How this discount calculator works
A discount is a reduction off an item's original price, usually quoted as a percentage. To find the amount you save, multiply the original price by the discount percentage divided by 100. To find what you actually pay, subtract that saving — or, in one step, multiply the original price by one minus the discount rate.
In formula form, final = original × (1 − discount/100) and savings = original − final. If you instead know both the original and the final price, you can work backwards to the percent off: percent off = (original − final) / original × 100.
Stacked discounts and sales tax
A second "extra" discount is applied to the already-reduced price, not added to the first. So 25% off followed by an extra 10% off means you pay 0.75 × 0.90 = 0.675 of the original — an effective 32.5% off, not 35%. Sales tax, when you add it, is applied after the discount, on the reduced price.
Quick reference: percent off on a $80 item
| Discount | You save | Final price |
|---|---|---|
| 10% off | $8.00 | $72.00 |
| 20% off | $16.00 | $64.00 |
| 25% off | $20.00 | $60.00 |
| 30% off | $24.00 | $56.00 |
| 50% off | $40.00 | $40.00 |
| 70% off | $56.00 | $24.00 |
Reference note: figures are rounded to cents for display. Final price and savings are computed from the exact amounts you enter.
Frequently asked questions
- How do I calculate a discount?
- Multiply the original price by the discount percentage divided by 100 to get the amount saved, then subtract it from the original price. In one step, final = original × (1 − discount/100). For example, $80 at 25% off is 80 × 0.75 = $60, saving $20.
- What is 20% off of $50?
- 20% of $50 is $10, so you save $10 and pay $40. Using the formula, 50 × (1 − 20/100) = 50 × 0.80 = $40.
- How do I find the percent off from two prices?
- Subtract the final price from the original price to get the saving, divide by the original price, then multiply by 100. An item marked down from $80 to $60 is (80 − 60) / 80 × 100 = 25% off.
- How do stacked discounts work?
- Stacked discounts apply one after another, not added together. A 25% discount then an extra 10% off gives 0.75 × 0.90 = 0.675, so you pay 67.5% of the original — an effective 32.5% off, not 35%.
- Is tax applied before or after the discount?
- Sales tax is normally applied after the discount, to the reduced price. So a $60 sale price with 8% tax becomes 60 × 1.08 = $64.80. This calculator adds any tax you enter on top of the discounted total.
- How much did I save?
- Your savings is the original price minus the discounted price. The calculator shows the dollars saved and the effective percent off, which combines any stacked discounts so you see the true total reduction.