A borescope calibration device is provided that includes a base having a planar surface and a plurality of reference surfaces on a side of the base opposing the planar surface, each of the plurality of reference surfaces having a height that decreases along a length of the base, a fixture that positions an optical head along a reference line that is parallel to the planar surface and providing a fixed distance between the reference surfaces and the optical head, the fixture being movable along a length of the base, and a target pattern formed on each of the reference surfaces.