Discount Calculator
Calculate the final price after applying a discount percentage.
How discounts work
A discount reduces the original price by a fixed percentage. The calculation converts the percentage to a decimal and subtracts it from 1, giving the fraction of the original price you actually pay. Understanding this formula helps you evaluate deals and spot when a "discount" is less impressive than it appears.
Savings = Original price × Discount% ÷ 100
Final price = Original price × (1 − Discount% ÷ 100)
Example: $120 with 25% off
Savings = $120 × 0.25 = $30
Final price = $120 × 0.75 = $90Stacking discounts: they don’t add up the way you think
Two consecutive discounts are not the same as their sum. A 20% discount followed by a 10% discount is NOT a 30% discount — the second discount applies to the already-reduced price. This is important when evaluating stacked promotions, coupon codes, or wholesale-then-retail margins.
$100 with 20% off = $80
$80 with 10% off = $72 (saves $28, not $30)
Effective discount = 28% (not 20% + 10% = 30%)
Formula for combined discount:
Combined% = 100 − (100 − D1%) × (100 − D2%) ÷ 100Common discount table: what you pay
| Discount | You pay | Save on $100 | Markup needed to break even |
|---|---|---|---|
| 10% off | 90% | $10 | 11.1% |
| 15% off | 85% | $15 | 17.6% |
| 20% off | 80% | $20 | 25% |
| 25% off | 75% | $25 | 33.3% |
| 30% off | 70% | $30 | 42.9% |
| 40% off | 60% | $40 | 66.7% |
| 50% off | 50% | $50 | 100% |
| 70% off | 30% | $70 | 233% |
Tips for smart shoppers
- Compare final prices, not discount percentages. A 40%-off $90 item ($54) may cost more than a 10%-off $45 item ($40.50). Percentages without the original price are meaningless.
- Watch for inflated "original" prices. Some retailers raise the listed price before a sale to make the discount appear larger. Check the item's price history using tools like CamelCamelCamel (Amazon) or browser extensions that track price history.
- Factor in total cost. A 20% discount wiped out by expensive shipping or a required minimum purchase may be a worse deal than a slightly higher price with free delivery.
- The break-even markup is always higher than the discount. A 25% discount requires a 33.3% markup just to return to the original price. This is essential knowledge for business pricing decisions.
Frequently asked questions
How do I calculate a discount?
Multiply the original price by the discount percentage to get the saving, then subtract it. For 30% off 80: 80 × 0.30 = 24 saved, so you pay 56.
How do I work out the percentage off from two prices?
Divide the saving by the original price and multiply by 100. If an item drops from 80 to 56, that is (24 ÷ 80) × 100 = 30% off.
How do stacked discounts work?
They apply one after another, not added together. 20% then 10% off 100 is 100 → 80 → 72, an effective 28% discount, not 30%.
Does this include sales tax?
No. It calculates the discount on the listed price. Any sales tax or VAT is applied separately, usually after the discount.
Calculates the final price after applying a percentage discount to the original price. Shows both the amount you save and the final price you pay.
Final price = Original × (1 − discount%/100) You save = Original × discount%/100