How to Use the Stacked Discount Calculator
"A 20% member discount plus an extra 10% coupon — that's 30% off, right?" Many people assume so, but it's wrong. Each discount applies to the remaining amount, not the original price, so the second discount is applied after the first one has already reduced the price.
The formula is: final price = original price × (1 − discount1/100) × (1 − discount2/100) × (1 − discount3/100). Applying 20% then 10% to a $100 item brings it to $72, meaning the true total discount is 28%, not 30%. Since it's multiplication, the final price is the same regardless of the order the discounts are applied.
Frequently Asked Questions
Each discount applies to the remaining amount, not the original price. 20% + 10% isn't 30% off — it's about 28% off. You must multiply, not add.
No. Multiplication is order-independent, so applying discounts in any order gives the same final price.
True discount rate (%) = (1 − final price ÷ original price) × 100.