Price Per Unit Calculator
Compare two package sizes by unit price and see which is the better deal — and by how much.
How it works
unit price = price ÷ quantity — lower unit price wins · savings % = (higher − lower) ÷ higher × 100
Dividing each price by its package quantity puts both items on the same scale, no matter how different the package sizes are. The percentage shows how much less you pay per unit by picking the cheaper one. Any unit works — ounces, pounds, sheets, loads — as long as both items are measured in the same one.
Worked example
Item A: $4.99 for 12 oz = $0.416/oz. Item B: $7.49 for 20 oz = $0.375/oz. Item B is the better deal, about 9.9% cheaper per ounce despite the higher shelf price.
Frequently asked questions
Don’t shelf tags already show unit price?
Usually, but not always in the same units — one brand per ounce, its neighbor per pound or per 100 sheets, which makes tag-to-tag comparison useless. Recomputing in one unit is the fix.
Is the bigger package always cheaper per unit?
Often but not reliably — "shrinkflation" and promotions regularly make the mid-size or sale-priced small pack the true winner. Check rather than assume.
What about comparing different brands or concentrations?
Compare per use, not per volume: a concentrated detergent with 64 loads in 50 oz beats a watery one with 32 loads in the same bottle. Use loads or servings as the quantity.
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This calculator is for educational purposes. Double-check important results before acting on them.