Quick answer
Sale price = original price × (1 − discount ÷ 100). A $80 item at 25% off sells for $60, saving $20.
Enter the original price and the percentage off. The calculator returns the sale price and the amount saved.
Related tools: Percent Error Calculator: Compare a measured value with the true value. Decimal to Percent Calculator: Convert a decimal to a percentage. Percent Increase Calculator: Percentage increase between two values.
How to use the Percent Off Calculator
- Enter original price (0 or more).
- Enter discount (%) (between 0 and 100).
- Press Calculate to see the result, and use Reset to start again.
| Input | What to enter | Allowed values |
|---|---|---|
| Original price | A number | ≥ 0 |
| Discount | A number, in % | ≥ 0, ≤ 100 |
Formula and method
Formula
sale price = price × (1 − discount ÷ 100)
IEEE-754 double precision; shown to at most 6 decimal places.
The discount amount is price × percent ÷ 100; subtract it from the price.
Worked examples
These examples are verified: each one is an automated test case that the live calculator must reproduce exactly.
Example 1
Inputs: Original price = 80; Discount = 25.
| Result | Value |
|---|---|
| Sale price | 60 |
| You save | 20 |
Example 2
Inputs: Original price = 19.99; Discount = 10.
| Result | Value |
|---|---|
| Sale price | 17.991 |
| You save | 1.999 |
The first line is the headline result (sale price). Below it the percent Off Calculator lists you save, which describe the same case from other angles. IEEE-754 double precision; shown to at most 6 decimal places.
Stacked discounts
Two discounts do not add. Take 20% off and then another 10% on $100: 100 × 0.80 × 0.90 = $72, a 28% total discount, not 30%. Apply them one after the other.
Working backwards
If you know the sale price and the original, the discount is (original − sale) ÷ original × 100. If you know only the sale price and the percentage off, the original is sale ÷ (1 − discount ÷ 100): $60 at 25% off came from 60 ÷ 0.75 = $80.
How the result changes with original price
Holding every other input at the first worked example, this table changes only original price. It shows how sensitive the answer is to that one value; each row was produced by running this calculator.
| Original price | Sale price | You save |
|---|---|---|
| 40 | 30 | 10 |
| 80 | 60 | 20 |
| 160 | 120 | 40 |
| 320 | 240 | 80 |
What happens with invalid input
These messages are produced by the calculator itself, so you know what to fix.
- Discount: entering "101" shows "Discount must be at most 100." beside that field and no result.
Choosing between the Percent Off Calculator and similar calculators
Each row shows what a related calculator on this site asks for and what it returns, so you can pick the one that matches your question.
| Calculator | You enter | It returns |
|---|---|---|
| [Percent Error Calculator](/math/percent-error-calculator/) | measured value and true value | Percent error |
| [Decimal to Percent Calculator](/math/decimal-to-percent-calculator/) | decimal | Percent |
| [Percent Increase Calculator](/math/percent-increase-calculator/) | original value and new value | Percentage increase |
| [Percent to Fraction Calculator](/math/percent-to-fraction-calculator/) | percent | Fraction |
| [Percent to Ratio Calculator](/math/percent-to-ratio-calculator/) | percent | Ratio |
Background: rounding and basic arithmetic
Rounding to a place looks at the digit just to its right: 0 to 4 rounds down and 5 to 9 rounds up (the half-up convention, so 2.5 becomes 3). Rounding 838.274 gives 800 to the nearest hundred, 840 to the nearest ten and 838 to the nearest one.
Some systems use banker's rounding (half to even), which sends 2.5 to 2 and 3.5 to 4; check which convention your task requires, and round only at the end of a multi-step calculation.
Assumptions and limitations
- 0% leaves the price unchanged
- 100% gives a price of 0
If a required value is empty, not a number, or outside its allowed range, the form marks that field with a message and shows no result instead of a misleading number. The automated checks deliberately try invalid entries for discount to confirm this.
Frequently asked questions
What is 30% off $50?
$35, because 50 × 0.70 = 35.
Does tax apply before or after the discount?
Usually after: sales tax is charged on the discounted price.
What does 0% or 100% off mean?
0% leaves the price unchanged; 100% makes it free.
What does the Percent Off Calculator calculate?
Find the sale price and savings after a percentage discount. It returns Sale price and You save.
What formula does the Percent Off Calculator use?
sale price = price × (1 − discount ÷ 100). The discount amount is price × percent ÷ 100; subtract it from the price.
What do I need to enter in the percent Off Calculator?
You enter Original price and Discount (%).
How is the result rounded or limited?
IEEE-754 double precision; shown to at most 6 decimal places. 0% leaves the price unchanged.
What are the limits of this calculator?
0% leaves the price unchanged. 100% gives a price of 0.
What is an example of a percent Off result?
With original price 80 and discount 25, the sale price is 60.
Related calculators
- Percent Error Calculator — Compare a measured value with the true value.
- Decimal to Percent Calculator — Convert a decimal to a percentage.
- Percent Increase Calculator — Percentage increase between two values.
- Percent to Fraction Calculator — Convert a percentage to a simplified fraction.
- Percent to Ratio Calculator — Express a percentage as a part-to-whole ratio.
- Percent Decrease Calculator — Percentage decrease between two values.
Sources
- OpenStax, Prealgebra 2e (Rice University): fractions, decimals, percents, ratios and rounding
Content last reviewed 2026-11-04. Formulas and worked examples are checked by automated tests against independently computed values.