Chevy4Life, if you prefer a snug boot, I do not recommend ordering larger. Please keep in mind that this is only a guideline, and I cannot guarantee what size will be needed.
Here is the size breakdown for the Jel insert:
Men?s sizing: S(6), M(7-9), L(10-11), XL(12-14)
Women?s sizing: S(6-8), M(9-11), L(12)