While the product page says the boots have a fourteen inch opening, the laces will loosen up to fit a much larger calf. My calves measure 16.5 inches at the widest point and these boots still fir perfectly, even to the point where I can wear them over jeans. They are also super lightweight, though I will be getting a pair of insoles, though I have lousy feet. Foot portion seems to fit very true to size and the material feels great to the touch. Can't wait to wear these!