Discount Calculator

Retailers often advertise massive sales with phrasing like: "Take 50% off, plus an additional 20% off at checkout!"

It is incredibly easy for consumers to assume this means they are getting a 70% discount total. But this is a mathematical illusion intentionally designed to sound better than it actually is.

Discounts are almost never additive (50% + 20% = 70%). They are multiplicative. The second discount only applies to the already reduced price.

Let's look at a $100 item:

1. First discount (50%): The price drops to $50.
2. Second discount (20%): This takes 20% off the $50 (which is only $10), bringing the final price to $40.

Your final price is $40, which means your total effective discount is 60%, not 70%. This trick allows retailers to advertise massive sounding percentages while protecting their profit margins.

To calculate the true discount of any stacked sale without doing step-by-step math, you can simply multiply the remaining percentages together:

Final Price = Original Price * (1 - Discount 1) * (1 - Discount 2)

$100 * (0.50) * (0.80) = $40