Measure at the mid kneecap, directly on the skin with leg completely straight. Take a soft tape measure and in the center of the knee cap to get your circumfrence measurement.
S 13 to 13 7/8" M 14 to 14 7/8" L 15 to 15 7/8" XL 16 to 16 7/8" XX 17 to 18 1/8"
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