Percentage Off / Sale Price Calculator
Calculate final sale price and dollar savings after any percentage discount.
Enter price and discount to see savings and total paid, with optional sales tax.
Percentage off calculations are used in retail, finance, and everyday budgeting. The core formula converts a discount percentage into an actual price reduction.
Sale price formula:
Sale Price = Original Price × (1 − Discount% / 100)
Discount amount formula:
Discount Amount = Original Price × (Discount% / 100)
Finding the discount percentage from prices:
Discount% = ((Original Price − Sale Price) / Original Price) × 100
Worked example 1 — Store discount:
Original price: $129.99. Discount: 35%.
Discount Amount = $129.99 × 0.35 = $45.50
Sale Price = $129.99 − $45.50 = $84.49
Worked example 2 — Reverse calculation:
Original: $200. Sale price: $155.
Discount% = ((200 − 155) / 200) × 100 = (45 / 200) × 100 = 22.5%
Stacked discounts:
When two discounts are applied sequentially, they do NOT simply add together.
Final Price = Original × (1 − D₁/100) × (1 − D₂/100)
Example: 20% off then an additional 10% off a $100 item.
= $100 × 0.80 × 0.90 = $72.00
Combined effective discount: 28% — not 30%.
With tax:
Final Price = Sale Price × (1 + Tax Rate / 100)
Example: $84.49 sale price + 8% tax:
= $84.49 × 1.08 = $91.25
Quick mental math tip: For 25% off: divide the price by 4. For 10% off: move the decimal left one place. For 15% off: take 10% and add half of that.