The Three Discount Formulas
Find the Sale Price
Sale Price = Original Price × (1 − Discount% ÷ 100)
Example: $100 × (1 − 0.25) = $75
Find the Discount Amount
Discount Amount = Original Price × (Discount% ÷ 100)
Example: $100 × 0.25 = $25 saved
Find the Discount Percentage
Discount% = ((Original − Sale) ÷ Original) × 100
Example: ((100 − 75) ÷ 100) × 100 = 25%
Quick Discount Reference Table
| Original Price | 10% Off | 20% Off | 30% Off | 50% Off |
|---|---|---|---|---|
| $25 | $22.50 | $20.00 | $17.50 | $12.50 |
| $50 | $45.00 | $40.00 | $35.00 | $25.00 |
| $100 | $90.00 | $80.00 | $70.00 | $50.00 |
| $150 | $135.00 | $120.00 | $105.00 | $75.00 |
| $200 | $180.00 | $160.00 | $140.00 | $100.00 |
| $500 | $450.00 | $400.00 | $350.00 | $250.00 |
Frequently Asked Questions
How do you calculate a discount percentage?
Discount % = ((Original Price − Sale Price) ÷ Original Price) × 100. If an item was $80 and is now $60: ((80 − 60) ÷ 80) × 100 = 25% discount.
How do you find the sale price after a discount?
Sale Price = Original Price × (1 − Discount % ÷ 100). For a 30% discount on $120: $120 × (1 − 0.30) = $120 × 0.70 = $84.
How do you calculate multiple discounts?
Apply them sequentially, not additively. A 20% discount followed by a 10% discount is NOT 30% off. $100 → 20% off = $80 → 10% off = $72. Total discount = 28%, not 30%.
What is the difference between discount and markdown?
A discount is a temporary price reduction (sale, coupon). A markdown is a permanent price reduction, often used in retail to clear inventory. Both use the same calculation formula.
How do retailers calculate discount pricing?
Retailers use keystone pricing (2× cost) then apply discounts. A product costing $25 is priced at $50 (keystone). A 40% off sale brings it to $30, still maintaining $5 profit margin.