Unit Price Comparison
Compare two products by unit price. Find which is cheaper per kg, litre, or item. Free.
How to use
Beat supermarket pricing tricks
Supermarkets sometimes change the size on offer just enough to make "per 100g" comparisons hard. A bigger pack isn't always cheaper per unit — shrinkflation has made multi-packs particularly suspect. Unit-price labelling is a legal requirement in UK shops, but always double-check the maths.
How to compare
For weight items, the calculator divides by quantity to give a price per kg or per 100g. For liquids, per litre or per 100ml. For multi-packs, choose "per item" and enter the number of items. Always compare like with like — including for promotion offers like "3 for £5".
Frequently asked questions
How do I compare two products by unit price?
Enter the price and quantity for each product. The tool divides price by quantity to show the cost per kg, litre or item, so you can see which is cheaper regardless of pack size.
Is the bigger pack always cheaper per unit?
Not always. Promotions and different pack formats can make a smaller pack better value, which is why checking the unit price helps.
Can I compare different units, such as grams and kilograms?
Use the same unit for both products or convert first so the comparison is fair.