How to Read a Tyre Size (So You Can Book the Right One in Seconds)
Those numbers on your tyre's sidewall look like a code — but they're easy to read once you know the pattern. Here's exactly what each part means, so you can fill in our quote form correctly first time.
If you've ever looked at your tyre's sidewall and seen something like 205/55R16 91V and had no idea what it meant, you're not alone. The good news is that it follows a simple, standard pattern once you know what to look for — and getting it right means we can quote you accurately over the phone or through our online form without needing to see the car first.
Where to find your tyre size
The size is moulded directly into the rubber on the outer sidewall of the tyre — the side facing out when the wheel is on the car. It's usually raised lettering rather than printed, so run a finger over it if it's hard to read in poor light. Check the actual tyre fitted to the car rather than the door sticker or handbook: some vehicles are supplied with different sizes for the front and rear axles, and a previous owner may have fitted a different size to the original spec.
Breaking down the code: 205/55 R16 91V
Let's take a common example and go through it piece by piece.
The width of the tyre in millimetres, measured sidewall to sidewall. This tyre is 205mm wide.
The sidewall height as a percentage of the width. Here, the sidewall is 55% of 205mm — about 113mm tall.
Radial construction — the standard on virtually every modern car, van and 4x4 tyre.
The diameter of the wheel the tyre is designed to fit, measured in inches. This tyre fits a 16" rim.
A code representing the maximum weight the tyre can carry when correctly inflated — 91 corresponds to 615kg per tyre.
The maximum speed the tyre is rated for — V means up to 240 km/h. Common ratings include S, T, H, V and W.
Why getting the size right matters
- A tyre that is the wrong width or profile may not fit your wheel or could rub against the arch or suspension.
- Fitting a lower load index or speed rating than the vehicle manufacturer specifies can be unsafe and may affect insurance.
- Changing tyre size can affect your speedometer accuracy and may require the TPMS system to be re-checked.
- Giving us the exact size when you book means we can have the right tyre ready before you arrive — no waiting around.
What if I still can’t read it?
Dirt, brake dust and kerb scrapes can make the sidewall hard to read, especially on older tyres. If you're really stuck, take a clear photo of the sidewall and attach it when you message us, or just call the workshop — we're happy to talk you through it or take a look when the car comes in.
Ready to book your tyres?
Pop the size you’ve just found into our quote form or booking calendar and we’ll get you a straight price.
Sorted on the size — now book it in.
Send us the size through our quote form or grab a slot on the booking calendar.