The cap sits on your head, the bill sits at the top of your forehead. There really is no space between the top of your head and the cap. Guess the cap is as tall as your head is tall.

Yes and no. I got a smudge of dirt on mine and used a cloth with a little liquid detergent on it and wiped it out. I haven't not would I because of the rhinestones put it in a washing machine.