Enter an original price and discount percentage to find the sale price — or find the discount rate from two prices.
When two percentage discounts apply one after another — say, an extra 10% off an already-marked-down item — they don't simply add up. Each discount applies to the price left over after the previous one, so a 20% discount followed by 10% off works out to a combined 28% off the original price, not 30%. This is a common source of confusion at checkout, and worth double-checking whenever "stacking" is advertised.
A percentage discount scales with price, so it saves more on expensive items. A flat dollar-amount discount saves the same no matter the price, making it relatively more valuable on cheaper items.
Stacked percentage discounts don't simply add together. A 20% discount followed by a further 10% off the reduced price results in a combined discount of 28%, not 30%, since the second discount applies to an already-reduced amount.
Some retailers set a higher "reference" price specifically to make a discount look larger than the item's typical selling price. Comparing to independent price history is a more reliable way to judge whether a deal is genuinely good.