Abstract: A radiographic image scaling device comprises a mounting unit and a reference object attached to the mounting unit. The reference object has a known actual size and shape and a sufficient radio-opacity to be visibly measurable in a radiographic image. The mounting unit has a radio-opacity that is different than that of the reference object, and a rigid body with at least one curved portion engagable with a surface for receiving a subject. The reference object is attached to a location on the mounting unit body that incremental movement of the mounting unit relative to the surface along the curved portion causes the reference object to incrementally move relative to the surface. Particularly, the reference object can be radio-opaque and the mounting unit can be is radiolucent.