Discount Calculator
Find the sale price after a percent-off or dollar-off discount, an optional second stacked percentage, and optional sales tax. The calculator separates savings before tax from the final checkout price.
Discount Calculator tool
About the Discount Calculator
Use it to compare coupons, promotions, and advertised discounts without mistakenly adding stacked percentages. Results are estimates, not financial advice.
How Is Discount Calculated?
Apply the first discount, then apply the second percentage to the remaining price. Sales tax applies to that discounted subtotal. Savings and effective discount are measured before tax.
Percent discount subtotal = price × (1 − first percentage ÷ 100)
Dollar discount subtotal = price − dollars off
Discounted price = subtotal × (1 − second percentage ÷ 100)
Final price = discounted price × (1 + tax percentage ÷ 100)
Effective discount = savings ÷ original price × 100
Example
A $100 item with 20% off and then another 10% off costs $72 before tax. At 5% sales tax, checkout is $75.60. Savings are $28 and the effective discount is 28%.
How to Use the Discount Calculator
- Enter the original price.
- Choose percent off or dollars off and enter the first discount.
- Enter any second percentage discount, or zero.
- Enter the applicable sales tax percentage, or zero.
- Compare final price, pre-tax savings, and effective discount.
Discount Calculator Examples
Stacked percentages
20% off followed by 10% off a $100 item gives $80 × 0.90 = $72, not $70.
Dollar coupon
A $50 item with a $10 coupon and then 25% off costs $30 before tax. Savings are $20, or 40%.
Coupon order
Two percentage discounts commute, but a dollar coupon and a percentage discount may not. This calculator always applies the first chosen discount before the second percentage.
Checkout limitations
Shipping, fees, minimum purchase requirements, coupon exclusions, and item-by-item tax rounding are not included.
Frequently Asked Questions
Can I add discount percentages?
No. Each percentage applies to the remaining price. Two 20% discounts produce a 36% effective discount.
When is sales tax applied?
After both discounts in this model. Local coupon and tax rules may differ.
Do savings include sales tax?
No. Savings and effective discount compare original and discounted pre-tax prices.
Can the discount exceed the original price?
No. A percent discount must be at most 100%, and a dollar discount cannot exceed the original price.
What happens with a zero original price?
The final price and savings are zero. Effective discount is displayed as zero because division by zero is undefined.