Published 2026-04-20 · TT Mobile Tyre Fitting 24/7
Your tyre tread depth is one of the most important safety checks you can do on your car, and it takes about 30 seconds. Here is how to do it correctly.
The UK legal minimum tread depth for cars is 1.6mm across the central three-quarters of the tyre, around the entire circumference. Driving on tyres below this limit is illegal and carries a fine of up to £2,500 per tyre and three penalty points per tyre — that is a potential £10,000 fine and 12 points for a full set of worn tyres.
More importantly, tyres worn below the legal limit have significantly reduced grip, particularly on wet roads. Independent tests show that wet-weather braking distances increase dramatically as tread depth falls below 3mm — not 1.6mm. Most tyre safety organisations recommend replacing tyres at 3mm rather than waiting for the legal minimum.
The quickest way to check your tread is the 20p coin test. Take a 20p coin and insert it into the tread grooves. If the outer band of the coin is hidden when the coin is inserted, your tread is above 1.6mm and legally acceptable. If you can see the outer band, the tread is too low and the tyre needs replacing.
For a more accurate reading, use a tread depth gauge — available from any motor accessory shop for a few pounds. Insert the probe into the tread groove and read the measurement. Check across the width of the tyre and in multiple places around the circumference — wear is not always even.
Look for uneven wear patterns while you check. Wear concentrated in the centre of the tread suggests the tyre has been over-inflated. Wear on both edges with a good centre suggests under-inflation. Wear on one edge only usually indicates a wheel alignment problem. These patterns tell you something is wrong beyond just tread depth.
If you are in any doubt about your tyre condition, call TT Mobile Tyre Fitting 24/7 on 07762 455291. We can come to your home or workplace anywhere across Birmingham, Wolverhampton, Walsall, Dudley, Coventry and the surrounding West Midlands and check your tyres on the spot. If they need replacing, we can do it right there and then.