I have size 4, narrow feet, slim ankles but wide calves (even at my slimmest I've never had standard boots fit). However if I try on a pair in a size 6 or above they usually zip up just fine which is really frustrating. They are slightly over 15inches in circumference meaning I should fit into standard boots but no hope in a size 4! Is it worth trying to stretch them? When I get wide fit boots they are baggy around the ankle.