Worn tire tread reduces grip in rain and increases stopping distance, so knowing how to check it keeps you safer on the road. This shows a couple of quick, no-cost ways to measure tread depth and spot uneven wear.
What you'll need
- A coin
- Tread depth gauge (optional)
Step by step
- Park and cool the tiresStop on level ground and let the tires cool if you have been driving. Turn the wheels outward slightly to reach the front tire faces more easily.
- Do the coin testInsert a coin into a tread groove with the edge pointing down. In the US, a penny with Lincoln's head down works; if you can see the top of his head, the tread is too low.
- Check multiple points on each tireTest the outer, middle, and inner grooves on every tire. Tread often wears unevenly, so one spot may be fine while another is worn.
- Use the built-in wear barsLook for the small raised rubber bars that sit across the grooves. When the tread is level with these bars, the tire has reached its wear limit.
- Measure with a gauge for accuracyFor a precise reading, press a tread depth gauge into a groove. Many regions treat 2/32 inch (about 1.6 mm) as the legal minimum.
- Note any uneven wearWear only on one edge or in the center points to alignment or inflation problems worth having checked.
Handy tips
- Replace tires before they hit the legal minimum, as grip drops well before that point in wet weather.
- Check tread at the same time as tire pressure, ideally once a month.
- Uneven wear across a set often means it is time for a rotation or alignment.
Heads up
- Driving on bald tires greatly raises the risk of skidding and blowouts, especially in rain or snow.
FAQ
What tread depth means I need new tires?
Many places set the legal minimum at 2/32 inch (1.6 mm), but replacing at around 4/32 inch gives better wet grip and a safety margin.
How often should I check my tread?
About once a month and before long trips is a good habit, along with checking tire pressure at the same time.
Why is my tire worn more on one side?
One-sided wear usually points to wheel alignment issues, while center or edge wear can mean over- or under-inflation. A shop can diagnose it.