Discount Calculator
A 30% discount followed by an extra 20% off is not 50% off. Stacked discounts apply to the reduced price each time, and this shows the real combined rate alongside the final figure.
Price & Discounts
Set a discount to 0 to skip it. Discounts apply in order, top to bottom.
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Why stacked discounts fall short of the sum
Each discount applies to whatever the price has already become. Take 30% off $240 and you are at $168. The extra 20% comes off $168, not $240, so it removes $33.60 rather than $48. The final price is $134.40 — a true discount of 44%, not the 50% the signs imply.
The shortfall grows as the discounts grow. Two 50% discounts give 75% off,
never 100%. The general rule: multiply the remaining fractions.
1 − (1 − d₁)(1 − d₂) is the true
combined rate.
Order matters when a flat coupon is involved
Percentages commute — 30% then 20% gives the same result as 20% then 30%. A fixed-dollar coupon does not. A $20 coupon applied before a 30% discount is worth only $14 to you, because the discount then removes 30% of the reduced total. Applied after, it is worth the full $20. Retailers almost always apply percentages first, which is the order used here.
Tax is charged on what you actually pay
In nearly all jurisdictions, sales tax or VAT applies to the discounted price, not the original. Manufacturer rebates are the usual exception: because the retailer still receives full price, tax is often charged on the pre-rebate amount.