Sale Price vs. Discount Rate: Reverse Markdown Math
In retail commerce, buyers and merchants frequently need to move backwards from known register prices to determine the underlying discount percentage. Understanding the relationship between original list price and sale price allows you to calculate markdown percentages instantly.
Reverse Discount Formulas
To determine the discount percentage when given the original list price and final sale price:
Discount Rate % = ((List Price − Sale Price) ÷ List Price) × 100
To determine the original list price when given the final sale price and discount percentage:
Original List Price = Sale Price ÷ (1 − (Discount Rate ÷ 100))
Worked Example: An item listed for $120.00 is purchased for $90.00. What was the discount %?
- Calculate dollar savings: $120.00 − $90.00 = $30.00 saved
- Divide savings by original list price: $30.00 ÷ $120.00 = 0.25
- Convert to percentage: 0.25 × 100 = 25% discount
Frequently Asked Questions
How do I find the original price if a product costs $60 after a 25% discount?
Divide the sale price by (1 − 0.25 = 0.75): $60 ÷ 0.75 = $80.00 original price.
Related Calculator Tools
- Discount Calculator — Calculate markdown percentages and savings.
- Reverse Percentage Calculator — Back-calculate original base prices.