Everyday Life
How to check your tyre tread depth
Learn how to measure your tyre tread depth accurately using simple tools and know when to replace your tyres for safety.
Written by Robert Hayes · Reviewed by Rachel Turner · Updated October 31, 2026 · 3 min read
Immediate actions
- 1 Use a tread depth gauge or a 20p coin to measure the tread depth.
- 2 Check tread depth in at least three locations across the tyre width.
- 3 Replace tyres when tread depth reaches 1.6mm (the legal minimum).
- 4 Inspect tyres regularly, especially before long journeys or in wet weather.
What not to do / warning
Worn tyres significantly increase stopping distances and the risk of accidents, especially in wet conditions. Replace tyres when tread depth reaches 1.6mm or sooner if performance is compromised.
Tyre tread depth is critical for safe driving, especially in wet conditions. Worn tyres increase stopping distances and the risk of aquaplaning. This guide shows you how to check your tread depth accurately and know when to replace your tyres.
What is tyre tread depth?
Tread depth is the height of the rubber blocks on your tyre from the bottom of the grooves to the surface. It is measured in millimetres. The legal minimum tread depth for cars in the UK is 1.6mm across the central three-quarters of the tyre around its entire circumference. However, safety experts recommend replacing tyres at 3mm for better wet grip.
How to check your tyre tread depth
- Gather your tools: You can use a tread depth gauge (available at auto parts stores) or a 20p coin. A gauge gives a precise measurement, while the coin method is a quick check.
- Park safely: Ensure your car is on a flat, stable surface with the handbrake on and engine off.
- Locate the tread wear indicators: These are small raised bars inside the main grooves. If the tread is level with these bars, the tyre is worn to 1.6mm and must be replaced.
- Measure with a gauge: Insert the gauge into the groove and press down until the base is flat against the tread. Read the measurement. Repeat at three points across the tyre width (inner, centre, outer) and at several points around the circumference.
- Use the 20p coin method: Insert a 20p coin into the tread groove. If the outer band of the coin is visible, the tread depth is likely below 1.6mm. Check in multiple locations.
- Record your findings: Note the lowest measurement. If any measurement is at or below 1.6mm, replace the tyre immediately. If it is between 1.6mm and 3mm, plan for replacement soon.
What NOT to do
- Do not rely on a visual check alone; tread may look adequate but be worn unevenly.
- Do not check only one spot on the tyre; wear can vary across the width and circumference.
- Do not ignore uneven wear patterns; they may indicate alignment or suspension problems.
- Do not use tyres with cuts, bulges, or exposed cords; replace them immediately.
When to seek professional help
If you are unsure about the condition of your tyres, or if you notice uneven wear, vibrations, or handling issues, have a professional inspect your tyres and wheel alignment. Many tyre shops offer free tread depth checks.
How to prevent premature tread wear
- Maintain correct tyre pressures; check them monthly and before long trips.
- Rotate tyres according to your vehicle manufacturer's schedule.
- Avoid aggressive acceleration, braking, and cornering.
- Have wheel alignment checked if you notice uneven wear.
Regular tread depth checks are a simple but vital part of vehicle maintenance. Make it a habit to check your tyres monthly and before long journeys. If in doubt, consult a qualified tyre technician.