A tire tread depth gauge is a tool used to accurately measure the depth of tread on a vehicles tire.

Tire tread depth gauges are usually either feature either digital or mechanical readouts. The most common and by far the cheapest is the mechanical style depth gauge. These usually consist of a small, pen-like device with a central plunger which can be depressed to provide an accurate measurement from the top of the tire tread down into the grooves.