Unit Price Calculator

How to use the Unit Price Calculator

1. For each product, enter the shelf price you'd pay and the package size (for example 1 × 24 oz, or 6 × 12 fl oz cans).
2. Pick the unit printed on the label. You can mix ounces, pounds, grams and kilograms, or fluid ounces, liters and gallons.
3. If you have a coupon, enter it as dollars off or percent off for that product.
4. Choose how to show the result: per ounce, per 100 g, per liter, per item and so on.
5. The best value is highlighted, along with how much more the others cost per unit and what you'd save buying the same amount.

How it works

The calculator turns every product into the same base unit before comparing. Weights are converted to grams using the exact international definitions (1 oz = 28.349523125 g and 1 lb = 453.59237 g). Volumes are converted to milliliters using US customary measures (1 US fl oz = 29.5735295625 mL, 1 cup = 8 fl oz and 1 gallon = 3.785411784 L). Counts such as items, sheets, rolls or loads are compared only with the same kind of count, because a roll and a sheet aren't the same amount of product.

For each product: price you pay = shelf price minus any coupon, and total amount = number of packs × size of each. The unit price is the price you pay divided by the total amount, shown per the unit you choose. The cheapest unit price wins. The "you'd save" figure answers a practical question: if you bought the same total amount as the other product but at the best product's unit price, how much less would you spend?

Worked example: a 24 oz jar for $4.29 costs $4.29 ÷ 24 = about $0.179 per ounce. A 1 kg jar for $6.49 is 35.27 oz, or about $0.184 per ounce. The smaller jar is about 2.8% cheaper per ounce, so on 35.27 oz you\'d save roughly $0.18. Weight and volume can\'t be compared directly (an ounce of honey and a fluid ounce of honey are different amounts), so the calculator asks you to use one kind of unit for all products.

Frequently asked questions

What does the percentage mean?
It shows how much cheaper the best product is per unit compared with each other product. If one costs $0.20/oz and the best costs $0.15/oz, the best is 25% cheaper per ounce.

Can I compare ounces with fluid ounces?
No. Ounces measure weight and fluid ounces measure volume, and the conversion between them depends on the product's density. Check the label: most packages list both a weight or volume and a metric amount, so pick the same kind for each product.

How should I enter multipacks?
Enter the number of packs or bottles as Packs and the size of one as Size each. A 12-pack of 12 fl oz cans is 12 × 12 fl oz = 144 fl oz.

Is the bigger package always cheaper?
Often, but not always, especially when a smaller size is on sale or has a coupon. And a lower unit price is only a saving if you'll use the extra before it goes bad.

Does it include sales tax?
No. Enter shelf prices. Tax is usually the same percentage on each item, so it doesn't change which one is cheaper. To work out tax, use the Sales Tax Calculator.