Percentage calculator
Three common percentage calculations, with the formula displayed beside the result.
How to use this tool
Choose a percentage of a number, a part as a percentage of a whole, or percentage change.
Enter the two values. Percentage change requires a positive starting value; a whole of zero is not allowed.
Calculate and check the displayed formula. The result is rounded to 12 significant digits.
What the result means
For a percentage of a number, divide the percentage by 100 and multiply by the number. For a part of a whole, divide the part by the whole and multiply by 100. For change, subtract the starting value from the new value, divide by the starting value, and multiply by 100. A negative change means a decrease.
Questions about this tool
What is the difference between percent and percentage points?
A move from 10% to 15% is an increase of 5 percentage points, but a relative increase of 50%. Choose the calculation that matches your question.
Why can I not use zero as the starting value?
Relative change divides by the starting value, and division by zero is undefined. This tool requires a positive starting value for percentage change.