Discount Calculator

What This Discount Calculator Does

A discount is a percentage taken off a price. This calculator finds the sale price and how much you save. It can also add sales tax to the discounted price, or apply two discounts one after the other (a “stacked” or “extra % off” deal).

Discount Formula

To take a percentage off a price:

discount = price x (percent / 100)
sale price = price - discount

To add sales tax to the discounted price:

final price = (price - discount) x (1 + tax / 100)

For two discounts applied one after the other:

final price = price x (1 - first / 100) x (1 - second / 100)

How to Calculate a Discount

1. Multiply the price by the percent, divided by 100, to get the amount off.
2. Subtract that amount from the price to get the sale price.
3. To include tax, multiply the sale price by 1 + tax / 100.

Worked Examples

Problem	Steps	Answer
25% off a price of 80	80 x (25 / 100) = 20 off	60
30% off a price of 50	50 x (30 / 100) = 15 off	35
40% off 120, then 8% tax	120 - 48 = 72, then 72 x 1.08	77.76
20% then 10% off 200	200 x 0.8 x 0.9	144 (28% off)

Common Uses

• Working out a sale price before you buy.
• Checking a store’s “extra percent off” stacked deal.
• Adding sales tax to a discounted price.
• Comparing two offers quickly.

FAQ

How do you calculate a discount?

Multiply the price by the percent, divided by 100. For example, 25% off 80 is 80 x (25 / 100) = 20, so the sale price is 80 - 20 = 60.

How do you add sales tax to a discounted price?

Take the price after the discount and multiply by 1 + tax / 100. For 72 after a discount with 8% tax: 72 x 1.08 = 77.76.

Do two stacked discounts add together?

No. 20% off and then 10% off is not 30% off. Each percent applies to a smaller amount, so 200 x 0.8 x 0.9 = 144, which is 28% off overall.

Is the discount math exact?

The math is exact for the numbers you enter. For a real purchase, check the store’s final total, since rounding and local tax rules can vary.