Unit Price Calculator (Which Is the Better Deal?)
Updated · Written and checked by Monu Kumar Modi · How we check our maths
Quick answer
Unit price = price ÷ quantity. A 32 oz pack at $6.49 costs about 20.3¢ per ounce, while a 48 oz pack at $8.99 costs 18.7¢, so the larger pack is about 7.7% cheaper per ounce and saves $0.75 across 48 oz.
How this calculator works
Packs come in odd sizes, so the sticker price rarely tells you which is cheaper. The unit price, price per ounce, gram, millilitre or item, puts them on equal terms. Many shelf labels show it, but often in different units for different brands.
Enter both prices and quantities in the same unit. The calculator shows each unit price, which one is cheaper and by how much, and the money saved if you bought the larger amount at the cheaper rate.
Bigger isn't always cheaper: multi-buy offers, discounts on small packs and 'family size' labels can all flip the result. It's only a saving if you will use it before it goes off.
The formula
- Unit price
- price ÷ quantity
- Saving %
- (higher unit price − lower) ÷ higher × 100
Worked example
$6.49 ÷ 32 oz = $0.2028 per oz. $8.99 ÷ 48 oz = $0.1873 per oz. Item B is 7.7% cheaper per ounce, saving about $0.75 across 48 oz.
Tips
- 01Convert to the same unit first: 1 lb = 16 oz, 1 kg = 1,000 g, 1 litre = 1,000 ml.
- 02Check the unit price on the shelf label, but confirm both labels use the same unit.
- 03Store brands often have the lowest unit price for staples.
Frequently asked questions
How do I calculate unit price?
Divide the price by the quantity, for example $6.49 ÷ 32 oz = about 20 cents per ounce.
Is buying in bulk always cheaper?
Usually per unit, but not always. Sales on smaller packs can be cheaper, and bulk only saves money if you use it all.
What unit should I compare?
Any unit, as long as both items use the same one: weight for food, volume for liquids, count for items like nappies or batteries.