Abstract: Disclosed is a multi-purpose measuring gauge in which three probes are secured to and movable with respect to a T-shaped housing. Two outer probes are secured to members which are slideable along parallel slots in the housing. The probe members comprise a rack and are moved by a pinion. The pinion is coupled to a micrometer caliper. The dual travel of the rack and pinion thereby retains the respective relationship between the two probes and the third probe, which is disposed equidistant between the two probes. The stem of the T of the housing has therethrough the third probe. All of the axes of the probes are parallel. The ends of the two outer probes are co-planar. The third probe is moved perpendicularly with respect to that plane by means of another micrometer caliper rotatably secured to the housing. The facing sides of the two outer probes are planar to aid in making measurements. Indicia on each caliper provides a direct reading to make a variety of measurements.