The size of your hand determines what height is best fit for you. For the most accurate results, measure your hand size in inches with a ruler. Start from the outer-most tip of your thumb and extend to the outer-most tip of your pinky. Small: 5.9-7in / 15-17.8cm Medium: 7-9in / 17.8-22.9cm Large: 9-10.5in / 22.9-26.7cm