Measure the narrowest part of your waist and the widest part of your hips and buttocks.

Brand Size Waist (inch) Hip (inch)
S 23.5 - 28.5 28.0 - 33.5
M 24.5 - 30.5 30.0 - 35.5
L 26.0 - 32.5 32.0 - 37.5

Natural silk has little stretch. Size up for the best fit.