Discount Calculator
Last updated
This discount calculator finds the sale price after a percentage off, works out the percentage off from two prices, stacks a second discount, or adds sales tax so you see what you’ll pay. A $80.00 jacket at 25% off costs $60.00, so you save $20.00.
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How to use the discount calculator
- Choose whether you know the percentage off, or both prices.
- Enter the original price and either the discount or the sale price.
- Open “Extra discount and sales tax” to stack a second discount or add tax.
- Read the sale price, the amount you save and the total you’ll pay.
How a discount is calculated
Sale price from a percentage off
Sale price = Original price × (1 − Discount % ÷ 100)
Percentage off from two prices
Discount % = (Original − Sale price) ÷ Original × 100
Two discounts in a row
Final price = Original × (1 − First %) × (1 − Second %)
The second discount is taken off the already reduced price, so two discounts add up to less than their sum.
Adding sales tax
Total = Sale price × (1 + Tax % ÷ 100)
Discount Calculator examples
Example 1: 25% off
A $80.00 jacket at 25% off: $80.00 × 0.75 = $60.00. You save $20.00.
Example 2: two discounts
$100.00 with 20% off, then a further 10% off: $100.00 × 0.80 = $80.00, then $80.00 × 0.90 = $72.00. That’s 28% off in total, not 30%.
Example 3: finding the percent off
The price drops from $80.00 to $60.00. ($80.00 − $60.00) ÷ $80.00 = 0.25, so it’s 25% off.
Example 4: with sales tax
The $60.00 sale price with 8% sales tax adds $4.80, for a total of $64.80.
Sale prices on a $100 item
Common discounts on a $100.00 price. For other prices, multiply by the same percentage.
| Discount | Sale price | You save |
|---|---|---|
| 5% | $95.00 | $5.00 |
| 10% | $90.00 | $10.00 |
| 15% | $85.00 | $15.00 |
| 20% | $80.00 | $20.00 |
| 25% | $75.00 | $25.00 |
| 30% | $70.00 | $30.00 |
| 40% | $60.00 | $40.00 |
| 50% | $50.00 | $50.00 |
How to find the original price
If you know the sale price and the percentage taken off, divide by what is left. Original price = Sale price ÷ (1 − Discount % ÷ 100). A $60.00 sale price after 25% off gives $60.00 ÷ 0.75 = $80.00. A $90.00 sale price after 10% off gives $90.00 ÷ 0.90 = $100.00. If you know both prices instead, choose “The % off” in the calculator.
Stacked discounts: why 20% plus 10% is not 30%
Each discount takes a share off the price left after the one before. That makes two discounts worth less than their sum, and the order doesn’t matter: $100.00 at 20% then 10% is $72.00, and 10% then 20% is also $72.00. The total discount is 1 − (1 − first) × (1 − second).
| Discounts | You pay | Total off | Adding them up would say |
|---|---|---|---|
| 10% then 10% | $81.00 | 19% | 20% |
| 20% then 10% | $72.00 | 28% | 30% |
| 20% then 20% | $64.00 | 36% | 40% |
| 30% then 20% | $56.00 | 44% | 50% |
| 50% then 20% | $40.00 | 60% | 70% |
A “50% off, then an extra 20% off” sale is 60% off in total, which leaves $40.00 from $100.00.
Sales tax and coupons
For a percentage discount the order of tax and discount doesn’t change what you pay: $80.00 at 25% off plus 8% tax is $64.80 either way. A fixed-dollar coupon can behave differently. A $10.00 coupon on $80.00 with 8% tax costs $75.60 if it reduces the price before tax, or $76.40 if tax is worked out on the full $80.00 first and the coupon comes off afterwards. Whether a coupon reduces the taxable amount depends on the state and the kind of coupon, so check your receipt or your state’s revenue department.
Is the discount real?
