I measured my old belt that was worn out. It was cheap leather and worn out. Measured by the instructions and ordered the 38. It was a little bit short. Called Customer Service they recommended I go with a 40. Within Minutes I printed off a return label, carried it to the shipper they told me to go to, they provided the packaging and within a couple of days the new belt arrived and was a perfect fit. Customer Service is best I've ever seen! Best Quality leather and customer service around