Discount Calculator
Instantly reveal the true value of any sale or promotion.
Enter any two values to calculate the third missing parameter.
Discount Calculator
Whether you're comparing sale prices, calculating how much you'll save, or setting a markdown price for your business, this discount calculator gives you the answer instantly.
How to Use This Calculator
- Find sale price: Enter original price and discount percentage → get discount amount and final price.
- Find discount %: Enter original price and sale price → get percentage saved.
- Find original price: Enter sale price and discount % → find what it was originally priced at.
Discount Formulas
Discount Amount = Original Price × Discount Rate
Sale Price = Original Price × (1 − Discount Rate)
Discount % = (Original Price − Sale Price) ÷ Original Price × 100
Original Price = Sale Price ÷ (1 − Discount Rate)
Example Calculations
Item: $120 | Discount: 25%
- Discount: $120 × 25% = $30
- Sale price: $120 − $30 = $90
Was $80, now $56 → Discount % = ($80 − $56) ÷ $80 = 30% off
Double Discounts (Stacked Discounts)
A 20% discount followed by an additional 10% discount is NOT 30% total. It's 20% + 10% of the remaining 80%:
$100 → 20% off = $80 → 10% off = $72. Total discount = 28%, not 30%.
Formula: Final = Original × (1 − d1) × (1 − d2) × ...
Common Mistakes to Avoid
- Adding stacked discounts — 20% + 10% ≠ 30%. Calculate sequentially as shown above.
- Forgetting tax on the discounted price — Sales tax applies to the final sale price, not the original. Calculate discount first, then add tax.
- Comparing discounts across different original prices — "50% off" on an overpriced item may be worse value than "20% off" on a fairly priced one. Always check the final price.
Frequently Asked Questions
What is a good discount percentage?
For retail, 10%–20% is a modest sale; 30%–50% is a significant promotion; 60%–70%+ typically signals clearance or end of line. From a business perspective, any discount that still exceeds your cost is profitable.
How do I calculate the original price from a sale price?
Divide the sale price by (1 − discount%). A $75 item after a 25% discount had an original price of $75 ÷ 0.75 = $100. Never multiply the sale price by the discount rate to find the original (common error).
How do discount codes work mathematically?
A percentage discount code applies the same formula. A flat dollar discount (e.g., "$10 off") simply subtracts $10 from the order total after other discounts are applied (in most cases).
Conclusion
This discount calculator handles every scenario — finding the sale price, figuring out how much you saved, or reverse-engineering the original price. Bookmark it for every shopping trip or pricing decision.
Related: Sales Tax Calculator | Margin Calculator | VAT Calculator | Tip Calculator
Money Hack
Don't forget to account for sales tax! Discounts are usually applied to the price *before* tax is calculated, meaning a discount actually saves you a little bit more in tax too.
