Discount Percentage Calculator

Multiply the price by the discount as a decimal to get the saving, or by one minus it to get the new price. Twenty percent off 100 leaves 80.

No. Twenty percent then ten percent is 28% off, not 30, because the second applies to the already-reduced price. The order does not matter — the two multiply.

Divide rather than adding the percentage back. A price of 80 after 20% off was 80 ÷ 0.8 = 100, not 80 × 1.2 = 96. It is the single most common discount error.

One minus the product of the remaining fractions. For 20% then 10%, that is 1 − (0.8 × 0.9) = 0.28, so 28%.

Only against the same starting price. A 50% discount off an inflated price can leave you paying more than a 20% discount off a fair one, which is why anchoring to an original price is such an effective sales tactic.

Convert the free item to a percentage of the total. Buy-one-get-one-free is a 50% discount on two units; buy three get one free is 25%.

Showing a higher original price so the discounted one seems better value. It is one of the most robust effects in consumer psychology, which is why struck-through prices are ubiquitous.

The rule of 100 is the common heuristic — below 100 units of currency, percentages read as larger; above, cash amounts do. Ten percent off 20 sounds better than 2 off; 50 off 500 sounds better than 10%.

Divide by one minus the discount. A sale price of 60 after 25% off was 60 ÷ 0.75 = 80.

An item sold at or below cost to attract customers who then buy profitable items. It is why milk and bread sit at the back of supermarkets.

Deep discounting trains customers to wait for sales, which shifts full-price demand into discount periods. Brands that discount predictably find their full-price weeks getting quieter.

It can. Price is used as a quality signal when other information is scarce, so a large permanent discount can reduce willingness to pay rather than increase sales.