How to compare unit prices
Unit price = price ÷ size (in the same unit)
Example
Rice at 3.50 for 500 g is 7.00 per kg. A 1 kg bag at 5.80 is 5.80 per kg, so the big bag is 17% cheaper.
Splitting a bill instead? Try the bill splitter, or work out a sale price with the discount calculator.
Frequently asked questions
What is a unit price?
The price for the same amount of each product, such as per kilogram, per litre or per item. It shows which pack is really cheaper, whatever its size.
Can I compare grams with ounces, or litres with millilitres?
Yes. Sizes are converted, so you can compare a 500 g pack with a 1 lb bag, or a 2 L bottle with 12 cans of 330 ml. Weights can't be compared with volumes, though.
Is the bigger pack always cheaper?
Often, but not always: special offers on smaller packs can beat the big ones. It's only a saving if you'll use it all before it goes off.