Percentage Calculator
20% of 150 is 30. 30 is 20% of 150. Going from 80 to 100 is a 25% increase.
How to use
- Pick the question you have: "What is X% of Y", "X is what % of Y", or "Percent change".
- Type the two numbers. The result updates as you type.
- Use Copy result to paste the answer, or Share link to send the same calculation to someone.
How it works
X% of Y = X ÷ 100 × Y. For example 20% of 150 = 20 ÷ 100 × 150 = 30.
X is what percent of Y = X ÷ Y × 100. For example 30 is 30 ÷ 150 × 100 = 20% of 150.
Percent change = (new value − old value) ÷ |old value| × 100. A positive result is an increase and a negative result is a decrease. The old value is the starting point, so it cannot be zero.
FAQ
How do I calculate a percentage increase?
Choose Percent change, enter the starting value as From and the final value as To. Going from 80 to 100 gives +25%, because the rise of 20 is a quarter of 80.
Why is a 50% increase followed by a 50% decrease not back to the start?
The second percentage is taken from a bigger number. 100 up 50% is 150, and 150 down 50% is 75, not 100. To undo a +50% change you need a decrease of 33.3%.
What is the difference between percent and percentage points?
If a rate moves from 10% to 12%, it rose by 2 percentage points, which is a 20% relative increase. Use Percent change for the relative figure and plain subtraction for points.
Can a percentage be more than 100?
Yes. 150% of 40 is 60, and going from 20 to 80 is a 300% increase. A decrease cannot go below −100%, because that would mean falling past zero.