1. What is Percentage Change?

Percentage change measures the degree of change over time. It's used to compare an old value to a new value, expressing the difference as a percentage of the old value. Positive values indicate increase, negative values indicate decrease.

2. How Does the Calculator Work?

The calculator uses the percentage change formula:

Key points:

• The result is positive when new value > old value (increase)
• The result is negative when new value < old value (decrease)
• The old value cannot be zero (division by zero is undefined)

3. Practical Applications

Common uses: Calculating price changes, stock market performance, population growth rates, test score improvements, sales growth, and any situation where relative change matters more than absolute change.

4. Using the Calculator

Instructions: Enter the original (old) value and the new value. The calculator will show the percentage change and indicate whether it's an increase or decrease.

Example: If a product price changes from $50 to $75, the calculator will show "50% increase".

5. Frequently Asked Questions (FAQ)

Q1: What if the old value is zero?
A: Percentage change is undefined when the old value is zero, as it would require division by zero.

Q2: How is percentage decrease different from percentage increase?
A: The calculation is the same - the sign of the result indicates whether it's an increase (positive) or decrease (negative).

Q3: Why use percentage change instead of absolute change?
A: Percentage change provides context relative to the original size, making comparisons more meaningful.

Q4: Can percentage change be more than 100%?
A: Yes, when the new value is more than double the old value, the percentage change exceeds 100%.

Q5: How to interpret a negative percentage change?
A: A negative percentage change indicates a decrease from the original value.