Enter values and select Calculate.
Calculated result
How to use this calculator
- Choose percent-off mode or reverse discount mode.
- Enter the original price as a non-negative decimal.
- Enter either the discount percentage or the sale price.
- Calculate and copy only the concise arithmetic result when needed.
Formula and method
Savings = original price × discount rate. Final price = original price − savings. Reverse discount = (original − sale) ÷ original × 100.
Worked example
A 25% discount on $100 saves $25 and produces a $75 final price. If an item falls from $100 to $70, the reverse calculation is 30% off.
Assumptions and boundaries
- Discounts from 0% through 100% are supported.
- Sales tax and jurisdiction-specific fees are not included.
- Stacked discounts are deferred to keep the interaction direct.
- A reverse-mode sale price cannot exceed the original price.
Understanding the result
The calculator preserves full finite arithmetic through the calculation and formats ordinary money to two decimal places for display. Percentages can retain additional useful decimal precision. It never evaluates expressions or silently adds tax, fees, exchange rates, or recommendations.
Common mistakes
- Adding sales tax that the tool does not calculate
- Entering 0.25 when the intended discount is 25%
- Treating sequential discounts as one added percentage
- Confusing savings with final price
Methodology note
This deterministic browser-local utility uses only the formulas stated above and the values you supply. It provides arithmetic, not financial, investment, pricing, accounting, tax, or tipping advice.
Check source values and required precision before using a result in a purchase, invoice, business record, or other decision.