Reviewed by:
David Chen, CFA | Financial Modeling and Valuation Analyst
Use our comprehensive calculator to determine the final cost of an item after applying both percentage and fixed-amount coupons. You can also solve for the original price, the percentage discount, or the fixed discount amount by leaving one field blank.
Calculate Cost with Coupon
Calculation Result
Detailed Steps
Coupon Cost Formula
The general formula for calculating the final cost (C) after a percentage discount (D%) and a fixed amount discount (F) is:
$$C = P \cdot \left(1 – \frac{D\%}{100}\right) – F$$
Where: P = Original Price, D% = Percentage Discount, F = Fixed Discount Amount.
Formula Sources: Investopedia: Discount, The Balance: How to Calculate a Discount
Variables Explained
- Original Price ($): The starting price before any discounts are applied.
- Final Cost After Coupon ($): The price the customer pays after all coupons are deducted.
- Percentage Discount (%): The discount rate applied to the original price (e.g., 10%).
- Fixed Discount Amount ($): A flat dollar amount subtracted from the price after the percentage discount (e.g., $5 off).
What is Coupon Cost?
The term “Coupon Cost” or “Final Cost with Coupon” refers to the ultimate price a consumer pays for a good or service once all promotional deductions, or coupons, have been factored in. This is the net amount that clears the transaction and is arguably the most important metric for consumers making purchasing decisions.
Calculating this cost accurately is crucial for budgeting and financial planning, especially when complex sales or promotions involve multiple types of discounts—such as a percentage markdown combined with a fixed dollar-amount coupon or store credit. Our calculator simplifies this process by handling these simultaneous deductions.
How to Calculate Coupon Cost (Example)
Let’s calculate the Final Cost for a product with an Original Price of $200, a 15% discount, and a $10 fixed coupon.
- Identify the Original Price (P): $200.
- Calculate the Percentage Discount Amount: Multiply the Original Price by the Percentage Discount ($200 \times 15\% = $30.00).
- Subtract the Percentage Discount: Subtract the calculated amount from the Original Price ($200 – $30.00 = $170.00).
- Subtract the Fixed Discount Amount (F): Subtract the fixed coupon from the result of Step 3 ($170.00 – $10.00 = $160.00).
- The Final Cost (C) is $160.00.
Frequently Asked Questions (FAQ)
A: In most retail scenarios, the percentage discount is applied first to the original price, and then any fixed dollar amount is subtracted from the resulting subtotal. Our calculator follows this standard industry practice.
A: Yes. By leaving the “Original Price” field blank and entering the other three values (Final Cost, Percentage Discount, Fixed Discount), the calculator will reverse the formula to determine the Original Price.
A: The calculator will flag this as an error because the final cost cannot be negative in a typical purchase. It ensures the calculation results in a non-negative, physically possible value.
A: The maximum valid percentage discount is 99.99%. A discount of 100% or more leads to a denominator of zero or a negative value in the formula to solve for Original Price, making the calculation unstable and nonsensical.