Unit Price Calculator
Compare two products by price per unit to see which size or pack is the better deal.
Why unit price matters
Packs come in different sizes, so the sticker price does not tell you which is cheaper. Dividing the price by the quantity gives the unit price, which makes any two options directly comparable.
Unit price = Price ÷ Quantity
A 12 oz jar for $4.99 costs 41.6¢ per ounce. A 24 oz jar for $8.49 costs 35.4¢ per ounce, so the larger jar is about 15% cheaper per ounce.
Bigger is not always cheaper
Supermarket studies regularly find cases where a larger pack costs more per unit than a smaller one, especially when the smaller size is on promotion. Multi-buy offers such as "3 for $10" also need checking against the single-item price.
Tips
- Use the same unit for both items. Convert grams to ounces or liters to fluid ounces with the converters if needed.
- Many stores print the unit price on the shelf label; check that both labels use the same unit.
- A cheaper unit price only saves money if you will use the extra amount before it spoils.
Frequently asked questions
How do I calculate unit price?
Divide the price by the quantity. A $6 pack of 4 has a unit price of $1.50 each.
Is buying in bulk always cheaper?
No. It often is, but promotions on smaller sizes can make them cheaper per unit. Always compare.
What units should I use?
Any unit, as long as both items use the same one: ounces, grams, sheets, loads or items.
Last reviewed Oct 20, 2026. Results are estimates; check important decisions with a qualified professional.