Icon Calculate My Percentage

How to Use the Calculator

This calculator helps you perform various percentage and per mille calculations. Here’s how to use it:

1. Select Calculation Mode:

Choose between Percent (%) and Per Mille (‰) using the radio buttons at the top. The symbol shown in the input fields and results will update accordingly. Switching modes will clear any current results and errors.

2. Choose a Calculation Type:

The calculator is divided into sections for different types of calculations:

  • What is [value]% of [base]? (Calculates a percentage/per mille of a number)
  • [part] is what % of [whole]? (Calculates what percentage/per mille one number is of another)
  • [part] is [value]% of what? (Calculates the whole when a part and percentage/per mille are known)
  • Increase/Decrease [base] by [change]% (Calculates the result of increasing or decreasing a base value by a percentage/per mille)
    • Use the Increase/Decrease toggle buttons within this section to select the desired operation. Changing this toggle clears the result for this calculation.
  • Percentage Change from [initial] to [final] (Calculates the percentage/per mille change between two numbers)
  • Percentage Difference between [value X] and [value Y] (Calculates the relative difference between two numbers as a percentage/per mille of their average)

3. Enter Your Values:

  • Input your numbers into the corresponding fields for the calculation you want to perform. Placeholder text indicates what value is expected (e.g., "base", "part", "initial").
  • You can use decimals (using either '.' or ',' as the separator).
  • Calculations update automatically as you type valid numbers.

4. View Results:

  • The result for each calculation appears in the "Result" field on the same line.
  • For Percentage Change, the result will indicate if it's an increase (green text) or decrease (red text). A result of "0" indicates no change.
  • For Percentage Difference, if the average of the two numbers is zero but the numbers themselves are different, the result is "Undefined". If both numbers are zero, the result is "0".
  • A copy button appears next to valid results, allowing you to easily copy the calculated value.

5. Error Handling:

  • If you enter invalid input (e.g., non-numeric characters), the input field border will turn red.
  • If a calculation cannot be performed (e.g., division by zero, missing input), an error message will appear below the input fields for that calculation line. Examples include "Cannot divide by zero" or "Please fill in all required fields".
  • Entering valid input or switching modes will clear previous errors.