Discount Calculator
Enter the advertised list price and discount, choose a tax rate, and state whether the list price already includes that tax. The result separates savings, tax-exclusive sale price, tax amount, and the final amount payable.
General one-price estimate only. It assumes the discount applies proportionally to the entered list price and uses the selected price basis consistently. Store rules can apply coupons, points, service fees, stacked discounts, and tax rounding in a different order; confirm the checkout amount and the correct tax rate.
Enter your scenario
Use the details that match your situation. Your estimate stays in this browser.
How this estimate works
- Savings equal the list price multiplied by the discount rate divided by 100, and the discounted price equals the list price minus those savings.
- For a tax-exclusive list price, the selected tax is added after the discount. For a tax-inclusive list price, the discounted total remains tax inclusive and its tax-exclusive component is extracted by division.
- The result keeps the advertised-basis savings, tax-exclusive sale price, tax amount, and final payable price separate so the order of operations is visible.
Official percentage and tax references
- NIST Guide to the SI: percent represents the number 0.01
- Japan National Tax Agency: 10% standard and 8% reduced consumption-tax rates
NIST defines percent as parts per hundred. The 8% and 10% options match current Japan consumption-tax rates, but the calculator does not determine which rate applies to a product or transaction.
Frequently asked questions
How do I calculate 20% off a price?
Multiply the list price by 0.20 to obtain the savings, then subtract those savings from the list price. The calculator also separates tax when requested.
What is the difference between tax-inclusive and tax-exclusive price basis?
Tax-inclusive means the entered list price already contains the selected tax. Tax-exclusive means the selected tax is added after the discount.
Can I calculate two stacked discounts?
Not in one step. Apply the first discount, then use its result as the list price for the second calculation because stacked percentages are normally sequential rather than simply added.