This depends on the factors such as, how often do you use the shampoo bar, hair length and how you store your shampoo bar. Shampoo bar last longer if they are kept dry between washes. If you just use it as hair shampoo or as the one bar from head to toe (yes, our shampoo bars can be used as a face and body bar as well). From the experience of our users, the 75g shampoo bars can last between 50 to 80 washes and the 50g shampoo bars can last between 30 to 50 washes. Our sampler shampoo bars weigh 30g and can last between 20-30 washes.