Discount Calculator — % Off, Markdown & Half-Price in One Click
Enter the price and discount rate (%) to get the discount amount, final price, and rounding — free, no sign-up. Also explains why stacked discounts multiply, not add.
Result
| Original price | ¥ {{ fmt(result.original) }} |
| Discount | − ¥ {{ fmt(result.discountAmount) }} |
| Final price | ¥ {{ fmt(result.finalPrice) }} |
What Is a Discount Calculation?
A discount is worked out by multiplying the original price by «1 − the discount rate». At 20% off, the amount you pay is the price times 0.8, and the gap from the original price is the discount amount. This calculator takes the original price and the discount rate and shows both figures at once. «How much comes off» and «what I actually pay» are easy to mix up, so the tool puts them side by side.
Bear in mind that the same rate applied to a pre-tax price and to a tax-inclusive price can lead to different final amounts, so decide which basis you are working from before you compare. In Japan you will also still see rates quoted in wari, a tenths-based notation where 1 wari equals 10%, so «2 wari off» means 20% off. When comparing offers, convert everything to the same notation first.
How to Use the Discount Calculator
- Enter the original price Type the price before any reduction. Keep pre-tax or tax-inclusive consistent with whatever you are comparing against.
- Enter the discount rate For «20% off», enter 20. If the offer is quoted in Japanese wari, multiply by ten first — «2 wari off» becomes 20.
- Check the discount amount and the price you pay Both the amount taken off and the discounted price appear together. Use the discounted price when checking against a budget, and the discount amount when you want to state the size of the reduction.
Tips for getting more out of it
- "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.
When a Discount Calculation Comes in Handy
Confirming what a sale item will cost
When the tag shows only a percentage, you can work out the actual amount before you reach the till and decide on the spot whether it fits your budget.
Comparing coupons on unlike terms
Recalculate offers such as «500 yen off» and «15% off» against the same item price to see which wins. The higher the price, the more a percentage tends to beat a flat amount.
Lining up prices from several shops
Convert shops with different list prices and rates into discounted prices to compare them fairly. A steep discount off a high list price is not automatically the cheaper deal.
Setting a reduction as the seller
Work backwards from your target selling price and adjust the rate, watching where the final figure lands as you go.
Discount Terms Explained
- Discount Rate
- The proportion taken off the original price, normally written as a percentage. At 20% off, 20% of the original price is deducted.
- Discount Amount
- The money actually taken off, found by multiplying the original price by the discount rate.
- Payment Ratio
- The proportion you still pay after the discount. At 20% off the payment ratio is 80%, so multiplying the original price by 0.8 gives the amount due.
- Wari (Tenths Notation)
- A Japanese way of stating proportions using wari and bu. One wari is 10% and one bu is 1%, so «2 wari off» means the same as 20% off.
- Rounding Rule
- How the decimals in the result are turned into a whole number. This tool rounds to the nearest unit, but individual shops may round down or up instead.
- Stacked Discounts
- Applying one discount on top of another. The rates multiply rather than add, so the combined reduction is smaller than the two figures suggest.
FAQ
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.