Discount Calculator
This discount calculator works out the sale price after a percentage off and how much you save. It can also apply an extra discount on top, such as a coupon on an item that's already reduced, and add sales tax to give the total at the register.
Result
Sale price: $60.00
| You save | $20.00 |
|---|
Results update as you type.
How to Calculate a Discount
- Amount off = original price × discount ÷ 100
- Sale price = original price − amount off, or original price × (1 − discount ÷ 100)
Extra discounts
Final price = original × (1 − first discount) × (1 − extra discount)
Total discount = 1 − (1 − first) × (1 − extra)
With sales tax
Total = sale price × (1 + tax rate)
Worked Example
A $80 jacket at 25% off, with an extra 10% coupon and 8% sales tax:
- First discount: 80 × 0.75 = $60
- Extra 10%: 60 × 0.90 = $54
- You save: 80 − 54 = $26, which is 32.5% off in total
- Sales tax: 54 × 0.08 = $4.32
- Total at the register: $58.32
Quick Mental Math
- 10% off: move the decimal one place left. 10% of $45 is $4.50.
- 20% off: double the 10%. 20% of $45 is $9.
- 25% off: take a quarter. 25% of $80 is $20.
- 50% off: halve it.
- 15% off: 10% plus half of 10%. 15% of $60 is $6 + $3 = $9.
Tips
Compare the final price, not the percentage
A smaller discount on a cheaper item can still cost less. Compare the price you’ll pay.
Buy now, pay later
A discount is quickly wiped out by credit card interest if the balance isn’t paid in full; the credit card payoff calculator shows how much interest adds up.
Other percentage questions
For percent change, percent of a number and more, use the percentage calculator. To add tax to any price, try the sales tax calculator.
Frequently Asked Questions
How do I calculate a discount?
Multiply the price by the discount as a decimal to get the amount off, then subtract it. 25% off $80 is 0.25 × 80 = $20 off, so the sale price is $60. You can also multiply by what's left, 80 × 0.75 = $60.
What is 20% off $50?
20% of $50 is $10, so the sale price is $40. Moving the decimal point one place gives 10%, $5, and doubling it gives 20%.
How do stacked discounts work?
Each discount applies to the price after the one before. 25% off and then an extra 10% off is not 35% off. $80 becomes $60, then 10% off $60 is $54, which is 32.5% off the original price.
How do I work out the original price from a sale price?
Divide the sale price by what's left after the discount. If $60 is the price after 25% off, the original was 60 ÷ 0.75 = $80. Don't add 25% back on, which would give $75.
Is sales tax charged on the original price or the sale price?
Usually on the price you actually pay after store discounts. Rules for manufacturer coupons and rebates vary by state, so check your state's rules if it matters.
How do I find the percent off from two prices?
Subtract the sale price from the original, divide by the original and multiply by 100. A $120 item on sale for $90 is (120 − 90) ÷ 120 × 100 = 25% off. The percentage calculator's percent-change mode does this too.
Related Calculators
- Percentage CalculatorPercent of a number, what percent X is of Y, and percent change.
- Sales Tax CalculatorAdd sales tax to a price, or remove it from a total.
- Savings Goal CalculatorHow much to save each month to reach a target by a date.
- Credit Card Payoff CalculatorMonths to pay off a card balance, or the payment needed to clear it.
- Ratio CalculatorSimplify a ratio, or solve A : B = C : D for a missing value.
Sources & Assumptions
- OpenStax, Prealgebra 2e — Section 6.3, Solve Sales Tax, Commission, and Discount Applications
- An extra discount is applied to the already-reduced price, as stores usually apply a coupon to a sale item. Sales tax is added to the final sale price.
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