Percentage and Percentage Change Calculator
Calculate a percentage of a number, one number as a share of another, and percentage increase or decrease. See the numerical difference alongside the results.
Enter the figures you want to check
Calculations run only in your browser. Values are neither saved nor sent to us.
Calculation results
Percentage amount of base
Comparison as a share of base
%
Percentage change
%
Difference between values
How are the results calculated?
Percentage amount = base value × percentage ÷ 100.
Share = comparison value ÷ base value × 100.
Change = (comparison − base) ÷ base × 100.
Assumptions and limits
- Compare values with the same unit and period. Negative change means a decrease. Percentage change differs from a percentage-point difference.
- A percentage is undefined when its base is zero. The calculated amounts remain visible.
Understand the idea behind the calculation
Using the tool and understanding your results
Answer everyday percentage questions in one place: a percentage of an amount, one number’s share of another and the change between two values. Enter the base, comparison and requested rate to see the percentage amount, share, change and numerical difference.
How do I calculate a percentage of a number?
Multiply the number by the percentage and divide by 100. For 15% of 200, calculate 200 × 15 ÷ 100 = 30. Enter 200 as the base and 15 as the requested percentage to get the amount.
How do I calculate what percentage one number is of another?
Divide the comparison value by the base value and multiply by 100. A comparison of 250 and a base of 200 gives 125%. This share differs from the percentage increase between the two values.
How do I calculate percentage increase or decrease?
Subtract the old value from the new value, divide by the old value and multiply by 100. Moving from 200 to 250 is a 25% increase; moving from 250 to 200 is a 20% decrease. Enter the old value as the base and the new value as comparison. A zero base makes the percentage undefined.