Discount Calculator
Calculate discounted prices with single or stacked discounts and tax.
The Discount Calculator helps you understand the true final price after applying discounts and taxes. It handles stacked discounts (where each discount applies to the already-reduced price) and shows the impact of tax timing (applied before or after discounts). Essential for comparing deals and understanding your actual savings.
Examples
Simple 25% Off
Stacked Discounts
Frequently Asked Questions
Is 20% off plus 10% off the same as 30% off?
Should tax be applied before or after discount?
How do I calculate the original price from the sale price?
Quick Tips
- •Stacked discounts do not simply add up. A 20% + 10% discount is 28%, not 30%.
- •Some stores apply tax before discounts, costing you more in taxes.
- •Compare the final price across stores, not just the discount percentage.
The Discount Calculator helps you understand the true final price after applying discounts and taxes. It handles stacked discounts (where each discount applies to the already-reduced price) and shows the impact of tax timing (applied before or after discounts). Essential for comparing deals and understanding your actual savings.
How to Use This Calculator
Enter the original price and discount percentage. Optionally add a second stacked discount and a tax rate. Toggle whether tax is applied before or after discounts. Click Calculate to see the final price and total savings.
Understanding the Formula
Discounted Price = Original Price x (1 - Discount%). For stacked discounts: Price = Original x (1 - D1%) x (1 - D2%). Tax is applied on the resulting price or original price depending on your selection.
Examples
Simple 25% Off
A $80 item at 25% off: $80 x (1 - 0.25) = $60. You save $20.
Stacked Discounts
A $100 item with 20% off then 10% off: $100 x 0.80 = $80, then $80 x 0.90 = $72. Total savings: $28 (28% effective discount, not 30%).
Frequently Asked Questions
Is 20% off plus 10% off the same as 30% off?
No. Stacked discounts are applied sequentially. 20% off then 10% off gives an effective discount of 28%, not 30%. The second discount applies to the already-reduced price.
Should tax be applied before or after discount?
In most US jurisdictions, sales tax is applied to the final sale price (after discount). However, some states or situations may differ. Check your local tax rules.
How do I calculate the original price from the sale price?
Divide the sale price by (1 - discount%). For example, if the sale price is $60 after 25% off: $60 / 0.75 = $80 original price.
Assumptions & Limitations
- Discount rates are straightforward percentages; some promotions use more complex formulas (e.g., "buy 2 get 1 free").
- Tax rate is constant and applies uniformly; some jurisdictions have category-specific tax rates.
- Tax is applied to individual items; bulk discounts or bulk tax calculations are not modeled.
- No additional fees (shipping, processing) are included in the calculation.
- Discounts stack multiplicatively (each discount applies to the reduced price), not additively.