Unit price calculator — compare pack sizes and quantities

A cheaper pack may cost more for the same amount. Enter price, quantity per item and pack count to compare like with like.

Formula and worked example

Unit price = price ÷ (quantity per item × pack count). If A costs 6 for one 500 g item, and B costs 15 for two 750 g items, A costs 1.20 per 100 g and B costs 1.00 per 100 g. B has a unit price about 16.67% lower than A. Total spend and unit price are different comparisons.

Which units can you compare?

Grams and kilograms are normalized to a price per 100 g. Millilitres and litres use a price per 100 mL. Counts use a price per item. We use 1 kg = 1,000 g and 1 L = 1,000 mL. Mass and volume need density to convert, so we do not mix them. Enter both prices in the same currency.

Discounts, shipping and tax

Enter the final amount you want to compare as the price. Coupons, tax, delivery charges, membership offers and currency conversion are not applied automatically. Pack count is the total number of items; quantity is the amount in one item. Keeping them separate prevents counting the pack twice.

Is the bigger pack always better?

Unit price compares only the cost of the same amount. Quality, storage space, expiry dates and waste are outside the model. A lower unit price can still mean higher spending if you cannot use the whole pack. Displayed values are rounded; comparisons use unrounded values.