Math
Discount Calculator
Calculate the discount amount and final price by entering the original price and discount rate (%). Useful for sales and price negotiations.
Result
| Original price | ¥ {{ fmt(result.original) }} |
| Discount | − ¥ {{ fmt(result.discountAmount) }} |
| Final price | ¥ {{ fmt(result.finalPrice) }} |
Tips
- "20% off" and "pay 80% of the price" mean the same thing.
- Stacked discounts are multiplicative, not additive. 10% off then 5% off = 0.9 × 0.95 = 85.5% of original (14.5% total off).
- Applying the discount to the tax-inclusive price vs. the tax-exclusive price can yield different final amounts.
- Fractions are rounded to the nearest whole number.
Note — The Illusion That "One Free" Beats "Half Price"
Behavioral economics research shows that "50% off" and "get the same amount free" are mathematically identical in value, yet most people perceive the latter as a better deal. Campaign experiments consistently show that bonus-item offers drive more sales.
Anchoring, loss aversion, and price-point framing mean human price perception operates far from pure mathematics. Use this discount calculator to see the actual value clearly.