How to calculate a percentage
To find a percentage of a number, multiply the number by the percent and divide by 100. For example, 15% of 250 = 250 ร 15 รท 100 = 37.5.
Everyday US uses
The โValue + %โ row is handy for adding sales tax (enter your state/local rate โ most are 4โ10%) or a tip, while โValue โ %โ gives a sale price after a discount. To find what percent one number is of another, divide the part by the whole and multiply by 100 โ e.g. 45 out of 180 is 45 รท 180 ร 100 = 25%.
Percentage change vs percentage points
A jump from 4% to 6% is a rise of 2 percentage points, but a 50% increase in the rate itself. Mixing the two is a common mistake โ percentage points measure the gap between two percentages, while percentage change measures growth relative to the starting value.
Frequently asked questions
Can I use it for discounts?
Yes โ the โValue โ %โ row shows the price after a discount of that percent.
How do I add sales tax?
Enter your combined state and local rate as the percent; the โValue + %โ row gives the after-tax total. Sales tax is set per state and city, so the rate varies by location.
How do I find the original price before a discount?
Divide the sale price by (1 minus the discount as a decimal). A $60 item at 25% off was $60 รท 0.75 = $80 before the discount.