1. What is Percentage Change?

Percentage change measures the degree of change over time, expressed as a percentage. It's used to compare how much a quantity has increased or decreased relative to its original value.

2. How Does the Calculator Work?

The calculator uses the percentage change formula:

Where:

• New Value — The current or final value
• Old Value — The original or initial value

Explanation: The formula calculates the difference between new and old values, divides by the old value to get relative change, then multiplies by 100 to convert to percentage.

3. Importance of Percentage Change

Details: Percentage change is widely used in finance, economics, statistics, and science to measure growth rates, price changes, performance improvements, and other comparative metrics.

4. Using the Calculator

Tips: Enter both old and new values. The old value must be greater than zero. The calculator will show percentage increase (positive) or decrease (negative).

5. Frequently Asked Questions (FAQ)

Q1: What does a negative percentage change mean?
A: A negative percentage indicates a decrease from the old value to the new value.

Q2: What if the old value is zero?
A: The calculation is undefined when old value is zero, as division by zero is impossible.

Q3: How is percentage change different from percentage points?
A: Percentage change measures relative change from an original value, while percentage points measure absolute difference between two percentages.

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 do I interpret a percentage decrease?
A: A 20% decrease means the new value is 80% of the original (100% - 20% = 80%).