Unit Price Calculator - Compare Price per kg, Litre or Piece
Compare unit prices
| Item | Price | Quantity | Unit | Items in pack | |
|---|---|---|---|---|---|
Brand B is the cheapest at 4.29 per kg.
| Item | Unit price | vs cheapest |
|---|---|---|
| Brand A | 4.98 / kg | +16.1% |
| Brand B | 4.29 / kg | — |
| Brand C | 5.32 / kg | +24.0% |
Prices are compared per kilogram, litre or piece in whatever currency you type. Pack size multiplies the quantity.
How to compare unit prices
Shelf prices are designed to be hard to compare: 500 g at 2.49 against 1 kg at 4.29, or a six-pack of 330 ml cans against a two-litre bottle. The only fair comparison is the price per unit of what you actually get — per kilogram, per litre, per piece. This calculator does that conversion for any mix of grams, ounces, millilitres and fluid ounces and ranks the options.
Steps
- 1 Enter each option with its shelf price, the quantity on the label and the unit it is sold in.
- 2 For multipacks, enter the size of one item and how many items are in the pack — the calculator multiplies them.
- 3 Read the unit price of each option and the percentage it costs more than the cheapest one.
Weight, volume and count
Grams, kilograms, ounces and pounds are weights; millilitres, litres, fluid ounces, cups, pints, quarts and gallons are volumes; pieces are a count. Items in different groups cannot be compared without knowing the density of the product, so the calculator compares only within one group and tells you if a row does not belong. Pick the group that matches the label — most food is sold by weight, drinks by volume, eggs and tablets by count.
Why unit price beats the shelf price
Larger packs are usually cheaper per unit, but not always: promotions on the small size, or a large size priced for convenience, flip the result often enough that checking is worth the ten seconds. Supermarkets in many countries must print the unit price on the shelf label; where they do, it is often in tiny type and in inconsistent units — per 100 g on one product, per kg on the next. This calculator puts every option on the same footing.
Multipacks and bulk
A multipack lists the size of one item and the number of items. Enter both and the calculator uses the total quantity. Bulk sizes are cheaper per unit only if you use them before they spoil or lose quality — a lower unit price on a product you throw a third of away is a higher price in practice.
Ounces and fluid ounces
An ounce (oz) is a weight of 28.35 g; a fluid ounce (fl oz) is a volume of 29.57 ml. They are not interchangeable and the calculator treats them as different groups. US and UK fluid ounces also differ slightly; the calculator uses the US fluid ounce, cup, pint, quart and gallon.