Discount Calculator
Find the final sale price after one or more percentage discounts. Handles stacked discounts and shows the effective combined discount.
How to use the Discount Calculator
- Enter your inputs into the Discount Calculator above.
- Results update instantly as you type — no submit button needed.
- Adjust any value to see how the result changes in real time.
The discount formula
Final = Original × (1 − d1) × (1 − d2) × … · · · Combined discount = 1 − (Final / Original)
Stacked discounts are multiplicative, not additive. A 20% off + 10% off does NOT equal 30% off — it equals (1 − 0.20)(1 − 0.10) = 0.72, or 28% combined off.
Worked example
A $150 item at 25% off then an additional 15% off at checkout: 150 × 0.75 × 0.85 = $95.63. Combined effective discount: 36.25%, not the 40% you'd get by adding the percentages.
Frequently asked questions
Why don't discounts simply add?
Because the second discount applies to the already-discounted price, not the original. The savings on the second pass are smaller in dollar terms.
How do I find the original price from a sale price?
Divide the sale price by (1 − discount). A $60 item at 25% off had an original price of 60 / 0.75 = $80.
Are coupons applied before or after sale prices?
Varies by retailer. Most apply the percentage-off coupon after the sale price; flat-dollar coupons can apply either way. Check the small print.