Discount Calculator: Sale Price and Percent Off

About the Discount Calculator

The Discount Calculator tells you what you will actually pay in a sale and how much you save. Enter the original price and a discount, either as a percentage such as 25 percent off or as a fixed amount such as 15.00 off, and the sale price appears straight away. You can stack a second discount on top of the first, add sales tax, and see a table of the price at the most common discounts. Two more modes answer the other everyday questions: what percentage off a price tag really is, and what an item cost before it was reduced.

Every amount is worked out in whole cents, so the result never shows floating point noise such as 47.999999. When a percentage leaves half a cent, the calculator rounds it up, which is how most tills round. The figures show with two decimals and no currency symbol, so the tool works with dollars, euros, pounds or any other currency.

How to use it

The formulas

With an original price $P$ and a discount rate $d$ written as a decimal, the sale price is

$$S = P \times (1 - d)$$

Two discounts $d_1$ and $d_2$ in a row do not add up. The second one is taken off the price that is already reduced:

$$S = P \times (1 - d_1) \times (1 - d_2), \qquad d_{\text{total}} = 1 - (1 - d_1)(1 - d_2)$$

The percent off between an original price $P$ and a sale price $S$, and the original price from a sale price, are

$$\text{percent off} = \frac{P - S}{P} \times 100, \qquad P = \frac{S}{1 - d}$$

Sales tax at rate $t$ is added after all the discounts: $\text{final} = S \times (1 + t)$.

Worked examples

• How much is 20% off 60? The saving is $60 \times 0.20 = 12$, so the sale price is 48.00.
• 20% off, then another 10% off 100. The first discount brings the price to 80.00 and the second takes 8.00 more, for 72.00. The combined discount is 28 percent, not 30 percent.
• What percent off is 60 from 80? The saving is 20.00, and $20 \div 80 = 0.25$, so it is 25 percent off.
• Original price of a 45.00 item at 25% off. $45 \div 0.75 = 60$, so it cost 60.00 before the sale.
• Tax after the discount. 10 percent off 50.00 is 45.00, and 8 percent sales tax on that is 3.60, for a final price of 48.60.

Tips for shopping

Compare stacked offers by their combined percentage, not by adding the numbers on the sign. A fixed amount off is worth more on cheap items and less on expensive ones, so convert it to a percentage to compare it with a percentage offer. To compare the price of different pack sizes, use the Unit Price Calculator. For other percentage questions, such as a percent change or a markup, use the Percentage Calculator, and when the bill comes at a restaurant, the Tip Calculator splits it.

Privacy

Nothing is uploaded; every calculation runs in your browser and never leaves your device. The prices you type stay on this page and are gone when you close or reload it.

Frequently asked questions