A flat transparent overlay for measurement of equine foot x-rays employs a flat lower edge for alignment with a ground surface and an anterior edge angled to approximate a hoof distal wall. A first sight ring positions the tool over a tip of an image of a third phalanx. Six interrelated scales are provided for measurement of the palmar cortex, distal sole thickness, break-over distance and coronet band to extensor process distance, and in conjunction with a second site ring, center of rotation and palmar sole thickness. A first protractor element is centered posterior on the first sight ring for measurement of the palmar angle. A dual scale extends from the angled anterior edge portion with a measurement line for measurement of the hoof-lamella zone. A second protractor element is posterior to and centered on the second sight ring for measurement of a pastern angle.