I have even longer hair. I have very blonde hair that is so long its longer than I am tall. I take very good care of it. My hair is very shiny and very healthy.Guys always compliment me and tell me how beautiful my floor length natural platinum blonde hair and girls always tell me how they wish they had hair as long, blonde, shiny, and beautiful as mine. I'm sure guys would love your hair at knee length as long as you took good care of it.