How to use this calculator
- Enter the price and amount for Product A and Product B.
- Choose the same unit for both products.
- Check each price per unit, the difference, and the product with the lower unit price.
Example: Two package sizes
A 14 oz product at $4.99 costs about $0.3564 per oz. A 20 oz product at $6.49 costs about $0.3245 per oz.
Product B has the lower unit price, by about 8.9%. It costs more at checkout, but less for each ounce.
Make a fair comparison
Convert package sizes to the same unit before comparing. For example, compare ounces with ounces or milliliters with milliliters. The lower unit price is useful, but it does not account for whether you will use the whole package, product quality, or a deal that applies only to one item.
Frequently asked questions
Can I compare different units?
Yes, after converting them to one common unit. For example, enter 32 oz rather than 2 lb, or 1,000 ml rather than 1 liter.
Does a lower unit price always mean I should buy the bigger package?
Not always. It is only a price comparison. Consider expiration, storage, how much you will actually use, and the total amount you need to spend today.