Discount Calculator
Enter the original price and discount percentage to instantly see how much you save and what the final sale price is — with an optional sales tax applied after the discount.
How the Discount formula works
Discount math in three steps:
Savings = Original price × (Discount% / 100) Sale price = Original price − Savings Final total (with tax) = Sale price × (1 + Tax% / 100)
Step-by-step calculation
- Multiply the original price by the discount percentage to find the savings amount.
- Subtract the savings from the original price to get the sale price.
- If sales tax applies, multiply the sale price by (1 + tax rate) to get the final total — tax is calculated after the discount, matching how most retailers apply it.
Worked example
A $120 jacket at 25% off, with 8% sales tax: Savings = 120 × 0.25 = $30. Sale price = 120 − 30 = $90. Final total = 90 × 1.08 = $97.20.
Frequently asked questions
Is sales tax calculated before or after the discount?
In most jurisdictions, sales tax is applied to the discounted (sale) price, not the original price — which is what this calculator does by default.
How do I calculate stacked discounts, like 20% off plus an extra 10%?
Stacked percentage discounts multiply rather than add. 20% off followed by 10% off is not 30% off — it's equivalent to paying 80% × 90% = 72% of the original price, an effective discount of 28%.
How do I find the original price if I only know the sale price?
Divide the sale price by (1 − discount as a decimal). For example, a $90 sale price after a 25% discount means the original price was 90 / 0.75 = $120.