Unit price calculator

Try the example by hand

Example, not a live offer: a 12 oz pack at $4.79 costs $0.3992 per oz. An 18 oz pack at $6.49 costs $0.3606 per oz. The larger pack costs about 9.67% less per ounce, even though it costs $1.70 more at checkout.

How the comparison works

For each option, divide the total price by the size of one pack multiplied by the number of packs. The calculator converts compatible units before dividing. The percentage saving is the difference between the two unit prices divided by the higher unit price.

The price field is for the entire bundle. For three 8 oz packs costing $6 in total, enter price 6, size 8, and packs 3. Entering the price of one pack alongside three packs would make the offer look three times cheaper than it is.

Choose a meaningful unit

Use weight for solid products, volume for liquids, and item count for comparable pieces. US fluid ounces measure volume; ordinary ounces measure weight. The calculator refuses to compare these families because a density assumption could change the answer.

A count comparison is only useful when the items perform the same job. One large trash bag is not equivalent to one small bag. Paper-towel rolls can contain different sheet counts and sheet areas. Concentrated detergent needs a cost-per-dose comparison based on the label.

What the number leaves out

This tool does not read store prices, verify coupons, or estimate your consumption. Enter the amount you actually expect to pay, including any costs you want to allocate to that item. If you may waste part of the larger pack, use the bulk calculator before treating the cheaper ounce as a saving.