Percentage Calculator
Free percentage calculator: find X% of a number, work out what percent one value is of another, and calculate percent increase or decrease with the formula shown.
How to Use
- Percent of a value
On the first tab enter a value and a percentage, e.g. 15% of 200, and get 30.
- Ratio
On the second tab enter the part and the whole to see what percentage the part represents.
- Percent change
On the third tab enter the old and new values to get the percent change, the absolute difference and the growth multiple.
FAQ
How do I calculate a percentage of a number?
Multiply the number by the percentage and divide by 100. For example, 15% of 200 is 200 × 15 ÷ 100 = 30.
How do I calculate what percent one value is of another?
Percentage = part ÷ whole × 100%. For example, 30 out of 200 is 15%.
How do I calculate percent change?
Percent change = (new − old) ÷ |old| × 100%. A positive result is an increase and a negative one a decrease. Using the absolute value of the original avoids a sign flip when the starting value is negative.
Why does my percent change differ?
Usually the denominator is wrong. Percent change always divides by the value before the change. Going from 100 to 125 is +25%, but going back from 125 to 100 is −20%.