Free unit price comparison calculator. Enter the price and size of each option (in grams, ounces, milliliters, liters and more) to find the price per unit and the best value for money.
Enter each option you are comparing: a label, the total price, the quantity (size), and the unit it is measured in. All options must use units from the same category (mass, volume, or count).
This tool compares the price-per-unit of several product options so you can tell which size or pack is the best value for money, not just the cheapest sticker price. For each option you enter the price and the quantity (size), plus the unit it is measured in. The calculator divides price by the quantity, converted to a shared base unit, to give a fair price-per-unit that works even when the packs use different units.
Units are grouped into three categories: mass (grams, kilograms, ounces, pounds), volume (milliliters, liters, fluid ounces, cups, pints, quarts, gallons), and count (each). Each unit is converted to its category's base unit (gram, milliliter, or each) using standard conversion factors, so a 12-ounce can at $3.99 and a 750-milliliter bottle at $5.49 can be compared on a like-for-like basis. All items in one comparison must belong to the same category, because a price per gram cannot be meaningfully compared with a price per milliliter.
The option with the lowest price-per-unit is flagged as the best value. Everything runs in your browser with no data sent anywhere, so it works offline and keeps your shopping list private. Bulk and family packs often win on price-per-unit, but not always after you factor in waste or perishability this tool cannot measure.
Frequently asked questions
How do I calculate price per unit?
Divide the total price by the total quantity in a common unit. For example, a 12-ounce pack at $3.99 costs 3.99 divided by 12 = about $0.33 per ounce. This tool does that for every option you enter and highlights the lowest price-per-unit as the best value.
Can I compare options measured in different units?
Yes, as long as they are in the same category. The tool converts ounces to grams, fluid ounces to milliliters, and so on, so a 12 oz can and a 750 ml bottle are compared on the same base unit. You cannot mix mass and volume (such as grams and milliliters) in one comparison, because there is no fixed conversion between weight and volume without knowing the product density.
Why is the cheapest option not always the best value?
The sticker price reflects the total cost, but value is about how much product you get for your money. A larger pack usually has a lower price-per-unit even though its total price is higher. The best-value flag points to the option that gives you the most product per dollar, which is usually the bulk size.
What unit should I use for items sold by count?
Use the count unit (each) for things sold as individual items, such as a 24-pack of rolls or a 6-pack of eggs. Enter the number of items as the quantity and select each, and the tool will compare the price per item across packs.
