1. What Is Percentage Change?

Percentage change measures the relative difference between an old value and a new value, expressed as a percentage. It's widely used in finance, economics, science, and everyday life to track growth or decline.

2. How The Calculation Works

The percentage change formula is:

Key points:

• Positive result indicates an increase
• Negative result indicates a decrease
• Zero means no change
• Division by zero is undefined (old value cannot be zero)

3. Practical Applications

Common uses: Stock price changes, inflation rates, population growth, test score improvements, sales performance metrics, and scientific measurements.

4. Using The Calculator

Instructions: Enter the original (old) value and the new value. The calculator will compute the percentage difference between them.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between percentage change and percentage difference?
A: Percentage change compares a new value to an old value, while percentage difference compares any two values without directionality.

Q2: How do I interpret a negative percentage change?
A: A negative percentage change indicates a decrease from the old value to the new value.

Q3: Why can't the old value be zero?
A: Division by zero is mathematically undefined. When the old value is zero, percentage change cannot be calculated.

Q4: What if both values are negative?
A: The formula still works - it will show the relative change between the two negative numbers.

Q5: How is this different from percentage points?
A: Percentage points measure absolute difference between percentages, while percentage change measures relative difference between values.