Rechnerpilot Calculator
Price Comparison Calculator
Compare offers fairly: calculate the unit price per unit (kg, liter, piece), find the cheapest offer and see how much more the others cost in percent.
Available
Explanation
How Price Comparison Calculator works
Whether a 500-gram pack or a family size, a special offer or the standard shelf: offers can only be compared fairly if the price is related to the same unit. That is exactly what the unit price is – the price for one kilogram, one liter or one piece.
The calculator computes the unit price for each offer, sorts the cheapest to the top and shows for all others by how many percent they are more expensive. This makes it immediately clear which pack is really worth it and where a supposedly large pack just looks bigger.
Unit priceUnit price = price ÷ quantityThe package price is divided by the contained quantity in a fixed unit.
Extra cost in percentExtra cost % = (unit price − cheapest unit price) ÷ cheapest unit price × 100The surcharge is always related to the cheapest offer.
Knowledge
Unit price and unit of measure
The unit price makes offers with different package sizes comparable.
The unit price is the price for a fixed unit of measure – for example one kilogram, one liter or one piece. It is obtained by dividing the package price by the contained quantity.
- Fixed units are e.g. 1 kg, 1 l or 1 piece.
- Only offers in the same unit are comparable.
- The cheapest offer has the lowest unit price.
Practice
Practical examples
For illustration only – your own calculation is what counts.
Small or large pack?
Offer A costs €2.00 for 0.5 kg, offer B costs €3.00 for 1 kg. Per kilogram, B at €3.00 is cheaper than A at €4.00.
Result: B is the cheapest at €3.00/kg; A is about 33.3% more expensive.
- Mixed different units
One quantity is entered in grams, the other in kilograms – the unit prices are then not comparable.
Enter all quantities in the same unit, for example consistently in grams or consistently in liters.
- Only comparing the package price
Only the printed price is considered, without taking the contained quantity into account.
Always compare the unit price per unit – the package price alone says nothing about value for money.
- Quantity entered as 0
A quantity of 0 gives no meaningful unit price, because you cannot divide by 0.
Enter the quantity that is actually contained. The calculator flags a quantity of 0 as invalid.
FAQ
Frequently asked questions
What is the unit price?
The unit price is the price for exactly one unit, for example per kilogram, per liter or per piece. It is obtained by dividing the package price by the contained quantity, and makes offers with different package sizes directly comparable.
Must all offers use the same unit?
Yes. The calculator only compares the numerical values and does not convert units. Therefore enter all quantities in the same unit – for example all in grams or all in liters – otherwise the comparison is not meaningful.
Must the unit price be displayed in the store?
For most packaged goods, the German Price Indication Ordinance (PAngV) requires that the unit price per unit of measure be shown alongside the selling price. Even so, doing the math is worthwhile, because different reference quantities (100 g versus 1 kg) make the comparison on the shelf harder.
Is the large pack always cheaper?
Not necessarily. Promotional offers, smaller special packs or shrinkflation packs with less content at the same price can be more expensive than expected. Only the unit price per unit shows which offer is really the cheapest.
What does the extra cost in percent mean?
The extra cost indicates by how many percent the unit price of an offer is above the cheapest offer. The cheapest offer has 0%; a value of 33% means this unit is about a third more expensive.
- All offers must be given in the same unit. The calculator only compares numerical values and does not convert units.
- No automatic conversion between units (e.g. grams to kilograms) takes place.
- The comparison only evaluates the price per unit. Quality, brand, shelf life or need are not taken into account.
Sources
Sources and references
- Preisangabenverordnung (PAngV)Bundesministerium der Justiz
The German Price Indication Ordinance (PAngV) is the legal basis for the obligation to indicate the unit price per unit of measure alongside the selling price for many goods.
View sourceRetrieved: 08/24/2026 · Verified on: 08/24/2026 · Primary source - Grundpreis: So vergleichen Sie Preise richtigVerbraucherzentrale
Consumer information from the Verbraucherzentrale (German consumer advice center) on the unit price, shrinkflation and correctly comparing different package sizes.
View sourceRetrieved: 08/24/2026 · Verified on: 08/24/2026
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