Discount amount, final price, and tax
A discount is calculated from the original price. Multiply the original price by the discount percentage expressed as a decimal to find the savings, then subtract the savings from the original price to get the discounted price. If you provide a tax rate, tax is then applied according to the calculator’s selected inputs.
Worked example
An item marked $80 off by 15% has a discount of $12, leaving a pre-tax price of $68. A tax rate applied to the discounted price would be calculated from $68, not the original $80. Store offers can have exclusions or different rules, so compare the result with the terms of the actual promotion and receipt.
A percentage discount is not the same as a dollar-off discount, and stacking discounts generally means applying each discount to the already-reduced amount unless the offer states otherwise.
Tips for accurate results
Enter the original price and the percentage off to get the sale price and the amount saved. For a stacked offer such as 20% off and an extra 10% off, apply them one after another: the combined discount is 28%, not 30%. Calculate sales tax on the discounted price unless the store says otherwise.
Common mistakes and limits
A big percentage is not always a good deal. Check that the original price was a real price, and compare the sale price per unit with alternatives. Also consider whether a discount encourages you to buy something you did not plan to buy; saving 40% on something unnecessary is still spending.
Learn more: Percentages in everyday life.