Buying basics
Use unit prices without overlooking the real order
A simple calculation helps only when the products and purchase conditions are comparable.
By TPH LLC · Published October 25, 2026 · Research-based guidance
Choose the unit that answers your question
Decide whether you need a cost per sheet, roll, brief, bag, ounce, or another practical unit. Use the same unit for both offers. An outer box is rarely a useful unit if the boxes contain different quantities.
For paper products, sheets per roll can matter as much as the roll count. For laundry detergent, the stated load count depends on the label’s dosing basis. Compare the selected formula and use directions before treating advertised load counts as identical measures of use.
Work through an illustrative example
Suppose one hypothetical pack costs $12 for 60 items and another costs $18 for 120 items. The first is $0.20 per item; the second is $0.15 per item. These are invented arithmetic examples, not current prices for any product on the site.
Now add the conditions of the order. Delivery charges, minimum order thresholds, membership requirements, taxes, and a coupon or subscription can change the amount you actually pay. A one-time order and a recurring subscription should not be compared as though they make the same commitment.
Include practical limits
A lower unit cost is useful only if the product fits the intended task and the quantity is likely to be used. Consider available storage, how the package will be handled, and whether the selected size or variant may change before the supply is used.
Use the retailer’s current final order total for a purchasing decision. This catalog does not display live prices, calculate a guaranteed cheapest retailer, or promise that an advertised discount is available to every shopper. Record the calculation date if you keep a comparison for later.
Before you choose
- Same unit used for both offers
- Comparable product and variant selected
- Order conditions included
- Storage and expected use considered