What Is a Discount Percentage Calculator?
A discount percentage calculator tells you how much of a price reduction you are getting when an item is marked down. Instead of guessing whether "$30 off" is a great deal, this tool turns the two numbers you already know — the original price and the sale price — into a clear percentage. It works for any currency, since percentages are unit-free.
How to Use It
Enter the original price (the price before any markdown) and the sale price (what you actually pay). Click calculate and you instantly see the discount percentage, plus the exact amount of money you saved. This is handy for comparing two sales, checking a store's advertised "% off," or budgeting before you buy.
The Formula Explained
The math is simple: subtract the sale price from the original price to find the amount of the discount, divide that by the original price, then multiply by 100 to express it as a percentage.
$$\text{Discount \%} = \frac{\text{Original Price} - \text{Sale Price}}{\text{Original Price}} \times 100$$
Dividing by the original price (not the sale price) is the key step — the discount is always measured relative to what you would have paid at full price.
Worked Example
Suppose a jacket originally costs $120 and is on sale for $90. The amount off is \(120 - 90 = \$30\). The discount percentage is $$\frac{30}{120} \times 100 = 25\%$$ So you are saving 25% and keeping $30 in your pocket.
FAQ
Does this work in any currency? Yes. Percentages and savings are calculated from whatever numbers you enter, so dollars, euros, pounds and others all work the same way.
Why divide by the original price instead of the sale price? A discount is defined relative to the full price you would otherwise pay, so the original price is the correct base.
What if the sale price is higher than the original? The result will be a negative percentage, which means a price increase rather than a discount.
