Your hair might grow slower or faster than that, which contributes to how long your hair can get if you let it go. If your hair is past your shoulders, your ends are probably more than three years old! Just think about all the abuse they’ve sustained in that time, like scorching sun exposure, relentless heat styling, dips in salt water and chlorine, color treatments and aggressive brushing. Treat your locks right: Wash gently in not-too-hot water and don’t blow-dry every day. Your hair has been through enough already.