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 27.5 - 32.5
M 24.5 - 30.5 29.0 - 34.5
L 26.0 - 32.5 31.0 - 36.5

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