How to Read Unit Price Labels

A typical shelf tag shows two prices. The big one is what you pay for the package. The small one is the unit price: the cost per standard unit, such as per ounce, per pound, per 100 g, per liter or per count.

Example: a 24 oz jar for $4.79 might show a unit price of $0.20 per ounce, because $4.79 ÷ 24 ≈ $0.20. The jar next to it might be 32 oz for $5.99, or about $0.19 per ounce. The bigger jar is slightly cheaper per ounce even though its shelf price is higher.

Unit prices only help when they use the same unit, and neighboring tags sometimes don’t: one product per ounce, the next per pound or per count. Before comparing, check the small print after the number. Per pound is 16 times per ounce; per kg is 10 times per 100 g. Or enter both products in the calculator below — it converts them for you.

Sale stickers and loyalty-card prices aren’t always reflected in the unit price printed on the regular tag. If a product is on sale, work out the unit price from the sale price — that is often when a smaller pack beats the bulk size.

Eggs, batteries, diapers and paper towels may show a price per count — per item, per sheet or per load. That is useful within one product type but can mislead between brands whose items differ in size: a “double roll” isn’t a standard size. The toilet paper calculator compares per sheet instead.

Not every product or store shows a unit price, and tags can be faded, hidden behind another product or out of date. Take the price and the net weight from the package itself and enter them in the calculator: it takes a few seconds and works with any unit.

A lower unit price is only a better deal if you use the whole package. Quality, ingredients and how much you really need matter too. The unit price answers “which is cheaper per unit?” — not “which is better for me?”. Keep an eye on the net weight of products you buy often, too: a smaller pack at the same price is shrinkflation.