Unit Price Comparison Calculator

About this calculator

A product's unit price — cost per ounce, per litre, per 100 grams, or whatever base unit fits the item — strips away the effect of package size so two differently-sized products can be compared on equal footing, which the sticker price alone can't do: a larger package isn't automatically the better deal, and "buy in bulk to save" isn't always true. The calculation itself is simple division, total price ÷ total quantity, but doing it consistently across two products with different package sizes and sometimes different units is where shoppers actually go wrong.

Many countries legally require grocery stores to display unit pricing on shelf labels for exactly this reason — consumer protection research consistently shows shoppers overestimate how much bulk packaging saves them, and retailers sometimes price the "value size" worse per unit than the regular size to capitalize on that assumption. Comparison shoppers use unit-price calculations not just at the grocery store but for anything sold in varying package sizes: cleaning supplies, pet food, cosmetics and even subscription services priced per unit of usage.

This calculator compares two products by their price and quantity and tells you which one is the cheaper deal per unit.