Use the search tool with your UK registration for the recommended fitment, or check the tyre sidewall for a size like 205/55 R16 plus the load index and speed rating.
It is best to stick to manufacturer-approved sizes; changing size can affect handling, speedometer accuracy and insurance, so confirm the approved options before buying.
Replacing in pairs on the same axle is common to keep grip balanced; if all four are worn or you want consistent performance, replacing all four can be the better option.
Fitting options vary by area, but you can choose from available local garages during checkout and book the appointment time that suits you.
In the UK, tyres must have at least 1.6mm tread across the central three-quarters of the width around the full circumference; if you are near the limit, ordering replacements helps you stay road legal and MOT-ready.