Discount Calculator
Find the final price after a discount, stack multiple coupons, and see exactly how much you actually save (hint: it's rarely what the sticker says).
Your numbers
Stacked discounts apply sequentially (e.g. 20% off, then extra 10% off the discounted price).
Result
Final Price
$80.00
The trick with stacked discounts
Two discounts almost never add up to their face values. The classic example: a store offers 30% off, and you also have a 20% off coupon. Your instinct says 50% off — your final price says otherwise:
Original: $100.00 After 30% off: $70.00 (−$30) After extra 20% off: $56.00 (−$14) Total saved: $44.00 (44%, not 50%)
This is because the second discount applies to the already-reduced price, not the original. The order doesn't matter for percentage-only stacking — 30% then 20% gives the same result as 20% then 30%. But it does matter when one of the discounts is a flat dollar amount.
When order matters
If you have a flat $10 off coupon and a 20% off sale, the order changes the math:
- $10 first, then 20% off: ($100 − $10) × 0.80 = $72.00
- 20% off first, then $10: ($100 × 0.80) − $10 = $70.00
As a shopper, ask for the flat amount to be applied after the percentage discount — you save more. As a retailer, do the opposite to preserve margin.
Formula
Sale Price = Original Price × (1 − Discount % / 100) For stacked percentages: Effective Discount = 1 − (1 − d1)(1 − d2)(1 − d3)…
Frequently asked questions
How do stacked discounts work?▼
Stacked discounts apply one after another, each to the already-discounted price. 20% off + extra 10% off is NOT 30% off — it's actually 28% off, because the second 10% applies to the reduced price, not the original.
What's a 'percentage off' vs 'amount off'?▼
Percentage off scales with price (15% off saves more on expensive items). Amount off is a flat dollar reduction (a $10 off coupon saves $10 whether the item is $20 or $200). Stores often combine both — flat off, then percent off.
How do I calculate the sale price from a percentage discount?▼
Sale Price = Original Price × (1 − Discount % / 100). For a 25% discount on $80: $80 × 0.75 = $60. The savings are $80 − $60 = $20.
Are discounts applied before or after tax?▼
Almost always before tax — the discount reduces the taxable amount. So a $100 item with 20% discount and 8% sales tax becomes ($100 × 0.80) × 1.08 = $86.40, not $92.