How do I calculate the price at 20% off?

Multiply the list price by the “remaining share”. At 20% off, 80% remains, so it’s list price × 0.8. For 3,800, that’s 3,800 × 0.8 = 3,040. Only when you want the amount saved do you multiply by the discount rate itself: 3,800 × 0.2 = 760. Remember: for the amount you pay, use the remaining share.

What percent off is “3 wari off” (3割引)?

One wari is 10%, so 3 wari off is 30% off. Multiply the wari number by 10 to get the percent. A confusing one is the label “7 kake” (7掛け), which means you pay 70% (3 wari off). “Wari off” is the share taken off, and “kake” is the share that remains. This tool shows results in both styles.

Is “20% off, plus another 10% off” 30% off?

No, it isn’t 30% off, because the second discount applies to the price already lowered by the first. For 1,000: 1,000 × 0.8 = 800, then 800 × 0.9 = 720, which is 28% off in total. With percentage discounts, swapping the order gives the same result.

Which is calculated first, the discount or sales tax?

The discount comes first and sales tax after, because tax is charged on the amount actually received after the discount. If an item priced at 1,000 before tax is sold at 20% off, 10% tax is added to 800 for a total of 880. If the price tag includes tax, you can apply the discount to that amount directly.

Which is the better deal, 20% off or 20% points back?

20% off is better. With 20% off, you buy a 1,000 item for 800, so the discount rate is exactly 20%. With 20% points back, you pay 1,000 and get 200 points, which means paying 1,000 for 1,200 worth of shopping. As a discount rate, that’s 200 ÷ 1,200 ≈ 16.7%. Points also expire, and if you can’t use them up, that part isn’t a gain.

How do I find the discount from a price tag?

The discount rate is (list price − sale price) ÷ list price. If a list price of 4,500 is 3,150, dividing the 1,350 saved by 4,500 gives 0.3, or 30% off (3 wari off). Enter both amounts in the “Find the discount rate” tab to see the discount rate, wari, kake, and amount saved together.

To undo a 20% off price, do I add 20%?

No, because a markup is based on the lowered amount. 20% off 1,000 is 800, but adding 20% to 800 only gives 960. To get back, you need 1,000 ÷ 800 = 1.25, a 25% markup. When you find a discount rate, this tool also shows “what markup is needed to get back to the original”.

Discount Calculator (% Off, Tenths Off, Effective Price with Points Back)

Just enter “20% off”, “3 tenths off”, “another 10% off”, or “500 off” to see the amount you pay, the amount saved, and the discount rate at once. If the price tag excludes tax, sales tax is added after the discount, and entering a points-back rate shows the effective discount rate too. Includes a tab to compare side by side whether a discount or points back is the better deal, and a tab to work out the discount from the list price and sale price.

ABOUT

About Discount Calculator (% Off, Tenths Off, Effective Price with Points Back)

The discount calculator works out the amount you actually pay, the amount saved, and the discount rate all at once, just from the list price and the discount terms. You can enter discounts as “20% off”, “3 tenths off” (the Japanese wari style), or “500 off”, and it handles stacked coupons and the order of applying a discount to a pre-tax price before adding sales tax. Enter a points-back rate and it also calculates the effective discount rate combining the instant discount and the points. There’s also a tab to work out the discount from the list and sale prices, and a tab to compare side by side which of a discount, a fixed amount off, or points back is the best deal.

How to use Discount Calculator (% Off, Tenths Off, Effective Price with Points Back)

1In the “Price after discount” tab, enter the list price (the amount on the price tag)
2Choose whether the price tag includes or excludes tax (if it excludes tax, sales tax is added after the discount)
3Choose how to enter the discount (“% off”, “Tenths off”, or “Amount off”) and enter the number
4When discounts such as coupons stack, turn on “Stack another discount” and enter the second one
5If there’s points back, enter the rate and check the effective discount rate
6To find the discount rate from a price tag, enter the list and sale prices in the “Find the discount rate” tab
7In the “Compare deals” tab, list several offers and decide using the table sorted by effective discount rate

