What is the legal tyre tread limit?

Cars, light vans and light trailers must have at least 1.6mm of tread depth across the central three-quarters of the tyre’s tread width and around the whole circumference.

The tyre must also be in a roadworthy condition. Adequate tread depth does not make a tyre safe if it has serious cuts, bulges, exposed cords or other dangerous damage.

How should you check tread depth?

Check several positions around each tyre rather than measuring in only one place. Uneven wear can leave one part of a tyre below the legal limit while another section still appears acceptable.

• Measure the main tread grooves across the central three-quarters of the tyre.
• Check at several points around the circumference.
• Inspect the tyre for cuts, bulges, cracking and visible damage at the same time.
• Check the inner edge of the tyre where possible, because uneven alignment or suspension wear can cause hidden wear.

Should you wait until a tyre reaches 1.6mm?

1.6mm is the legal minimum for the vehicle types above, not a target service depth. Wet-weather grip generally reduces as tread wears, so tyres should be inspected regularly and replaced when their condition or remaining tread makes replacement appropriate.

Different vehicle types can have different rules

Motorcycles, larger vehicles and some passenger-carrying vehicles have different tread-depth requirements. If you are checking anything other than a car, light van or light trailer, use the rules that apply to that vehicle class.

For the official UK requirements, see the Highway Code vehicle maintenance guidance.