Percentage Calculator
How percentages work
Percent means per hundred. To find a percentage of a number, divide the percent by 100 and multiply. For example, 15% of 240 is 0.15 times 240, which equals 36. To find what percent one number is of another, divide the part by the whole and multiply by 100. So 45 out of 180 is 25%.
Common uses
A 30% discount on an $80 item leaves 70% of the price, so you pay $56. Adding 8% sales tax to a $50 purchase brings it to $54. A 3% raise on a $60,000 salary adds $1,800, for $61,800 a year. The increase and decrease results in the calculator handle all of these.
A common mistake
Percent increases and decreases do not cancel out. If a price rises 50% from $100 to $150 and then falls 50%, it lands at $75, not $100. This happens because the second percentage applies to a bigger number.
Frequently asked questions
How do I calculate percent change?
Subtract the old value from the new value, divide by the old value and multiply by 100. A result above zero is an increase, and below zero is a decrease.
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Estimates for education only, not financial advice.