When taking measures of the width, you want to make sure you measure the widest part of the hoof. The width of the hoof determines the size of the boot ("SG" 3-8).
When taking measures of the length, make sure you measure from the tip of the toe to the end of the bulbs. The length of the hoof determines whether you need a "SG" or a "SG-L".
When taking measures of the height, make sure you measure from the ground to the deepest part of the pastern. A specific height will indicate which boot type ("SG oder "SG-L") is needed.
CAUTION: Please make sure to thoroughly measure in a 90° angle. The image below shows how it should not be done :-) A "wrong" angle can impact the measurements in an unbeneficial way.
HOW TO MEASURE YOUR HORSES HOOVES
EASY+QUICK ON´N OFF
"HOLY MOLY!! First, these boots have the best traits of every other brand, mooshed into one boot. They have a supportive heel bulb, a soft, flexible yet durable plastic mold (thermoplastic polyuretherane), awesome tread, heel protecting neoprene with a plastic protector and adjustable heel bulb height and toe tightness. The biggest change we found was the boots STAYED ON and my horse stopped over reaching."