I measured my left calf at it's widest point wearing jeans and it is 14 inches. I could tighten the strap to the tightest notch, but it was snug (I also think it looks sort of warped funny when the bottom strap is on the tightest notch...having the top strap only tightened looks fine). I typically wear the middle notch of the three for the left side. My right calf is 14.5 inches and on that side I have the top strap on the loosest notch. I have the size 7.