The Percentage Calculator solves eight common percentage problems: finding a percentage of a value, finding what percentage one value is of another, measuring percentage change or difference, adding or subtracting a percentage, reversing a percentage, and converting a fraction to a percentage.
Choose the calculation mode
- What is X% of Y?
X / 100 x Y - X is what percent of Y?
X / Y x 100 - Percentage change:
(Y - X) / |X| x 100 - Add a percentage:
X x (1 + Y / 100) - Subtract a percentage:
X x (1 - Y / 100) - Reverse a percentage:
X / (Y / 100) - Percentage difference:
|X - Y| / |(X + Y) / 2| x 100 - Fraction to percentage:
X / Y x 100
The calculator rounds the final numeric result to four decimal places. Intermediate calculations retain normal JavaScript number precision.
Worked examples
For 15% of 240, enter X = 15, Y = 240, and choose the first mode: 0.15 x 240 = 36.
For a change from 80 to 100, choose percentage change: (100 - 80) / 80 x 100 = 25%.
For a fraction of 3/8, choose fraction to percentage: 3 / 8 x 100 = 37.5%. The denominator cannot be zero.
Percentage vs. percentage increase
Use this page for mixed percentage operations. Use the Percentage Increase Calculator when the main task is comparing an original value with a new value, finding the original value, or calculating a change in a price or measurement.
Questions
How do I calculate a percentage of a number?
Convert the percentage to a decimal by dividing by 100, then multiply by the number. For example, 20% of 50 is 0.20 x 50 = 10.
How do I find what percent one number is of another?
Divide the first number by the reference number and multiply by 100. The reference value cannot be zero.
What is the difference between percentage change and percentage difference?
Percentage change uses a defined starting value. Percentage difference compares two values against their average, so it is symmetric when the values are swapped.
Limitations
The calculator performs arithmetic only. It does not infer whether a percentage should be applied before tax, after tax, before rounding, or to a particular accounting base; choose the values and reference base deliberately.