Shopping calculations
How to calculate discount
Multiply the original price by the discount rate to find the amount saved, then subtract that amount from the original price.
Open the discount calculatorDiscount = original price × (discount percentage ÷ 100)
Final price = original price − discount
A simple worked example
An item costs $80 and is 25% off.
- Convert 25% to 0.25.
- Multiply $80 × 0.25 = $20 discount.
- Subtract $80 − $20 = $60 final price.
You can calculate the final price directly with the amount you keep: $80 × (1 − 0.25) = $80 × 0.75 = $60.
Find the discount percentage
If you know the original and sale prices, first find the amount saved. Then divide by the original price:
Discount percentage = (original price − sale price) ÷ original price × 100
A product reduced from $120 to $90 saves $30. The discount is $30 ÷ $120 × 100 = 25%. Dividing by the sale price instead is a common mistake.
Reverse a discount to find the original price
If $72 is the price after a 20% discount, it represents 80% of the original. Divide by 0.80:
Original price = $72 ÷ (1 − 0.20) = $90.
This is why adding 20% to the sale price does not undo a 20% discount. Twenty percent of $72 is smaller than 20% of $90.
Multiple discounts are applied in sequence
| Step | Calculation on $100 | Price |
|---|---|---|
| 20% off | $100 × 0.80 | $80 |
| Then 10% off | $80 × 0.90 | $72 |
The combined reduction is 28%, not 30%. Multiply the remaining-price factors: 0.80 × 0.90 = 0.72, so 72% remains.
Taxes, shipping, minimum-spend rules and excluded items can change the checkout total. Confirm whether tax is calculated before or after a discount in the relevant jurisdiction.
Check a sale price with ToolPixels
The free Discount Calculator returns the discount amount and final price from an original price and percentage. Keep all values in one currency and round currency only at the final step.