NOTICE: Most people need either of the first two sizes. Sizing is based on a measurement of the calf approximately 15cm below your patella. For best results, ensure the knee is bent at approixmately 30 degrees.
X-Small 11.8 to 12.6in (30-32cm)
Small 12.6 to 13.4in (32-34cm)
Medium 13.4 to 14.2in (34-36cm)
Large 14.2 to 15in (36-38cm)
X-Large 15 to 15.7in (38-40cm)