Three questions, three answers
Percentage calculator
All three classic percentage problems, answered live as you type.
What is X% of Y?
X is what percent of Y?
Percentage change from X to Y
How the math works
X% of Y is X ÷ 100 × Y. To find what percent X is of Y, compute X ÷ Y × 100. Percentage change from X to Y is (Y − X) ÷ X × 100 — positive means an increase, negative a decrease.
Worked examples
What is 25% of 80? 25 ÷ 100 × 80 = 20. This is the form to use for discounts, tax, and tips.
45 is what percent of 150? 45 ÷ 150 × 100 = 30%. Use this to turn a score or share into a percentage.
From 120 to 90? (90 − 120) ÷ 120 × 100 = a 25% decrease. Percentage change always compares against the starting value.
Frequently asked questions
How do I calculate a percentage of a number?
Divide the percentage by 100 and multiply by the number. For example, 15% of 240 is 15 ÷ 100 × 240 = 36.
How do I find a percentage increase or decrease?
Subtract the starting value from the ending value, divide by the starting value, and multiply by 100. A positive result is an increase; a negative result is a decrease.
What is the difference between percent and percentage points?
Moving from 10% to 15% is a rise of 5 percentage points, but a 50 percent increase relative to the starting 10%. Percent compares to the starting value; points compare the raw difference.