Measure circumference of thigh 4.5" above the knee. Size Thigh Circumference Approx. Age Child SM/MD 7" to 9.5" (17.7 to 24cm) 1.5 to 2.5 years Child LG/XL 9" to 11.5" (22.8 to 29cm) 3 to 4 years * Because the same age children have different size legs, we strongly recommend sizing by thigh circumference, not age.
