Measure once, compare more fairly
Use the amount you actually apply. If you shampoo twice, add both applications when you want the cost of a complete wash. For a mask used every other wash, enter the number of times you use that mask each week.
A pump or spray is not a fixed unit. Measure your usual set of pumps in mL, or weigh the amount in grams, before entering it here. Choose the matching bottle unit.
Keep weight and volume separate
US fluid ounces and mL measure volume. Net-weight ounces and grams measure weight. This calculator converts within the same measurement type, but never turns an 8 oz jar into 8 fl oz. That would require knowing the product’s density.
Formula: cost per use = price × amount per use ÷ bottle amount. Full uses are rounded down; a partial dose does not count as another complete use.