Discount Calculator

Calculate the sale price after a discount, the savings, and the percent off between two prices. Recover the original price or compare two stacked discounts. Use a period as the decimal separator.

Choose what you want to calculate

Enter the original price and the percent off to get the sale price and how much you save.

Enter the original price and the sale price to get the discount percentage and the savings.

Enter the price you paid and the percent already applied to recover the original price.

Enter the original price and two stacked discounts to get the sale price and the effective discount.

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%

Original price =

Price after the first discount =

Sale price =

Savings =

Discount =

Effective discount =

Formula used for the calculation:

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How to use this discount calculator

Each tab title is the result you will get. The calculator finds the sale price, the savings, and the percent off. If the tag does not show the %, or it advertises 20% off plus an extra 10%, switch tabs.

To use it, follow these steps:

  1. Choose the tab for what you want to calculate: sale price (you know the original and the %), percent off (you know original and sale price), original price (you know what you paid and the % already applied), or stacked (two discounts in a row).
  2. Enter the two values you already know. If a value has decimals, use a period as the separator, for example 19990.5 or 12.5.
  3. Write the discount as a percentage: 20 means 20%, not 0.20. Under Decimal precision you choose 0 to 4 digits; the default is 2.
  4. Press Calculate. You will see the original price, the sale price, the savings, and the percentage, with the formula for that calculation. The copy button next to each figure pastes the result so you do not have to retype it.

The calculation does not depend on the currency: it works the same with dollars, euros, or any other. If you need to add VAT after the markdown, use the VAT Calculator on the already discounted price.

What is a discount?

A discount is a reduction applied to a reference amount: a price, a debt, a fee, or an interest charge. It can be a fixed amount (10 off) or a percentage of that amount. In retail it is the markdown the seller grants from the list price or from a previous value.

This calculator covers the usual case: a percent off a selling price. 20% off 100 leaves the item at 80, and the savings are 20. Taking a percentage off means subtracting that share of the price, not dividing the price by 20.

The percentage on the tag is not always the real saving. An “up to 70% off” often applies only to some items, and an inflated list price can make a weak markdown look large. Compare the sale price with what the same product cost recently, not only with the list price. A discount is also not the seller's margin: the margin is internal; what matters to you is what you pay.

It is not a generic percentage of an amount either. If you want “what is A% of B” or a markup, use the Percentage Calculators. This tool is built for prices: original, markdown, and what you pay, whether it is a product, an invoice value, or an amount on sale.

How to calculate a discount

To calculate a discount you need two of these three figures: the original price, the percent off, and the sale price. The third one is solved for. It does not matter whether it is a product price, a value, or an amount: the math is the same. Write the percentage as a percent (20 for 20%) and divide by 100 when it enters the calculation.

How to find the sale price from a percent off

When you know the original price and the percent off:

  1. Turn the discount into a decimal: 20/100 = 0.20.
  2. Subtract that decimal from 1 to see what share of the price remains: 1 − 0.20 = 0.80.
  3. Multiply the original by that factor: 100 × 0.80 = 80. The savings are what was subtracted: 100 − 80 = 20.

Sale price = Original price × (1 − Discount / 100)

Savings = Original price − Sale price

How to calculate the percent off from the original price and the sale price

When you know the original price and the sale price, and you want to check whether the advertised percentage is true:

  1. Subtract the sale price from the original: 120 − 90 = 30. That difference is the savings.
  2. Divide the savings by the original: 30/120 = 0.25.
  3. Multiply by 100: 0.25 × 100 = 25. The real discount is 25%.

Discount % = ((Original price − Sale price) / Original price) × 100

How to recover the original price from the sale price and the percent off

When you know what you paid and the percentage already applied, you have to divide by what remains of the price, not multiply by 1 plus the discount:

  1. Turn the discount into what remains of the price: 1 − 20/100 = 0.80.
  2. Divide the sale price by that factor: 80/0.80 = 100.

Original price = Sale price / (1 − Discount / 100)

A common mistake is Sale price × (1 + Discount / 100). That does not recover the list price. With 80 and 20%, the correct calculation is 80/0.80 = 100, not 80 × 1.20 = 96.

Stacked discounts: why they do not add up

Two stacked discounts do not add up. The second percentage applies to the price that already dropped, not to the original. “20% off and an extra 10%” is not 30%.

The correct way is to multiply what remains after each markdown:

Sale price = Original price × (1 − d1/100) × (1 − d2/100)

Effective discount % = (1 − (1 − d1/100) × (1 − d2/100)) × 100

On 100, 20% off leaves 80. The extra 10% falls on those 80 and subtracts 8. The sale price is 72 and the real savings are 28, that is 28%, not 30%. The order of two percentage discounts does not change the result: 20% then 10% is the same as 10% then 20%.

A single discount is one percentage off the original. If the promotion stacks two (20% and an extra 10%), it is no longer a single rate: the Stacked tab applies both markdowns in sequence and shows the effective percentage.

Practical discount examples

Example 1: 10% off a product

A product is 100 with 10% off:

Sale price = 100 × (1 − 10/100) = 100 × 0.90 = 90

Savings = 100 − 90 = 10

You pay 90 and save 10. 10% of a price is that price with the decimal point shifted one place to the left.

Example 2: the tag does not show the percentage

The original price is 120 and the sale price is 90, with no % stated:

Discount % = ((120 − 90)/120) × 100 = 25%

The real markdown is 25% and the savings are 30. Use it to check whether the advertised discount matches the two prices.

Example 3: 20% off plus an extra 10% in a promotion

A store advertises 20% off and, at checkout, an extra 10% on an item priced 100. Do not add the two markdowns. Apply one first and, on what remains, the other:

Price after 20% = 100 × (1 − 20/100) = 80

Sale price = 80 × (1 − 10/100) = 72

Effective discount = (1 − 0.80 × 0.90) × 100 = 28%

You pay 72, not 70. The real savings are 28, a 28%: the second 10% is calculated on 80, not on 100. The 30% you get by adding 20 and 10 does not exist. On the Stacked tab you see that effective percentage.

How to calculate a discount in Excel

Put the original price in A2, the discount percentage in B2 (20 for 20%, not 0.20) and, if you have it, the sale price in C2.

Sale price from the original and the percentage

Multiply the price by what remains after the markdown: =A2*(1-B2/100). If A2 is 100 and B2 is 20, the result is 80.

Percent off between two prices

Divide the difference by the original price: =(A2-C2)/A2. Format the cell as a percentage, or multiply by 100 if you want the number 25 instead of 0.25.

Original price from the sale price

Divide the sale price by the complement of the discount: =C2/(1-B2/100). With C2 equal to 80 and B2 equal to 20, you recover 100.

Two stacked discounts

If the second percentage is in C2: =A2*(1-B2/100)*(1-C2/100). With 100, 20, and 10 the result is 72.