Pick a measure type, then enter the price and quantity for each option.
Bigger packages usually — but not always — work out cheaper per unit. Store shelf labels sometimes show a unit price, but they don't always use the same base unit across brands or package sizes, which makes two products genuinely hard to compare at a glance.
This calculator converts both options to the same base unit — grams for weight, millilitres for volume, or a flat per-item rate for count-based products like eggs or rolls of paper towels — so you're always comparing like with like, regardless of whether one package is labelled in ounces and the other in grams.
The percentage saved is calculated relative to the more expensive option's per-unit price, so you can see immediately how much of a discount the cheaper option actually represents rather than just which number is smaller.
Pick the matching measure type (Weight, Volume, or Count) and choose each option's own unit from its dropdown — the calculator converts both to a common base unit automatically before comparing.
Not always. Bulk sizes are often cheaper per unit, but promotional pricing, private-label brands, or multi-buy deals on smaller packages can sometimes beat the bulk option — that's exactly why comparing the actual unit price matters.
Yes — it works for anything sold by weight, volume, or item count, such as cleaning supplies, pet food, toiletries, or office paper.
It's the difference between the two per-unit prices, shown as a percentage of the more expensive option — so 'Option A is 15% cheaper per unit' means you pay 15% less per gram/ml/item choosing A over B.
