Compare prices by the ounce, pound, or any unit to find the best deal.
Unit price is the cost per standard unit of measurement (per ounce, per gram, per count, per liter). It allows direct comparison between products sold in different package sizes. A 24-ounce jar of pasta sauce for $3.99 costs $0.166 per ounce, while a 48-ounce jar for $6.49 costs $0.135 per ounce. The larger jar is 19% cheaper per ounce even though the sticker price is higher. This calculator compares up to several products side by side.
Bulk buying saves money per unit, but only if you use everything before it expires or goes stale. Perishable items like dairy, produce, and bread often go to waste in larger quantities. A gallon of milk at $0.04 per ounce beats a quart at $0.06 per ounce, but not if you throw away a third of the gallon. For shelf-stable items like canned goods, rice, and cleaning supplies, larger sizes almost always offer better unit prices with no spoilage risk.
Store brands and generics typically have lower unit prices than name brands by 20 to 40%. In many product categories (canned vegetables, over-the-counter medications, cleaning products, pantry staples), store brands are manufactured by the same companies that produce the name-brand versions. Comparing unit prices between brands reveals the actual premium you pay for packaging and marketing.
Most U.S. states require grocery stores to display unit prices on shelf tags. The displayed unit (per ounce, per 100 count, per quart) should be consistent within a product category so consumers can compare easily. However, not all stores comply perfectly, and online grocery platforms sometimes omit unit pricing entirely. This calculator fills that gap by letting you enter any two products and see the per-unit comparison regardless of how they are sold.
The Discount Calculator is useful when sale prices change the unit-price math. A 20% coupon on the smaller jar might make it cheaper per ounce than the regular-priced larger jar. Always recalculate unit prices after applying coupons or discounts to find the true best deal.
Warehouse clubs like Costco and Sam's Club sell in bulk at lower unit prices, but the annual membership fee ($50 to $65 for basic, $120 for premium) must be factored into the savings calculation. If bulk purchases save you $0.02 per ounce on items you buy regularly, you need to purchase enough total ounces over the year for the cumulative savings to exceed the membership cost. For a family spending $200 to $300 per month on groceries, the membership typically pays for itself within a few months through unit price savings on staples like paper products, cleaning supplies, meat, and dairy.
The bigger package isn't always cheaper per unit. Stores sometimes price medium sizes at a lower unit cost than bulk to catch shoppers who assume bigger equals better. This calculator compares any two (or more) products by converting them to the same unit so you can see which one actually costs less per ounce, per count, or per serving.
Unit pricing is especially useful for groceries, cleaning supplies, pet food, and personal care products where packaging sizes vary wildly. A 32oz bottle at $4.99 vs a 50oz bottle at $8.49? This calculator tells you instantly which is the better deal, no mental math required.