How to Check Your Tyre Tread Depth at Home

Your tyres are the only part of your car that touches the road. That narrow strip of rubber — typically about the size of your hand for each tyre — is responsible for all braking, acceleration, and cornering grip. When your tread depth drops too low, that grip disappears rapidly, especially in wet conditions.

In the UK, the legal minimum tread depth is 1.6mm across the central three-quarters of the tyre. Drive on tyres below this limit and you risk a £2,500 fine and three penalty points per tyre. More importantly, your stopping distances increase dramatically — a car stopping from 50mph on worn tyres can need up to 36 metres more than one on new tyres.

The simplest way to check tread depth at home requires nothing more than a 20p coin. Take the coin and insert it into the main tread grooves of your tyre. If the outer band of the coin is hidden when it's inserted, your tread is above the legal limit. If you can see the outer band clearly, your tyres may be illegal and you should get them checked by a professional immediately.

Do this test at multiple points around the circumference of each tyre and across the width of the tread. Uneven wear can mean one section of the tyre is dangerously worn even if other sections look fine. Check all four tyres — don't assume because the fronts look good that the rears are in the same condition.

While 1.6mm is the legal minimum, most tyre safety experts recommend replacing tyres at 3mm. Below 3mm, wet weather performance degrades significantly. The difference between 3mm and 1.6mm in stopping distances in the rain is considerable — and in an emergency stop, those extra metres could be the difference between a near miss and a collision.

If you're not confident checking your own tyres, most mobile tyre fitters — including us — offer a free tyre inspection. We can check tread depth, tyre age, sidewall condition, and inflation at your home or workplace. Don't wait until your tyres are obviously worn before getting them checked.