Grocery Unit Price Calculator
Which pack gives you more for your money? Compare two grocery offers by weight, volume or item count, including multipacks.
Your result will appear here.
How to compare grocery prices
- Choose a currency and whether to compare by weight, volume or item count.
- For each offer, enter the price you will pay for the whole offer and the quantity in each pack.
- For a multipack, enter how many inner packs that price covers. For a single pack, leave this at 1.
- Select Compare offers to see both prices on the same quantity basis.
Total quantity = quantity per pack × number of packs
Unit price = total offer price ÷ total quantity
Percentage cheaper = (higher unit price − lower unit price) ÷ higher unit price × 100
Multipack or single pack?
Suppose Offer A is two 500 g packs for £3.50 in total. Offer B is one 750 g pack for £3.00. A costs £3.50 per kg, while B costs £4.00 per kg. Offer A has a 12.5% lower unit price, even though you pay more at checkout. These are illustrative prices, not live shop listings.
Compare the amount you can use
Choose products you would use in the same way. Compare drained weights with drained weights when that is the amount you will eat. For counted items, check that the pieces are a comparable size. A lower unit price may still cost you more overall if the larger pack spoils or goes unused.
Use the price you actually qualify for, including the full quantity required by a promotion. Currency selection changes the label only; this tool does not convert exchange rates or fetch prices. Both offers must use the same currency.
Comparing US and UK pack sizes
You can enter one offer in pounds or weight ounces and the other in grams or kilograms. The result puts both on the same weight basis. For liquids, choose US or Imperial fluid ounces to match the pack label. Use one currency for both prices; changing USD to GBP changes the label and does not exchange the money.
Units and calculation limits
Weight results show price per kg and per 100 g. Volume results show price per litre and per 100 ml. Count results show price per item. You can mix units within the same group, such as grams and pounds, but weight and volume cannot be compared without more information about the food.
One weight ounce is 28.349523125 g and one pound is 453.59237 g. A US fluid ounce is 29.5735295625 ml; an Imperial fluid ounce is 28.4130625 ml. Choose the fluid-ounce system written on the pack. Displayed figures are rounded; the comparison uses unrounded unit prices.
Common questions
What price should I enter for a multipack?
Enter the total price of the entire offer once. If three 200 g packs cost £4.50 altogether, enter price 4.50, quantity 200 g and number of packs 3. Do not enter 600 g as the quantity per pack as well.
Does the result include delivery or discounts?
Only amounts you enter are included. Use the final offer price after a discount. If a delivery charge applies equally to your whole basket, do not count it twice as a charge on each product.
Can I compare millilitres with grams?
No. This tool keeps weight, volume and item comparisons separate. The same volume can have a different weight for different foods.
Calculations run in your browser tab. This tool does not save your entries. Print a result to keep it. See our Privacy Policy for the website’s wider data practices.
Method and references
Each quantity is converted into grams, millilitres or items before dividing the offer price by that total. The percentage difference uses the higher unit price as its reference.