One measurement is enough. Take a tape measure and measure the distance from your groin to your heel, feet flat on the floor.
Size M: up to 79 cm (up to 1.72 m). If you are under 1.65 m, choose size M and turn off the top chamber: the boots will fit you perfectly.
Size L: 80 to 100 cm (1.73 m to 1.94 m)
Size XXL: 101 cm and over (from 1.95 m)
Thigh circumference is not a selection criterion: our thigh extension kits (+10 cm of thigh circumference) widen any size if you have fuller thighs.
If you are between two sizes, always choose the larger one.
Note: we recently updated our naming. Size L corresponds to our former size XL. The dimensions are strictly identical.