Why You Need To Measure Tire Tread Depth A tire with only 3/32" or 4/32" of tread may be allowed on the road legally, but that doesn't mean it's ideal, especially in wet or winter conditions. The ...

The tire tread depth is the measurement between the groove (the gap between the patterned rubber) and the top of the tire tread. For new tires, this depth is usually 10/32 or 11/32 inches (8 or 9 mm).

It's a major part of determining how safe, effective, and long-lasting your tires are, and yet it's rarely ever discussed. In the United States, tread depth is measured in 32nds of an inch.