215 is the tyre width in millimetres, 45 is the sidewall height as a percentage of the width, R means radial construction, and 16 is the wheel diameter in inches. Together, this describes a relatively wide, lower-profile tyre designed for 16 inch rims.
Check the size printed on your current tyre sidewall, then confirm it against the tyre label on the driver’s door shut or fuel flap, or your owner’s handbook. Some cars list multiple approved sizes, so match the exact size plus the specified load index and speed rating.
Not as a like-for-like swap, because the overall diameter and sidewall height differ, which can affect speedometer accuracy, ride comfort, and clearance around suspension and wheel arches. Only change if your vehicle manufacturer lists 215/45 R16 as an approved option, and inform your insurer if required.
Use the ratings shown on your vehicle placard or handbook and match them exactly, or choose higher if you prefer, but never lower. When comparing tyres, filter by the correct load index and speed rating first, then choose the brand and tread pattern that suits your driving.
They can be a strong option if you want one set to handle wet UK roads and cooler temperatures without changing tyres seasonally. If you drive mainly in summer conditions or want maximum warm-weather performance, a summer tyre may suit better, while frequent sub-7°C driving or snow-prone routes usually favours a winter tyre.