Great for

Check what you’ll pay from a sale price tag before getting in line at the register
Work out what “20% off, plus another 10% off at the register” really comes to
Work out the discount from a price tag that only shows the list and sale prices
Compare whether “20% off” or “20% points back” on the same item is the better deal
Find the tax-inclusive amount after discount up front for quotes or online shops showing pre-tax prices
Set a sale price by going back and forth between the amount off and the discount rate
Try which order to use coupons and fixed discounts in to get the lowest price when they’re mixed

Good to know

Stacked discounts don’t add up. 20% off followed by 10% off is 0.8 × 0.9 = 0.72, or 28% off in total.
With percentage discounts, swapping the order gives the same result, but when a fixed-amount coupon is mixed in, the order changes the amount. Which order applies is up to the store’s rules.
Sales tax is charged on the amount after the discount. When the price tag excludes tax, the discount is calculated first and then tax is added.
Points back is different in nature from a discount that lowers the price on the spot. 20% points back, where you pay 1,000 and get 200 points, is like paying 1,000 for 1,200 worth of shopping, so the effective discount rate is about 16.7%.
Points are calculated as 1 point = 1 currency unit, assuming you use them all. If you can’t use them before they expire, that part isn’t effectively a discount.
Points awarded are rounded down to whole numbers. Some stores award points based on the pre-tax amount, so the actual number may differ by a few points.
You can choose to round down, round, or round up fractions in the amount off and sales tax. If it’s off by 1 from your receipt, try switching.
All calculations happen in your browser, and the amounts you enter are never sent to a server.

Questions this tool answers

Use Discount Calculator (% Off, Tenths Off, Effective Price with Points Back) for searches like these:

How much is 20% off 3,800?
What percent off is 3 wari off?
What does 20% off then another 10% off really come to?
If the list price is 4,500 and it’s 3,150, what’s the discount?
I want the tax-inclusive amount after discounting a pre-tax price
Which is better, 20% off or 20% points back?
I want to work out what I pay when combining a coupon and a discount

FAQ

How do I calculate the price at 20% off?: Multiply the list price by the “remaining share”. At 20% off, 80% remains, so it’s list price × 0.8. For 3,800, that’s 3,800 × 0.8 = 3,040. Only when you want the amount saved do you multiply by the discount rate itself: 3,800 × 0.2 = 760. Remember: for the amount you pay, use the remaining share.
What percent off is “3 wari off” (3割引)?: One wari is 10%, so 3 wari off is 30% off. Multiply the wari number by 10 to get the percent. A confusing one is the label “7 kake” (7掛け), which means you pay 70% (3 wari off). “Wari off” is the share taken off, and “kake” is the share that remains. This tool shows results in both styles.
Is “20% off, plus another 10% off” 30% off?: No, it isn’t 30% off, because the second discount applies to the price already lowered by the first. For 1,000: 1,000 × 0.8 = 800, then 800 × 0.9 = 720, which is 28% off in total. With percentage discounts, swapping the order gives the same result.
Which is calculated first, the discount or sales tax?: The discount comes first and sales tax after, because tax is charged on the amount actually received after the discount. If an item priced at 1,000 before tax is sold at 20% off, 10% tax is added to 800 for a total of 880. If the price tag includes tax, you can apply the discount to that amount directly.
Which is the better deal, 20% off or 20% points back?: 20% off is better. With 20% off, you buy a 1,000 item for 800, so the discount rate is exactly 20%. With 20% points back, you pay 1,000 and get 200 points, which means paying 1,000 for 1,200 worth of shopping. As a discount rate, that’s 200 ÷ 1,200 ≈ 16.7%. Points also expire, and if you can’t use them up, that part isn’t a gain.
How do I find the discount from a price tag?: The discount rate is (list price − sale price) ÷ list price. If a list price of 4,500 is 3,150, dividing the 1,350 saved by 4,500 gives 0.3, or 30% off (3 wari off). Enter both amounts in the “Find the discount rate” tab to see the discount rate, wari, kake, and amount saved together.
To undo a 20% off price, do I add 20%?: No, because a markup is based on the lowered amount. 20% off 1,000 is 800, but adding 20% to 800 only gives 960. To get back, you need 1,000 ÷ 800 = 1.25, a 25% markup. When you find a discount rate, this tool also shows “what markup is needed to get back to the original”.

Special Thanks

SOLO GUILD | サービス作るAIエンジニア

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