Percent Off Calculator
Apply one percentage discount to an original price, then optionally apply sales tax to the discounted amount. The calculator separates savings, tax, and checkout total so their order is explicit.
How to use this calculator
Enter original price, one discount percentage, and an optional sales-tax percentage.
Review whether discounts are sequential or additive, coupon limits, tax order, exclusions, and currency.
Read price after discount, dollar savings, sales tax, and checkout total.
Formula
Savings = original price × discount rate. Discounted price = original price − savings. Sales tax = discounted price × tax rate; checkout total = discounted price + tax.
Worked example
A $100 item at 20% off costs $80 before tax; a 10% tax on that discounted price adds $8 for an $88 checkout total.
Assumptions and limits
- The calculator applies one discount before the entered tax rate and does not infer stacked coupons, exemptions, quantity pricing, or local tax law.
- Percent Off Calculator treats the entered values as estimates and does not infer missing project, account, or personal details.
- Calculations retain working precision except where the cited method requires an intermediate rounding step; displayed values are then formatted separately. Source rules and dated rates must be rechecked when they change.
Sources
- OpenStax: College Algebra 2eAlgebraic, ratio, radical, equation, and function formulas. Reviewed 2026-08-14.
- OpenStax: Prealgebra 2eOfficial formula or method source used by this calculator. Reviewed 2026-08-14.
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Verification
How this calculator is checked
Trust comes from reproducible evidence, not model confidence. You can inspect the formula, assumptions, worked example, and cited sources on this page.
- Versioned calculationFormula logic is kept separate from the interface and covered by automated registry and behavior checks.
- Cited evidenceSources linked for independent checking: 2.
- Transparent AI useAI may assist drafting or adversarial review. Agreement between models is not proof, and no human expert review is claimed unless a named reviewer is shown.
Frequently asked questions
How does the Percent Off Calculator work?
Savings = original price × discount rate. Discounted price = original price − savings. Sales tax = discounted price × tax rate; checkout total = discounted price + tax.
What information should I enter in the Percent Off Calculator?
Enter original price, one discount percentage, and an optional sales-tax percentage, then verify whether discounts are sequential or additive, coupon limits, tax order, exclusions, and currency.
What should I verify before using this Percent Off Calculator result?
The calculator applies one discount before the entered tax rate and does not infer stacked coupons, exemptions, quantity pricing, or local tax law.
Last updated 2026-08-25 · discount-tax-v2 · content-2026-08-14 · Published by YunFanLabs