How to Calculate Discount Percentage and Final Price

A discount reduces an original price by a stated percentage. You can calculate the amount saved, the final sale price, or the discount percentage when you know the original and sale prices.

The most common formulas are:

Discount amount = Original price × Discount percentage ÷ 100

Final price = Original price − Discount amount

Or in one step:

Final price = Original price × (1 − Discount percentage ÷ 100)

Use the Discount Calculator to calculate the discount amount and final price instantly.

How to calculate a discount amount

Suppose an item costs $120 and is discounted by 25%.

First calculate the amount saved:

120 × 25 ÷ 100 = 30

The discount amount is $30.

Then subtract the discount from the original price:

120 − 30 = 90

The final sale price is $90.

How to calculate the final price after a discount

You can combine the steps by multiplying the original price by the percentage that remains after the discount.

For a 25% discount, 75% of the price remains:

120 × 0.75 = 90

So the final price is $90.

This approach is often faster when you only need the sale price.

How to calculate discount percentage from original and sale price

If you know the original price and sale price, first find the price reduction:

Price reduction = Original price − Sale price

Then divide by the original price:

Discount percentage = ((Original price − Sale price) ÷ Original price) × 100

For example, an item falls from $80 to $60:

1. Reduction: 80 − 60 = 20
2. Divide by original price: 20 ÷ 80 = 0.25
3. Convert to a percentage: 0.25 × 100 = 25%

The discount is 25%.

This is a price-specific version of the Percentage Decrease Calculator.

10% discount example

Original price: $50

Discount amount:

50 × 0.10 = 5

Final price:

50 − 5 = 45

A 10% discount reduces $50 to $45.

20% discount example

Original price: $150

150 × 0.20 = 30

150 − 30 = 120

A 20% discount reduces $150 to $120.

25% discount example

Original price: $200

200 × 0.25 = 50

200 − 50 = 150

A 25% discount reduces $200 to $150.

30% discount example

Original price: $90

90 × 0.30 = 27

90 − 27 = 63

A 30% discount reduces $90 to $63.

50% discount example

Original price: $240

240 × 0.50 = 120

240 − 120 = 120

A 50% discount cuts the original price in half, so the sale price is $120.

How to find the original price before a discount

Sometimes you know the sale price and the discount percentage but need the original price.

Use:

Original price = Sale price ÷ (1 − Discount percentage ÷ 100)

Suppose a product costs $72 after a 20% discount.

Since 80% of the original price remains:

72 ÷ 0.80 = 90

The original price was $90.

A common mistake is to add 20% to the sale price. That does not reverse a 20% discount because the percentage is being applied to a different baseline.

Multiple discounts are not simply added

If an item receives two discounts in sequence, calculate each discount from the price that exists at that step.

For example, start with $100 and apply 20% off:

100 × 0.80 = 80

Then apply an additional 10% off:

80 × 0.90 = 72

The final price is $72.

The combined reduction is 28%, not 30%.

You can find the effective discount by comparing the final price with the original price:

((100 − 72) ÷ 100) × 100 = 28%

Discount percentage vs percentage decrease

A discount is a specific type of percentage decrease where the original price is the baseline.

The mathematics is the same:

((Original − New) ÷ Original) × 100

Use the Percentage Decrease Calculator for general before-and-after values and the Discount Calculator when the context is pricing.

Discount vs markup

A discount reduces a selling price. Markup increases a price relative to cost.

For example, if a product costs a business $80 and sells for $100, the markup is based on the $80 cost. If the $100 selling price is later discounted to $90, the discount is based on the $100 original selling price.

These percentages use different baselines, so they should not be treated as interchangeable.

Use the Markup Calculator when calculating selling-price markup from cost.

Discount vs profit margin

A discount can reduce profit margin if costs stay the same.

Suppose an item costs $60 and normally sells for $100:

• Profit before discount: $40
• Margin before discount: 40%

If the selling price is discounted 20% to $80:

• Profit becomes $20
• Margin becomes 25%

The price fell by 20%, but profit fell by 50%. This is why pricing decisions should consider costs as well as the customer-facing discount.

Use the Profit Margin Calculator to evaluate margin after a price change.

How to calculate a discount in a spreadsheet

If the original price is in cell A2 and the discount percentage is entered as 20% in B2, the final price formula is:

=A2*(1-B2)

If B2 contains the number 20 rather than the percentage value 20%, use:

=A2*(1-B2/100)

The discount amount is:

=A2*B2

when B2 is stored as a percentage.

Always check how the spreadsheet cell is formatted so that 20 and 20% are not confused.

Common discount calculation mistakes

Subtracting the percentage number directly

A 20% discount on $100 is $20, but a 20% discount on $250 is $50. The percentage must be applied to the original price.

Using the sale price as the baseline

When calculating the discount percentage, divide the reduction by the original price, not the sale price.

Adding sequential discounts

Two successive discounts are applied to different price bases, so 20% off followed by 10% off is not the same as 30% off.

Forgetting taxes, fees or shipping

A basic discount calculation usually applies to the stated price before other charges unless the seller specifies otherwise. Check which amount the discount actually applies to.

Confusing markup with margin

Markup is based on cost, while profit margin is based on revenue. A discount can change both, but they require separate calculations.

FAQ

How do I calculate 20% off a price?

Multiply the original price by 0.20 to find the amount saved, then subtract it. Or multiply the original price directly by 0.80 to get the final price.

What is 25% off $80?

The discount is 80 × 0.25 = 20, so the final price is $60.

What percentage discount is $50 off $200?

50 ÷ 200 × 100 = 25%. The discount percentage is 25%.

How do I reverse a discount?

Divide the sale price by the remaining-price factor. For a 20% discount, divide by 0.80. For a 30% discount, divide by 0.70.

Calculate the sale price

Enter the original price and discount percentage in the Discount Calculator to see the final price and discount amount, then use the formulas above when you need to reverse or compare a discount.