Unit pricing: the grocery math that beats most coupons
The shelf tag at most supermarkets shows two prices: what the package costs and what it costs per unit (per ounce, per pound, per count, or per 100 sheets). The unit price is the single fastest way to compare sizes and brands. Many shoppers never look at it.
How to use it
- Find the small "unit price" box on the shelf tag.
- Compare items using the same unit. If one tag says per ounce and another says per pound, convert first (16 ounces = 1 pound).
- Pick the lowest unit price among the items you would actually use.
Common traps
- Bigger isn't always cheaper. Sale prices on smaller sizes often beat the "family size."
- Mixed units. Paper towels and toilet paper may be priced per roll or per sheet, and rolls come in different sizes. Per-sheet or per-square-foot is the honest comparison.
- Sale tags. A yellow sale tag sometimes doesn't show a unit price for the sale price. Do the quick division yourself: price ÷ quantity.
- Waste. A cheaper unit price doesn't help if half of it spoils. Buy bulk only for things you'll finish.
Who sets the rules?
Unit pricing is regulated at the state and local level, not by one national law, so requirements vary. The National Institute of Standards and Technology's Office of Weights and Measures publishes model regulations that many states adopt and supports state inspectors who check that packages contain what the label says.
Stack it with coupons
Do the unit-price comparison first, then apply coupons. A coupon on the expensive brand only wins if the price after the coupon gives a lower unit price than the store brand. Our coupon stacking guide covers how to combine store and manufacturer coupons.
More: today's deals · is that sale real?
Published October 25, 2026. Some links may be affiliate links; see our Affiliate Disclosure.