Calculate stacked discounts, savings, quantity, sales tax, fees, and the final checkout total.
Calculator
Discount and Checkout Results
Review the main answer, supporting amounts, and calculation details.
Price, Savings, and Tax
Calculation Details
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How to calculate a discount
Enter the original unit price and the first discount. Add a second discount when a promotion applies another percentage to the already-discounted price. Quantity, estimated sales tax, shipping, and other fees then produce an estimated checkout total.
discounted unit price = original price x (1 - first discount) x (1 - second discount)
checkout total = discounted unit price x quantity + estimated tax + fees
Discount example with sales tax
Twenty percent off a $100 item saves $20 and leaves an $80 sale price. With 8.25% sales tax and no other fees, the estimated checkout total is $86.60.
How stacked discounts work
Successive discounts are multiplied, not added. A 20% discount followed by another 10% discount leaves 80% x 90% = 72% of the original price, so the effective discount is 28%, not 30%.
Quantity, tax, and fees
Savings and merchandise subtotal are multiplied by quantity. Estimated tax is applied to the discounted merchandise subtotal, then the entered shipping or fees are added. Actual taxability, rates, shipping treatment, exemptions, and marketplace fees depend on the location and transaction. Use the dedicated sales tax calculator to add tax, reverse tax from a total, or infer a rate. The IRS sales-tax calculator guidance notes that local rates can vary within a state, so use the rate shown for the actual purchase.
Compare the full offer
Check model, size, shipping, return policy, and conditions attached to a low advertised price. The FTC online-shopping guide recommends comparing item details and shipping fees, not only the headline price.
Frequently asked questions
How much is 25% off $80?
The savings are $20 and the discounted price is $60 before tax and fees.
Do I add two discounts together?
No. Apply the second percentage to the price remaining after the first discount.
Is sales tax charged before or after a discount?
This calculator applies the entered rate after discounts. Actual taxable amounts can differ by jurisdiction and promotion type.