Unit Price & Better Deal Calculator

The unit price is what one unit of a product costs: per kilogram, per liter, per piece. Comparing unit prices is how to tell which of two packs is the better deal, and the best value for money, when their sizes differ.

Unit price = Price / Quantity

Enter each item's price and quantity, and this price comparison calculator shows both unit prices and which item is cheaper per unit.

How to compare two items

Enter both quantities in the same unit. The calculator divides the price by whatever number you give it, so 750 g and 1.2 kg must both be in grams (750 and 1,200) or both in kilograms (0.75 and 1.2). The unit prices are then per gram or per kilogram.

Example: is the bigger pack cheaper?

Coffee comes in a 750 g bag for $8.99 and a 1.2 kg bag for $15.49. In kilograms:

1. Small bag: the price divided by 0.75 kg.

   8.99 / 0.75 = 11.99 $/kg

2. Large bag: the price divided by 1.2 kg.

   15.49 / 1.2 = 12.91 $/kg

Here the small bag is the better deal, by 12.91 − 11.99 = $0.92 per kilogram. Bigger packs are often cheaper per unit, but not always.

Example: a multipack and a bottle

A 12-pack of 355 mL cans costs $5.49, and a 2 L bottle $2.29. First turn the cans into liters: 12 × 0.355 = 4.26 L.

1. Cans: 5.49 / 4.26 = 1.29 $/L
2. Bottle: 2.29 / 2 = 1.15 $/L

The bottle is cheaper per liter.

Tips

• Use the price you will actually pay, after any discount or multi-buy offer that you will really use.
• Shelf labels don't always use the same unit: one may show the price per 100 g and the next per kg. A price per 100 g times 10 is the price per kg.
• The cheapest per unit is only a saving if you use it all. A bulk pack that goes off before it's finished can cost more in the end.

Frequently asked questions

Is buying in bulk always cheaper?

No. Larger packs are often cheaper per unit, but not always, especially when the smaller one is on offer. The coffee example above is one where the large bag costs more per kilogram.

Can I compare different units, such as ounces and grams?

Convert one first, so both are in the same unit: 1 oz is 28.35 g, and 1 lb is 453.6 g. The Mass Converter and Volume Converter do this for any unit.