Sit in a straight chair with your knees bent at 90 degrees to the floor.
Wear the breeches and socks that you would most likely wear with your tall boots.
Have someone else measure your calves, if possible:
A. Measure foot for shoe size. B. To determine calf width: Measure the calf width at the widest part of the calf. C. To determine calf height: Measure leg height from the floor to the bend behind the knee.
Add approximately ½”–¾” to allow for drop.
Approximate drop allowance is built into the chart height measurements so make sure you add drop to your leg measurement.
Normally I have problems with fitting leather riding boots over my muscular calves but not with these. In fact, the regular seems almost too big and wrinkles at my ankles and need to be pulled up. Otherwise, they are very comfortable and required no break in time.