Percentage Calculator
Calculate percentages quickly and accurately. Find a percentage of a number, determine what percentage one number is of another, calculate percentage increase or decrease, compare two values, and add or subtract a percentage.
What Is X% of Y?
Find a percentage of any number. For example, calculate 15% of 240.
X Is What Percent of Y?
Determine what percentage one number represents of another number.
Percentage Increase or Decrease
Calculate the percentage change between an original value and a new value. Negative values are supported.
Percentage Difference
Compare two values using percentage difference, where neither value is treated as the original.
Add or Subtract a Percentage
Increase or decrease a number by a specified percentage.
Percentage Formulas
Percentage of a Number
To calculate X percent of Y, divide X by 100 and multiply the result by Y.
What Percentage Is X of Y?
Divide the part by the whole and multiply by 100.
Percentage Change
Percentage change compares a new value with an original value.
Percentage Difference
Percentage difference compares two values without treating either value as the starting point.
How to Calculate Percentages
A percentage expresses a number as a fraction of 100. The word "percent" means "per hundred." Percentages are used in mathematics, finance, statistics, shopping, education, business, and everyday calculations.
Example: What Is 20% of 150?
Convert 20% to a decimal by dividing it by 100:
Then multiply by 150:
Therefore, 20% of 150 is 30.
How to Calculate Percentage Increase
Suppose a value increases from 80 to 100. First calculate the change:
Divide the change by the original value and multiply by 100:
The value increased by 25%.
How to Calculate Percentage Decrease
If a value falls from 100 to 75, the decrease is 25. Relative to the original value of 100, the percentage decrease is 25%.
Percentages With Negative Numbers
Percentages can also be calculated using negative numbers. For example, the calculator can calculate 20% of −150:
For percentage change, the calculator uses the absolute value of the original number as the reference magnitude. This is useful when the original value itself is negative because it prevents the sign of the original number from producing an unintuitive reversal in the displayed percentage.
Common Uses of Percentages
- Discounts and sale prices
- Taxes and fees
- Interest rates
- Exam and test scores
- Statistics and probability
- Business growth and revenue changes
- Population changes
- Financial calculations
- Data analysis
- Comparing quantities
Percentage Calculator FAQ
How do I calculate a percentage of a number?
Divide the percentage by 100 and multiply it by the number. For example, 20% of 150 is (20 ÷ 100) × 150 = 30.
How do I calculate what percentage one number is of another?
Divide the part by the whole and multiply by 100. For example, 25 is 20% of 125 because (25 ÷ 125) × 100 = 20%.
How do I calculate percentage increase?
Subtract the original value from the new value, divide the difference by the absolute value of the original value, and multiply by 100.
How do I calculate percentage decrease?
Subtract the new value from the original value, divide the result by the absolute value of the original value, and multiply by 100.
What is the difference between percentage change and percentage difference?
Percentage change uses an original value as the reference. Percentage difference compares two values using their average magnitude, so neither value is treated as the starting point.
Can a percentage be greater than 100%?
Yes. A percentage can be greater than 100%. For example, 150 is 150% of 100.
Can I calculate percentages using negative numbers?
Yes. This calculator accepts negative numbers. For example, 20% of -150 is -30. Percentage change also supports negative starting and ending values.
What happens if the original value is zero?
Percentage change cannot be calculated when the original value is zero because the percentage-change formula would require division by zero.