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

Brand Size Waist (inch) Hip (inch)
S-M 26.5 - 31.0 35.0 - 38.0
L-XL 28.0 - 33.0 36.5 - 40.0

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