What is the minimum legal tire tread depth in inches?

• A. 1/8
• B. 1/16
• C. 1/32
• D. 1/4

Answer: (B)

Tire tread depth matters because it determines how well your tires grip the road and move water away from the contact patch. The minimum legal depth is one sixteenth of an inch, which is the same as two thirty-seconds. If tread wears down to that level or less, tires are considered unsafe and can be illegal to drive on public roads. You can check using a tread depth gauge, or a quick pass with a penny test: insert the coin into the grooves with Lincoln’s head upside down—if you can see the top of Lincoln’s head, the tread is below the minimum and needs replacement. Replacing tires before they reach this limit improves wet-weather traction and overall safety.