Discount Calculator
Find the sale price and money saved from a percentage discount, including stacked offers.
What the Discount Calculator does
A discount multiplies the price by (1 − rate). Stacked discounts multiply in sequence rather than adding: 20% off then a further 20% off leaves 64% of the original price, a 36% saving, not 40%.
Formula
Sale price = Original × (1 − Discount)Stacked = Original × (1 − D₁) × (1 − D₂)Savings = Original − Sale price
Inputs explained
| Input | Unit | Required | Notes |
|---|---|---|---|
| Original price | selected currency | Yes | Accepts more than 0. |
| Discount | % | Yes | — |
| Additional discount | % | Optional | Applied after the first, as most stacked offers work. |
| Sales tax | % | Optional | — |
| Currency | one of 10 options | Optional | — |
How to use it
- Choose Currency.
- Enter Original price and Discount.
- Optionally add Additional discount and Sales tax.
- Select Calculate.
Worked example
A $120 jacket at 30% off, with an extra 10% coupon.
- Price
- 120
- Discount
- 30
- Additional
- 10
$120 → $84 → $75.60. You save $44.40, an effective 37% discount rather than 40%.
Frequently asked questions
Does 50% off plus 20% off equal 70% off?
No. It leaves 0.5 × 0.8 = 40% of the price, which is a 60% discount. Stacked percentages never add.
Is tax applied before or after the discount?
After. Sales tax is charged on the amount you actually pay, which is why this calculator applies it to the discounted price.