per 100g vs per kg
Different label units can be misleading. The calculator converts them to the same basis before comparing.
Compare the real unit price, not the impression created by the packaging.
Different pack sizes, label units, multibuys and loyalty prices can be hard to compare. This tool converts them to the same basis first. Everything stays on this device: no sign-in and no upload.
£3.50 / 400g
vs
£5.20 / 750g
Step 1
Choose what you want to compare
Use the loyalty price when entered
For example Clubcard, Nectar or More Card. If no loyalty price is entered, the regular price is used.
Step 2
Enter product details
Compare between two and five products at a time.
Shopping notes
Common supermarket traps
A bigger pack is not always better value
A large pack can merely feel cheaper. Check the actual price per kg or per item.
Drained weight
For tins, olives and pickles, the stated weight may include liquid. Use drained weight where possible.
Loyalty price
Loyalty prices only apply if you have the relevant card or app. Untick the loyalty-price option when needed.
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Please note:This is not an official supermarket tool. Unit prices are for everyday shopping reference only. Check the latest shelf label, packaging, loyalty terms and offer details before buying.