Discount Calculator
Calculate any sale price instantly — including stacked discounts and tax.
Sale Price
$56.00
You save $24.00 (30% off)
Original Price
$80.00
Discount
30% off
Amount Saved
$24.00
The tag says the sale price. You know the discount percentage. What was the original price?
Original Price
$60.00
You saved $18.00 (30% off)
Original Price
$60.00
Discount
30% off
Amount Saved
$18.00
Note: Stacked discounts are applied sequentially, not added. 20% then 10% ≠ 30% off.
Final Price
$72.00
You save $28.00
Total Effective Discount
28%
Equivalent Single Discount
28%
Buy X items, get a discount on additional items. Calculates your effective per-unit price.
Total You Pay
$50.00
You save $50.00
Effective Per Unit
$25.00
Total Without Deal
$100.00
Effective Discount
50%
How Stacked Discounts Work
A "stacked" or sequential discount applies each percentage to the already-reduced price — not to the original. This is why 20% off then 10% off does not equal 30% off.
The math
Starting price: $100. First discount: 20% off → $80. Second discount: 10% off $80 → $72. Total discount: $28 = 28%, not 30%.
The equivalent single discount formula for N stacked discounts is:
effective = 1 − (1 − d1)(1 − d2)(1 − d3)...
e.g. 1 − (1 − 0.20)(1 − 0.10) = 1 − (0.80 × 0.90) = 1 − 0.72 = 0.28 = 28%
e.g. 1 − (1 − 0.20)(1 − 0.10) = 1 − (0.80 × 0.90) = 1 − 0.72 = 0.28 = 28%
Quick Reference: Sale Price at Common Discounts
| Original | 10% off | 15% off | 20% off | 25% off | 30% off | 50% off |
|---|
Frequently Asked Questions
-
Sale Price = Original Price × (1 − Discount% ÷ 100). For example, 30% off $80: $80 × 0.70 = $56.00. You save $24.00.
-
No. Stacked discounts are applied sequentially, not added. 20% off then 10% off = 28% effective discount, not 30%. The second discount applies to the already-reduced price. Use the Stacked Discounts mode to see every step.
-
Original Price = Sale Price ÷ (1 − Discount%). Switch to "Find Original" tab above. Example: shirt costs $42 after 30% off → $42 ÷ 0.70 = $60.00 original.
-
Tax is applied to the sale price (after discount), not the original price. Use "Add tax" toggle in Simple mode. Final = Sale Price × (1 + Tax% ÷ 100). $56 with 8% tax = $56 × 1.08 = $60.48.
-
30% off $80 = $56.00. You save $24.00. Formula: $80 × (1 − 0.30) = $80 × 0.70 = $56.00.