🏷️ Discount Calculator
By ToolNimba Editorial Team · Updated 2026-06-19
This discount calculator turns a percent-off sale into real numbers. Enter the original price and the discount percentage, and you will instantly see the final price you pay and the amount you save. There is also an optional second discount field, so you can model stacked offers like an extra coupon on top of a sale and see what the deal truly comes to.
What is the Discount Calculator?
A discount is a reduction in price, almost always expressed as a percentage of the original price. The maths is short: the amount you save is the original price multiplied by the discount percent divided by 100, and the price you pay is whatever is left. So a 25% discount on a $100 item saves you $25 and leaves you paying $75. The percentage is the only lever, which is why a quick calculation can tell you in seconds whether a "huge" sale is actually a good deal.
The more interesting case is stacked discounts, where two offers apply to the same item, for example a 20% off sale plus an extra 10% coupon at checkout. A common mistake is to add the percentages and assume 30% off. Discounts almost always apply one after another, so the second one comes off the already-reduced price, not the original. Twenty percent off $100 is $80, and 10% off $80 is $72, which is a 28% effective discount rather than 30%. The order does not change the final price (multiplication is commutative), but stacking always saves you a little less than the two rates added together.
Knowing the effective discount helps you compare offers fairly. A single "30% off" beats "20% off plus 10% off", and "buy one get one half price" is really a 25% discount across the two items, not 50%. The calculator above does the arithmetic for you and, when you stack two discounts, spells out the true combined percentage so you are never fooled by clever signage.
When to use it
- Checking the final sale price of a clothing or electronics item before you reach the till.
- Working out whether a stacked coupon plus sale beats a single bigger discount elsewhere.
- Setting a markdown as a shop owner and confirming the price customers will actually pay.
How to use the Discount Calculator
- Enter the original price of the item.
- Enter the discount percentage, or tap one of the quick buttons.
- If two offers apply, enter the second discount percent in the optional field.
- Read off the price you pay and the amount you save, plus the true combined discount when stacking.
Formula & method
Worked examples
A $100 jacket marked 25% off.
- saved = 100 × 25 ÷ 100 = $25.00
- final = 100 − 25 = $75.00
Result: You pay $75.00 and save $25.00
An $80 pair of shoes at 20% off with an extra 10% coupon stacked on top.
- after first = 80 × (1 − 20 ÷ 100) = $64.00
- final = 64 × (1 − 10 ÷ 100) = $57.60
- saved = 80 − 57.60 = $22.40
- effective discount = 22.40 ÷ 80 × 100 = 28% (not 30%)
Result: You pay $57.60 and save $22.40, a 28% effective discount
Sale price and saving for common discounts on a $100 item
| Discount | You save | You pay |
|---|---|---|
| 10% off | $10.00 | $90.00 |
| 15% off | $15.00 | $85.00 |
| 20% off | $20.00 | $80.00 |
| 25% off | $25.00 | $75.00 |
| 33% off | $33.00 | $67.00 |
| 50% off | $50.00 | $50.00 |
| 70% off | $70.00 | $30.00 |
True combined discount when stacking two offers
| First discount | Second discount | Effective discount |
|---|---|---|
| 10% | 10% | 19% |
| 20% | 10% | 28% |
| 25% | 15% | 36.25% |
| 30% | 20% | 44% |
| 50% | 20% | 60% |
Common mistakes to avoid
- Adding stacked percentages together. A 20% sale plus a 10% coupon is not 30% off. The coupon comes off the already-reduced price, giving an effective 28%. Always multiply the remaining fractions rather than summing the rates.
- Confusing percent off with the price you pay. 40% off does not mean you pay 40% of the price. You pay the remaining 60%. The discount percent is what you save, not what you spend.
- Ignoring tax and fees. The discount applies to the listed price, but sales tax, shipping, or service fees are usually added afterward. The final amount on your receipt can be higher than the discounted price shown here.
Glossary
- Discount
- A reduction from the original price, normally stated as a percentage of that price.
- Original price
- The full price before any discount is applied. Also called the list price or sticker price.
- Sale price
- The price you actually pay after the discount, equal to the original price minus the amount saved.
- Stacked discount
- Two or more discounts applied to the same item in sequence, where each one reduces the running price further.
- Effective discount
- The single percentage that equals the total saving from stacked discounts, always less than the rates added together.
Frequently asked questions
How do I calculate a discount?
Multiply the original price by the discount percent and divide by 100 to get the amount saved, then subtract that from the price. For example, 25% off $80 saves $20, so you pay $60.
How do I work out the sale price?
Multiply the original price by (1 minus the discount as a decimal). A 30% discount means you pay 70% of the price, so a $50 item costs $50 × 0.70 = $35.
Is 20% off plus 10% off the same as 30% off?
No. Stacked discounts apply one after another, so the 10% comes off the already-reduced price. On $100 that is $72, an effective 28% off, slightly less than a straight 30%.
How do I calculate percent off a price?
Percent off is the discount rate applied to the original price. Divide the percent by 100, multiply by the price, and that is what you save. The rest is what you pay.
Does the order of two discounts change the final price?
No. Applying 20% then 10% gives the same result as 10% then 20%, because multiplication is commutative. The final price and total saving are identical either way.
How do I find the original price from a sale price?
Divide the sale price by (1 minus the discount as a decimal). If an item cost $75 after 25% off, the original was $75 ÷ 0.75 = $100.