October 25, 2026 · Everyday
Save money and avoid misleading deals.
Discounts are everywhere — flash sales, holiday promotions, "buy one get one" offers. But not all discounts are what they seem. Some are genuine savings; others are marketing tricks designed to make you spend more.
In this guide, I will explain how to calculate a discount, how to find the final price, and how to spot misleading sales tactics.
To calculate a discount:
Discount Amount = Original Price × (Discount % / 100)
Final Price = Original Price − Discount Amount
For example, a $100 item with a 25% discount: discount = $25, final price = $75.
Some stores offer multiple discounts — like "20% off, then an extra 10% off at checkout." These do not add up to 30%. They stack multiplicatively. Here is how it works:
The total discount is 28%, not 30%. Always calculate each discount separately.
Not every "sale" is a good deal. Watch out for these tactics:
Before buying, check the price history using tools like CamelCamelCamel (for Amazon) or Honey (for general shopping).
Our free Discount Calculator does the math instantly. Enter the original price and discount percentage, and it shows the final price and your savings. It also handles sales tax if you enter it.
Not necessarily. If the original price was inflated, 50% off may still be more than the item is worth. Compare with other retailers.
Apply the discount first, then add sales tax to the discounted price. Our calculator does this automatically if you enter your tax rate.
Doorbuster sales offer deep discounts on a limited number of items to attract customers. Often, only a few units are available, and most shoppers end up buying something else.
Discounts can save you real money — but only if you know how to calculate them and spot fake sales. Use our free Discount Calculator to check the final price before you buy.