How do I calculate a price after a percentage discount?

Multiply the original price by the discount rate divided by 100, then subtract that amount from the original price. You can also multiply the original price by the percentage that remains.

Why do 20% off and 10% off equal 28% off?

After 20% off, 80% of the original price remains. Reducing that remainder by 10% removes another 8% of the original price, so the combined discount is 28%.

How do I find the original price before a discount?

Divide the sale price by one minus the discount rate as a decimal. For example, a sale price of 72 after 20% off gives 72 divided by 0.80, or an original price of 90.

Can I compare a fixed discount with a percentage offer?

Calculate each offer separately in Sale price mode using the same original price and applicable tax assumptions, then compare the final prices. The dedicated Compare offers mode accepts percentage discounts.

How to Calculate Discounts: Formulas & Examples

Discount formulas at a glance

A discount calculation starts with three values: the original price, the amount saved, and the sale price. If you know any two of those values, plus a percentage rate where needed, you can usually recover the missing value. The Discount Calculator handles the five calculations explained below.

Discount amount = Original price × (Discount rate ÷ 100)

Sale price = Original price − Discount amount

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

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

Treat every price input as being in the same currency. The formulas work for dollars, pounds, euros, rupees, or any other currency; the calculator does not perform currency conversion.

Calculate a sale price and savings

For a percentage discount, first multiply the original price by the percentage written as a decimal. Subtract the result from the original price.

Example: 25% off an original price of 120

Discount amount = 120 × 0.25 = 30
Sale price = 120 − 30 = 90

The pre-tax savings are 30 and the sale price is 90. A fixed-amount offer is simpler: subtract the stated amount directly. For example, 15 off 100 leaves 85.

Find the actual discount rate

When a store shows an original price and sale price but not the percentage, divide the price reduction by the original price.

Example: original price 80, sale price 60

Price reduction = 80 − 60 = 20
Discount rate = 20 ÷ 80 × 100 = 25%

The original price must be greater than zero, and a discount result assumes the sale price is not higher than the original price. For broader reverse-percentage questions, use the reverse percentage calculator.

Recover the original price

A 20% discount leaves 80% of the original price. Divide the known sale price by that remaining proportion.

Example: sale price 72 after 20% off

Remaining proportion = 1 − 0.20 = 0.80
Original price = 72 ÷ 0.80 = 90
Savings = 90 − 72 = 18

This reverse formula requires a discount below 100%. If an item is free after a 100% discount, its sale price is zero regardless of the original price, so the original cannot be recovered uniquely.

Apply sequential percentage discounts

Multiple percentage discounts must be applied in order. Do not add them unless the offer explicitly describes one combined rate. Each later discount applies to the reduced price left by the previous one.

Example: 20% off, then another 10% off

After first discount = 100 × 0.80 = 80
After second discount = 80 × 0.90 = 72
Effective discount = (100 − 72) ÷ 100 × 100 = 28%

The result is 72, not 70. An equivalent one-line formula is 100 × (1 − 0.20) × (1 − 0.10).

Compare two offers on the same price

A larger advertised number is not always enough to compare promotions when one offer contains a second reduction. Use the same original price and tax assumption for both offers.

Example: 25% off versus 20% then 10% off

Offer A = 100 × 0.75 = 75
Offer B = 100 × 0.80 × 0.90 = 72
Difference = 75 − 72 = 3

Offer B has the lower calculated price by 3. This comparison covers price only; shipping, fees, product differences, eligibility, return terms, and coupon restrictions can change the practical choice.

How optional tax is handled

Sale price, stacked discount, and comparison modes can add an optional tax rate after all discounts. For an original price of 100, 20% off, and 8.25% tax:

Discounted subtotal = 100 × 0.80 = 80
Tax = 80 × 0.0825 = 6.60
Final price = 80 + 6.60 = 86.60

This is a calculation assumption, not a statement of tax law. The taxable base can vary by jurisdiction, product, coupon type, and retailer. Confirm the applicable rate and treatment before relying on the final amount. To add or extract a known tax rate directly, see the VAT and Sales Tax Calculator.

Limitations and common mistakes

Do not add sequential percentages; multiply the remaining-price factors.
Compare offers from the same genuine starting price and include unavoidable fees.
Keep savings separate from tax: savings are calculated before the optional tax, while final price includes it.
Check whether a coupon can be combined with an existing sale. The Coupon Savings Guide covers common order and eligibility questions.
Retailers may round at each step. This calculator keeps calculation precision and displays price results to two decimal places, so a checkout total can differ by a minor unit.