Discount Calculator

Enter an original price and discount percentage to see the sale price and your savings — and add sales tax for the true final total.

Discount Calculator
Sale Price
You Save
Final Price (with tax)
Effective Discount
Original Price
Price Paid vs Amount Saved

How the Discount Calculator Works

A discount calculator answers two everyday questions instantly: what will I actually pay, and how much am I saving? It works for shoppers checking a sale, and for business owners setting promotions and confirming the margin impact of a markdown.

The Discount Formula

The sale price is Original Price × (1 − Discount% / 100). A $100 item at 25% off becomes $100 × 0.75 = $75, and you save $25. Add sales tax to the discounted price for the true out-the-door total: at an 8% tax rate, the $75 sale price becomes $81.

Stacking Discounts

Multiple discounts do not simply add together. Taking 20% off and then another 10% off is not 30% off — it is 0.80 × 0.90 = 0.72, or 28% off the original. Each discount applies to the already-reduced price, so stacked percentages are always a little less than their sum.

Tip: For sellers, remember a discount comes straight out of margin. A 25% price cut on a product with a 40% margin leaves only a 20% margin. Know your margin before advertising a sale so promotions stay profitable.

Discounts and Sales Tax

In most places, sales tax is charged on the discounted price, not the original — so a genuine discount lowers both the price and the tax you pay. This calculator applies tax after the discount to show the real total. Enter zero tax if you only want the pre-tax sale price and savings.

Frequently Asked Questions

How do I calculate a discount?
Multiply the original price by the discount percentage to find the savings, then subtract from the original price. A $100 item at 25% off saves $25, giving a $75 sale price. Or multiply the price by (1 minus the discount as a decimal).
How do I calculate the final price after a discount?
Subtract the discount from the original price, then add any sales tax on the discounted amount. A $100 item at 25% off is $75, and with 8% tax the final price is $81.
Do stacked discounts add up?
No. Successive discounts apply to the already-reduced price. Taking 20% off and then 10% off equals 28% off the original, not 30%, because the second discount is calculated on the lower price.
Is sales tax applied before or after a discount?
In most jurisdictions, sales tax is calculated on the discounted price, not the original. A real discount therefore reduces both the price and the tax owed. This calculator applies tax after the discount.
How do discounts affect profit margin?
A discount comes directly out of your margin. A 25% price cut on a product with a 40% margin leaves roughly a 20% margin. Always check your margin before setting a promotion so the sale remains profitable.

Related Calculators

Was this calculator helpful?
C
Written & reviewed by the CalcHeadquarters Editorial Team
Every calculator is built from published formulas and authoritative sources, then independently checked for accuracy before it goes live. Last updated June 2026. Read our editorial policy & methodology.