Detergent washes per pack calculator
Read two numbers on the label: the size of the pack and the dose to use for one wash. The calculator divides one by the other and gives the number of full washes in the pack.
Add how many washes you run per week to see how many weeks the pack lasts. Leave that field empty if you only need the number of washes.
Enter the pack size and the dose, then calculate.
Method and limitations
Full washes = pack size ÷ dose per wash, rounded down to a whole wash. Imperial: the pack size and the dose are in the same unit, fluid ounces for a liquid or ounces for a powder, so no conversion is needed. Metric: the pack size is in liters (liquid) or kilograms (powder) and the dose in milliliters (liquid) or grams (powder), with 1 L = 1,000 mL and 1 kg = 1,000 g. Weeks of supply = full washes ÷ washes per week. Both figures depend on the product, so none is assumed: type the ones printed on the label of the product you buy. The result does not account for hard water, heavy soil or a different dose chosen for a given load. This is an arithmetic calculation, so no external source is needed.
Sources
No external reference is documented for this calculation; its method and limitations are described above.
