Well, with the backcomb-and-wax method of creating locks, you should be comfortable losing anywhere from 1/3 to half of your length. The harder you have to backcomb your hair (say for fine fine hair) the more length you’ll lose. If you’re worried about keeping your length, or you want to add extra length, contact the KB Lock Shop – the methods used in the salon allow you to keep waaaaay more of it, and they can extend your new locks seamlessly.