Three quick percentage tools in one: find a percent of a number, find what percent one number is of another, and calculate the percent increase or decrease between two values.
Result
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X is this percent of Y
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Percent change
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How It Works
What is X% of Y: multiply Y by X and divide by 100. For example, 15% of 200 is 200 × 15 / 100 = 30.
X is what percent of Y: divide X by Y and multiply by 100. For example, 30 is 30 / 200 × 100 = 15% of 200.
Percent change between two values: subtract the old value from the new value, divide by the old value, and multiply by 100. A positive result is an increase and a negative result is a decrease.
Worked example: a shirt priced at $80 is marked down 25%. The discount is 80 × 25 / 100 = $20, so the sale price is $60. If it then rises from $60 back to $80, the percent change is (80 − 60) / 60 × 100 = 33.3% increase.
Frequently Asked Questions
Which mode should I use for a discount?
Use "what is X% of Y" with the original price as Y and the discount percentage as X to get the discount amount. Subtract it from the original to get the sale price, or use the discount calculator.
Why does percent change need an old value that is not zero?
Percent change divides by the old value, so a starting value of zero makes the percentage undefined. Use the absolute change instead when the starting value is zero.
Can the result be more than 100%?
Yes. If the part is larger than the whole, or if the new value is more than double the old value, the percentage will exceed 100%.
How is percent change different from percentage-point change?
Percent change measures the relative shift between two numbers, while percentage points measure the absolute difference between two percentages. Going from 10% to 15% is a 5-percentage-point increase but a 50% relative change.
How do I calculate a tip or tax with percentages?
Multiply the bill or pre-tax amount by the percentage divided by 100. A 7.5% sales tax on a $40 meal is 40 × 7.5 / 100 = $3, for a total of $43.
What is the difference between percent off and percent of original?
Percent off tells you the discount amount; the sale price is the original minus that. Percent of original tells you what fraction of the original price you still pay — 75% of original means a 25% discount.