Discount Calculator
Discount calculator: final sale price and savings after a percent-off discount, with optional sales tax.
Editorial review: Farrow (pseudonym; identity and professional credentials are not disclosed). This page is for educational purposes, not professional advice.
Your inputs
Results update as you type. Nothing you enter leaves your device.
Results
- You save
- $30.00
- Price before tax
- $90.00
Example with the starting values
These results use the calculator's initial inputs. Change the values above to calculate your own estimate.
Inputs
- Original price
- 120 $
- Discount
- 25 %
- Sales tax
- 0 %
Results
- Final price
- $90.00
- You save
- $30.00
- Price before tax
- $90.00
How does the Discount Calculator work?
A discount is a reduction from an item's original price, usually stated as a percent off. The sale price is Original × (1 − discount / 100), and the amount saved is Original × discount / 100.
Sales tax is then applied to the discounted price, Final = Sale × (1 + tax / 100), which is how US retailers charge it. For example, $120 at 25% off is $90, and with 8% tax you pay $97.20.
Frequently asked questions
How do I calculate a percent off?
Multiply the price by the discount as a decimal and subtract it. For 30% off $80, the savings are 80 × 0.30 = $24, so the sale price is $56.
How do I calculate 20% off and then an extra 10% off?
Apply the discounts one after the other, not added together. $100 at 20% off is $80, then 10% off is $72, a total discount of 28%, not 30%.
How do I find the original price from a sale price?
Divide the sale price by (1 − discount). If an item costs $60 after 25% off, the original price was 60 / 0.75 = $80.
Is sales tax charged on the original or the sale price?
In most states, sales tax applies to the discounted price you actually pay.
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