Percent off calculator
- After the first discount
- You pay
- You save
- Total discount
Price before sales tax
- Price before tax
- Tax
To take a percent off, multiply the price by what is left: 20% off $80 is $80 × 0.8 = $64. Two discounts multiply rather than add: a further 10% off leaves $57.60, which is 28% off in total, not 30%.
Formula
Sale price = Price × (1 − Discount)Two discounts: Price × (1 − D1) × (1 − D2)Price before tax = Total ÷ (1 + Tax rate)
Worked example
Increase 200 by 10%, then decrease the result by 20%. What is the final amount?
- Up 10%: 200 × 1.1 = 220.
- Down 20% of the new amount: 220 × 0.8 = 176.
Answer: 176
Do it in your head: Divide by what is left
- Say what share of the original is left: 20% off leaves 80%.
- Divide the sale price by that share, written as a decimal.
- Check: the discount taken off your answer should give the sale price.
Two discounts in a row
| First | Then | Total discount |
|---|---|---|
| 10% | 10% | 19% |
| 20% | 10% | 28% |
| 20% | 20% | 36% |
| 25% | 10% | 32.5% |
| 30% | 20% | 44% |
| 50% | 20% | 60% |
| 50% | 50% | 75% |
Try three
-
What is the final price after 20% off $472?
Show the answer
$377.60
- 20% of $472 is $94.40.
- $472 − $94.40 = $377.60.
-
After 50% off, a toaster costs $65. What was the original price?
Show the answer
$130.00
- $65 is 50% of the original, so divide by 0.5: 65 ÷ 0.5 = $130.
-
A jacket is on sale for $510, which is 25% off its original price. What was the original price?
Show the answer
$680.00
- After 25% off you pay 75% of the original, so original = $510 ÷ 0.75 = $680.
- Check: 25% of $680 is $170, and $680 − $170 = $510.
That’s the idea. Keep going: 4 warm-up problems, no sign-up →
Learn it properly: Money & prices →
Questions
Is 20% off and then 10% off the same as 30% off?
No. The second discount applies to the lower price: $80 → $64 → $57.60, which is 28% off, not 30%.
How do I find the price before a discount?
Divide by what is left. After 25% off, $60 is 75% of the original: $60 ÷ 0.75 = $80.
How do I back sales tax out of a total?
Divide the total by 1 plus the tax rate. $107 with 7% tax included: $107 ÷ 1.07 = $100 before tax, and $7 of tax.
How do I work out a discount in my head?
Build it from 10%: 10% of $80 is $8, so 20% is $16 and 5% is $4.