A percentage off only means something if the starting price was real. A jacket shown as $100.00, now $50.00, looks like 50% off. If it usually sells for $70.00, the real saving against the usual price is ($70.00 − $50.00) ÷ $70.00 = 28.6%. The U.S. Federal Trade Commission’s guide on former price comparisons (16 CFR 233.1) says a former price is a legitimate basis for a comparison if it was the actual, bona fide price at which the item was offered to the public on a regular basis for a reasonably substantial period of time, and that an artificial, inflated price set up so a large reduction can be advertised makes the bargain a false one. Source: 16 CFR 233.1, Former price comparisons. Check the price history, or the same item at other stores, before you decide a sale is a good one.
If you are the one giving the discount
A discount comes out of your margin, not just your revenue. An item that costs $60.00 and lists at $100.00 earns $40.00 a unit, a 40% margin. At 20% off it sells for $80.00 and earns $20.00, a 25% margin. To earn the same total profit you would have to sell 2 times as many units. Use the profit margin calculator to check a sale price before you set it, and the markup calculator to see whether the price still covers your cost.
Discount Calculator questions
How do I calculate a percentage discount?
Multiply the original price by the discount as a decimal to get the amount off, then subtract it. 25% off $80.00: $80.00 × 0.25 = $20.00 off, so the sale price is $60.00. A faster way is to multiply by what you pay: $80.00 × 0.75 = $60.00.
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. ($80.00 − $60.00) ÷ $80.00 = 0.25, so 25% off.
What is 20% off then another 10% off?
Not 30% off. The second discount applies to the already reduced price: $100.00 × 0.80 = $80.00, then $80.00 × 0.90 = $72.00. The total discount is 28%.
Is sales tax added before or after the discount?
This calculator applies tax to the discounted price: $80.00 at 25% off is $60.00, and 8% tax on $60.00 is $4.80, so you pay $64.80. For a percentage discount the total is the same either way, because multiplication can be done in any order. A fixed-dollar coupon can differ, depending on whether it reduces the taxable price. Rules vary by state and by type of coupon, so check your receipt.
How do I find the original price after a discount?
Divide the sale price by one minus the discount. If a jacket costs $60.00 after 25% off, the original price was $60.00 ÷ 0.75 = $80.00. Do not add 25% to $60.00: that gives $75.00, because the 25% was taken off the original, not off the sale price.
How do I calculate two discounts?
Multiply the remaining shares. 20% off then 10% off leaves 0.80 × 0.90 = 72% of the price, so $100.00 becomes $72.00, a 28% discount. The order doesn’t change the result. Use the extra-discount box to do it in the calculator.
What does buy one get one 50% off really save?
On two $40.00 items you pay $40.00 + $20.00 = $60.00 instead of $80.00, which is 25% off the pair. Buy one get one free is 50% off. The calculator doesn’t take these offers directly, but you can enter the full price of both items and the sale price you pay to get the percent off.
Is a “was” price always real?
No. The Federal Trade Commission’s guide on former price comparisons says a former price is a legitimate basis for a sale claim if it was the actual, bona fide price at which the item was offered to the public on a regular basis for a reasonably substantial period of time. If the higher price was artificial or inflated just so a big reduction could be advertised, the bargain is a false one. If a discount looks too good, check what the item usually sells for.
How do I calculate a discount in my head?
Take 10% by moving the decimal point one place, then build up: 10% of $80 is $8, so 20% is $16 and 25% is $20.
Can I use it for a markdown from a price increase?
The “% off” calculation only covers price decreases. If the new price is higher than the original, the calculator tells you there’s no discount.
What this calculator doesn’t do
- It works on one item or one total. It doesn’t handle buy-one-get-one offers, minimum spends or coupon rules.
- It applies sales tax as a single percentage on the final price. Tax rules differ by place and by item.
- It rounds only when it displays results, so a store receipt may differ by a cent.
Results are estimates for planning, not financial advice. The methodology page explains how every calculator here is built and checked.