Discount Calculator

Enter a price and a discount to see the sale price and how much you save. The discount calculator also handles a second stacked discount and sales tax.

Updated
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Applied to the already reduced price

Final price
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How to use the Discount Calculator

  1. Enter the Original price.
  2. Choose a percentage or a fixed amount for Discount 1 and enter it. Press Add another discount for a stacked deal, and fill in Sales tax % if tax applies.
  3. Press Calculate. The final price comes first, then your savings, the effective total discount, and the tax.

How it works

p1 = price × (1 − d1 ÷ 100)      or  price − d1 for a fixed amount
p2 = p1 × (1 − d2 ÷ 100)         or  p1 − d2 for a fixed amount
final = p2 × (1 + tax ÷ 100)
effective % = (price − p2) ÷ price × 100
  • price: the original price
  • d1, d2: the first and second discounts. With no second discount, p2 equals p1.
  • tax: the sales tax rate, applied after the discounts
  • effective %: the single discount that would give the same price before tax

Examples

  • 120 with 25% off = 90.00. You save 30.00.
  • 200 with 20% off, then another 10% off = 144.00. The effective discount is 28%, not 30%. With 8% tax added, the final price is 155.52.

Percentage off or a fixed amount off?

Shops advertise discounts in two ways. A percentage discount, such as 25% off, saves more on expensive items. A fixed discount, such as 20 off, is worth the same on anything above that price.

On a price of 60, 25% off saves 15, so the fixed 20 off is better. On a price of 120, 25% off saves 30 and beats it. The two break even where 25% of the price equals 20: at a price of 80.

Stacked discounts

"An extra 10% off sale prices" is taken from the already-reduced price, not added to the first discount. The calculator applies the second discount in the same way and shows the effective total, so you see the real saving.

Limitations

  • A fixed discount larger than the price gives an error: "Discount can't exceed the price".
  • A percentage discount over 100 gives an error.
  • Tax is always added after the discounts. Places that tax the original price need a different calculation.
  • The currency symbol is for display only. No currency conversion is done.

Frequently asked questions

How do I calculate a discount?

Multiply the price by the discount percentage divided by 100 to get the saving, then subtract it from the price.

How do stacked discounts work?

The second discount applies to the already-reduced price, so 20% plus 10% gives 28% off in total, not 30%.

Is sales tax added before or after the discount?

In most places tax is charged on the discounted price, and that is how this calculator works.

Often used together with the Discount Calculator.