A percentage discount can make an offer look attractive, but the important question is the final price and whether you are comparing like-for-like products. A simple formula tells you the price after a discount.
Formula for a discounted price
Discount amount = original price × discount percentage ÷ 100. Subtract the discount amount from the original price. At €80 with a 25% discount, you save €20 and pay €60.
The discount calculator handles the calculation. Use the percentage calculator for a price change or saving, and the unit price calculator to compare different package sizes.
Why unit price matters
A lower total price does not always mean that a product is cheaper per kilogram or litre. Divide the price by the quantity and compare the same unit. The German consumer advice centre explains unit-price labels, which help shoppers compare different pack sizes.
Example: two package sizes
A 500 g pack costs €2.50, while a 750 g pack costs €3.45. The smaller pack costs €5.00 per kilogram; the larger pack costs €4.60 per kilogram. The larger pack costs more overall but less per kilogram – provided you need the extra amount and it will not go to waste.
Check these points before buying
- Is the original price for the same product and quantity?
- What is the final price after the discount?
- What is the price per kilogram, litre or item?
- Will you actually use the larger quantity?
Prices above are examples. Check offers, promotional terms and reference prices with the retailer.
Check unit prices as well as discounts
A large percentage discount does not automatically make a product cheap. Compare the final price and, for groceries, cleaning products or toiletries, the unit price per kilogram, litre or item. Also consider pack size, delivery charges and the conditions attached to a promotional price. A smaller pack or an inflated previous price can make an advertised discount less attractive than it looks.
How do you calculate the final price?
Subtract the discount amount from the original price. At 20% off, you pay 80% of the original price. Use a calculator to compare offers with different unit prices.