Discount Calculator · Practical guide
How to Calculate Stacked Discounts
30% off plus an extra 20% off is not 50% off — here is the sequence math that stores hope you skip.
At a glance
Stacked Discounts Multiply, They Do Not Add
When a store offers 30% off plus an extra 20% off, the second discount applies to the already-reduced price. Each discount multiplies what remains, so the combined saving is always less than the sum of the percentages. For 30% + 20%, the real discount is 44%, not 50%.
Interactive tool
Discount Calculator
Enter your own values, then compare the result with the examples below.
Discount Result
Worked Example: $100 Item
Step one: 30% off $100 leaves $70. Step two: the extra 20% comes off $70, which is $14, leaving $56.00. You saved $44 total — 44% — not the $50 you would save with a true 50% markdown. Run each step through the calculator above: enter $100 with 30% off, then enter the $70 result with 20% off.
Common Stacked Combinations
| Stacked Discounts | You Pay | Effective Discount |
|---|---|---|
| 20% + 10% | 72% of original | 28% |
| 30% + 20% | 56% of original | 44% |
| 40% + 25% | 45% of original | 55% |
| 50% + 50% | 25% of original | 75% |
The General Formula
Final price = original × (1 − d1) × (1 − d2), where d1 and d2 are decimals. The effective discount is 1 − (1 − d1)(1 − d2). Order does not matter for the final price — 30% then 20% equals 20% then 30% — but the dollar value of each step differs, which matters if one discount is a fixed coupon applied first or last.
Frequently Asked Questions
Is 30% off plus 20% off the same as 50% off?
No. Stacked, they give 44% off: you pay 70% × 80% = 56% of the original price. A single 50% discount would leave you paying 50%.
Does the order of stacked discounts matter?
For two percentage discounts, no — multiplication is commutative, so the final price is identical either way. If a fixed-dollar coupon is involved, the order can change the total.
How do I calculate three stacked discounts?
Keep multiplying: final = original × (1 − d1) × (1 − d2) × (1 − d3). For 25% + 20% + 10% on $200, that is $200 × 0.75 × 0.80 × 0.90 = $108.
Why do stores stack discounts instead of one big sale?
Because 40% + 25% sounds bigger than the 55% it actually delivers. The stacked framing lifts perceived value while the store keeps a higher final price.