Business
Discount calculator
Enter the original price and the percent off. Add a second discount if a coupon applies on top, and see why 20% plus 10% is not 30%.
What this means
- You pay $57.60 and save $22.40.
- 20% then 10% off is 28.00% in total, not 30%, because the second discount applies to the lower price.
- Sales tax, if any, is usually charged on the discounted price.
What if
About this calculator
What this calculator does
It applies one discount, then an optional second one to the already reduced price, the way stacked coupons usually work.
How it is calculated
price after = price * (1 - d1 / 100) * (1 - d2 / 100)
total discount = (price - price after) / price * 100
How to read the result
The final price is what you pay before tax. Total discount is the single percent that would give the same price.
Sources and method
Standard arithmetic with no outside data. The formula is shown under How it is calculated, and unit tests check worked examples, including edge cases.
This page uses arithmetic only, with no outside data.
Questions
Is 20% off plus 10% off the same as 30% off?
No. It is 28% off, because the 10% applies to the price after the first 20%.
Does the order of discounts matter?
No. Multiplying gives the same result in either order.
Is tax included?
No. Use the sales tax calculator on the final price.
How do I find the original price from a sale price?
Divide the sale price by (1 - discount / 100). $60 at 25% off came from $80.