Compression sizing isn't standardised across brands — a Medium in one brand is often not a Medium in another, so go by your measurements rather than the size you wore last. Measure your ankle at its narrowest point and your calf at its widest, first thing in the morning before swelling builds, against bare skin with your foot flat and the tape snug but not constricting. If your swelling has changed, or you've gained or lost weight, or you're recovering from surgery, re-measure rather than reordering your previous size. Our measuring guide walks through each measurement.