A depth gauge is an instrument used to measure the depth of a bored hole, drilled hole, or cut. A precision-built measuring tool that can give the depth reading in a variety of measurements. It is a critical tool used in many machining processes, from automotive engines to surgical tools and ceramics.

A depth caliper is composed of a graduated rod and an adjusted base, which rests on the top of the hole. The special feature of a depth caliper is its large supporting base that prevents the almost total inclination of the caliper, and consequently any measurement error. In the digital version, the measured value is easily readable on the large LCD.