is responsible for researching, coordinating, and producing accurate, up-to-date tyre guidance for our Knowledge Hub..
Each article is created using manufacturer specifications, recognised industry standards, and current UK regulations, and is reviewed internally to ensure clarity and technical accuracy. Content is updated regularly to reflect changes in tyre laws, safety guidance, and product specifications.
Fact-checked by the Tyres.co.uk editorial team
Article Image

Not sure which tyres will fit your car’s wheel rims? This quick guide explains how to read tyre sidewall markings, measure your rim diameter, and match your tyres for a perfect fit. Discover how to balance performance, safety, and comfort when choosing your next set of tyres with expert advice from Tyres.co.uk.

Choosing the right tyres for your vehicle is not simply a matter of price and preference. It is also about getting the perfect size and fit for your wheel rims – ensuring that the tyres sit snugly, balancing the weight of the car and adapting to the road surfaces you drive on.

This is where your tyre size calculation comes in, using the letters and numbers that are printed on the tyre sidewall.

Understanding the Tyre Sidewall Markings

When you look at the sidewall of a tyre, you will notice a series of markings. These numbers, letters, and symbols all refer to different components of the tyre and are used by drivers to establish the size of the tyre and its ratings.

To find a tyre that fits your wheel rims, you need to look at a specific portion of this string of letters and numbers. Let’s take a closer look at how to interpret the tyre size and wheel rim diameter.

Finding the Right Size Using an Example Tyre Reference

The marking that you are looking for on your tyre sidewall will look something like this:

225/45 ZR17 94Y

In this example, the component of the marking that connects tyre size with the wheel rim measurement is the number ‘17’.

This essentially means that the tyre in the example will fit on a wheel rim that measures 17cm in diameter.

How To Know Your Wheel Rim Measurement

Most drivers will purchase a car with tyres already fitted, and so they can simply identify the wheel rim diameter using the markings on the previous tyres’ sidewall. This tends to be the easiest and most foolproof way of ensuring that you buy tyres that fit the wheel rims perfectly. 

However, if you are starting from scratch and need to measure your wheel rim diameter, you can do so with ease – measuring from one side to the other in centimetres.

Article Image

Tips for Choosing the Right Tyres

Beyond measuring the wheel rim diameter and ensuring that your tyres are a perfect fit over the wheel rim, other things to consider include the load and speed ratings, and of course the season that you are driving in.

Some drivers in the UK choose to change their tyres from winter to summer tyres with the change in season, leaning into the optimised performance of good traction in the winter and a sturdier compound in the summer. Others opt for the convenience and ease of all-season tyres, which work sufficiently in the relatively temperate UK climate. 

Whatever your preference, choosing the best tyres starts with getting the right fit. At Tyres.co.uk, our team can help you to break down the tyre size calculation and identify the important points, so you can browse and buy with confidence.

Back to Knowledge Hub