Work out price comparison (2 items) instantly with clear inputs, formula shown and shareable results.
Dividing price by quantity gives the only figure that compares directly. Expressing the gap as a percentage of the dearer option makes it concrete: a 10% unit price difference on a weekly purchase is real money over a year.
Unit comparison
unit price = price / quantity; saving = 1 - cheaper / dearer
Then unit price is only part of the answer. Adjust for quality, size or concentration before comparing, or you are pricing different things.
Because absolute pennies mean little without context. A percentage tells you whether it is worth changing habits.