Tyre size 225/45 R18
Find 225/45 R18 Tyres
Free guidance for 225/45 R18 tyres. Premium saloons and family cars. Always confirm fitment on your tyre sidewall.
Tyre Size Checker
Enter a UK tyre size such as 205/55 R16 91V to decode the width, profile, rim, load index and speed rating.
Find your tyre size on the sidewall, the driver's door frame, fuel flap or vehicle handbook.
- This tyre size may be incomplete. A full tyre size often looks like 205/55 R16 91V. Check your tyre sidewall for the load index and speed rating.
What 225/45 R18 means
225 is the section width in millimetres. 45 is the profile (sidewall height as a percentage of the width). R is radial construction. 18 is the wheel rim diameter in inches.
A full tyre size also includes a load index and speed rating, e.g. 225/45 R18 91V. The load index maps to a maximum weight per tyre, and the speed rating maps to a maximum speed at full load.
Where 225/45 R18 is commonly fitted
Premium saloons and family cars.
Even when a tyre size is common, the specific tyre that's right for your vehicle depends on the load index, speed rating, and sometimes whether the original equipment is run-flat or EV-rated. Always confirm with your tyre sidewall, vehicle handbook or a qualified UK tyre fitter before fitting.
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You can find this on your tyre sidewall.
This tyre size may be incomplete. A full tyre size often looks like 205/55 R16 91V. Check your tyre sidewall for the load index and speed rating.
Step 1 of 7 — Start
What to check before fitting
- Confirm the size on your tyre sidewall
- Match or exceed the original load index and speed rating
- Check the EU tyre label for wet grip, fuel and noise
- Pick the right type — summer, all-season or winter
- Fit as a full set or at least a matched pair on the same axle
Frequently asked questions
Quick answers about UK tyre fitment, MOT rules and seasonal options.
What speed rating should I look for on 225/45 R18?
Speed rating is a single letter at the end of the size — H (210 km/h), V (240 km/h), W (270 km/h), Y (300 km/h). Use the original specification for your car as the minimum.
Can 225/45 R18 tyres be repaired after a puncture?
Standard 225/45 R18 tyres can usually be repaired if the puncture is in the central tread area, smaller than 6mm and not on the sidewall. Run-flat versions of the same size often cannot be repaired.
Can I read 225/45 R18 backwards from a wheel listing?
If you only know the wheel — for example a 18-inch alloy with width X — the tyre size is usually engraved or labelled separately. Don't assume from rim diameter alone; many cars run different widths and profiles on the same rim size.
What load index do I need with 225/45 R18?
Load index is on the placard inside your driver's door frame. 225/45 R18 can be ordered in different load indices (e.g. 91, 94, XL/RF) — match or exceed the original specification for your car.
What does 225/45 R18 mean?
225/45 R18 reads as: 225mm tread width, sidewall height 45% of width (≈ 101mm sidewall), and a 18-inch rim diameter. A complete size includes a load index and speed rating, e.g. 225/45 R18 91V.
Tyre sizes related to 225/45 R18
Same rim, similar width or profile — common alternatives UK drivers compare with 225/45 R18.
Tyre Finder UK provides general tyre guidance only. We do not guarantee tyre fitment, local stock, prices or fitting availability. Always confirm your tyre size, load rating, speed rating and vehicle requirements using your current tyre sidewall, vehicle handbook, manufacturer guidance or a qualified tyre fitter before fitting.