Discount Calculator
Calculate the sale price and how much you save for any discount percentage. Supports stacked discounts and percent-off math.
How to Use This Calculator
- Enter the original price
- Enter the discount percentage (e.g. 25 for 25% off)
- (Optional) Add a second discount to stack two offers, or a sales tax rate
- See the final price, your savings, and the effective discount instantly
🏷️ How to Calculate a Discount
Sale price = Original × (1 − Discount ÷ 100). For $80 at 25% off: $80 × 0.75 = $60.00, and you save $20.00.
Stacked discounts multiply, they don't add. "25% off, then an extra 20% off" is 0.75 × 0.80 = 0.60 of the original — a 40% effective discount, not 45%.
💡 Quick Mental-Math Tricks
- 10% off: move the decimal one place left ($80 → save $8).
- 20% off: take 10% and double it ($80 → save $16).
- 25% off: divide by 4 to get the savings ($80 ÷ 4 = $20).
- 50% off: just halve it.
Frequently Asked Questions
How do you calculate a discount?
Multiply the original price by (1 − discount ÷ 100). For $80 at 25% off: $80 × 0.75 = $60.00, so you save $20.00.
How do I calculate percent off?
The savings equal Price × (Percent ÷ 100), and the sale price is what's left. 30% off a $50 item saves $15 and costs $35.
How do stacked discounts work?
Stacked discounts multiply rather than add. '25% off, then an extra 20% off' is 0.75 × 0.80 = 0.60 of the original price — a 40% effective discount, not 45%.
What is the final price after a 25% discount?
The final price is 75% of the original. A $120 item at 25% off costs $90.00, saving you $30.00.
How do I find the original price from a sale price?
Divide the sale price by (1 − discount ÷ 100). If something costs $60 after 25% off, the original was $60 ÷ 0.75 = $80.00.