How to calculate a discount: quick answer
To calculate a discount, multiply the original price by the discount percentage as a decimal. Then subtract the discount amount from the original price to get the sale price. For example, 20% off $80 is $16 in savings, so the sale price is $64. You can also use ToolAlto’s Discount Calculator for a quick result.
What is a discount?
A discount reduces an original price by a stated percentage. For example, a 20% discount means the customer pays 80% of the original price.
Enter an original price and discount percentage to see the savings and sale price instantly.
Open Discount Calculator →How to calculate the discount amount
Multiply the original price by the discount percentage expressed as a decimal.
Discount amount = Original price × (Discount percentage ÷ 100)
Example: for a $80 item with a 20% discount, the savings are $80 × 0.20 = $16.
How to calculate the final sale price
Subtract the discount amount from the original price.
Sale price = Original price − Discount amount
Using the $80 example, the sale price is $80 − $16 = $64.
You can also calculate it directly as Original price × (1 − Discount percentage ÷ 100).
How to calculate a discount quickly
- Write down the original price.
- Write down the discount percentage.
- Calculate the percentage amount.
- Subtract the savings from the original price.
- Check the final price against the advertised discount.
For a quick calculation, use ToolAlto's Discount Calculator. It shows both the amount saved and the final sale price.
Common discount examples
- 10% off $50: save $5, pay $45.
- 25% off $120: save $30, pay $90.
- 30% off $200: save $60, pay $140.
- 50% off $75: save $37.50, pay $37.50.
How to find the original price after a discount
If you know the sale price and the discount percentage but need to work backward to the original price, divide the sale price by 1 minus the discount rate.
Original price = Sale price ÷ (1 − Discount percentage ÷ 100)
For example, if an item costs $64 after a 20% discount, the original price is $64 ÷ 0.80 = $80. This is different from simply adding 20% to the sale price.
Discount vs. percentage change
A discount starts with an original price and calculates a reduced price. Percentage change compares an old value with a new value. The formulas can look similar, but the question being answered is different.
For broader percentage formulas and percentage-change examples, read How to Calculate a Percentage.
What if there are two discounts?
Two discounts applied one after another are usually calculated sequentially rather than simply added together. For example, a 20% discount followed by another 10% discount leaves 72% of the original price: 0.80 × 0.90 = 0.72. That is a total reduction of 28%, not 30%.
Discounts, taxes, and fees
A discounted price is not always the final amount you pay. A store, service, or checkout page may apply taxes, shipping, fees, or other charges afterward. The Discount Calculator focuses on the original price, discount percentage, savings, and resulting sale price before those additional amounts.
Common mistakes
- Subtracting the percentage number itself instead of calculating its value.
- Using the discounted price as the starting price for the first discount.
- Adding multiple percentage discounts when they are applied sequentially.
- Rounding the discount too early.
- Assuming a discount calculation includes taxes or other checkout charges.
FAQ
How do I calculate 20% off a price?
Multiply the original price by 0.20 to find the savings, then subtract the savings from the original price. For example, 20% off $80 saves $16 and gives a sale price of $64.
What is the formula for sale price?
Sale price = Original price × (1 − Discount percentage ÷ 100).
How do I calculate how much I save?
Multiply the original price by the discount percentage divided by 100.
Can I calculate discounts without a calculator?
Yes. Common percentages such as 10%, 25%, and 50% can often be found mentally, but a calculator is useful for less familiar percentages or decimal prices.
Is a discount the same as percentage decrease?
A discount is a specific kind of reduction in price. Percentage decrease is a broader way to describe a reduction from an original value.