1. What is a Percentage Calculator?

Definition: This calculator computes the percentage of one value relative to another using the standard percentage formula.

Purpose: It helps quickly determine percentages for various applications including statistics, finance, and data analysis.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( a \) — The part value
• \( b \) — The whole or total value
• \( \% \) — The resulting percentage

Explanation: The formula divides the part by the whole and multiplies by 100 to convert the fraction to a percentage.

3. Java Implementation

Code Example:

public class PercentageCalculator {
    public static double calculatePercentage(double a, double b) {
        if (b == 0) {
            throw new IllegalArgumentException("Total value cannot be zero");
        }
        return (a / b) * 100;
    }
    
    public static void main(String[] args) {
        double value = 25.0;
        double total = 200.0;
        double percentage = calculatePercentage(value, total);
        System.out.println("Percentage: " + percentage + "%");
    }
}
                    

4. Using the Calculator

Tips: Enter the part value (a) and the total value (b). The total value must not be zero.

5. Frequently Asked Questions (FAQ)

Q1: What happens if the total value is zero?
A: Division by zero is undefined, so the calculator will not display a result if the total value is zero.

Q2: Can I calculate percentage decrease?
A: Yes, if the part value is less than the original total, the result will be a percentage decrease.

Q3: How precise are the calculations?
A: Results are displayed with 2 decimal places for most practical applications.

Q4: What's the difference between percentage and percentile?
A: Percentage is a ratio expressed as a fraction of 100, while percentile indicates the value below which a percentage of data falls.

Q5: How would I handle negative values?
A: Negative values can represent decreases or losses, but the interpretation depends on your specific use case.