1. What is Percentage Change?

Definition: Percentage change measures the degree of change over time, expressed as a percentage of the original value.

Purpose: It's commonly used in finance, economics, statistics, and business to compare changes in values over time.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• New Value — The current or ending value
• Old Value — The original or starting value

Explanation: The difference between new and old values is divided by the old value, then multiplied by 100 to convert to a percentage.

3. Interpreting Results

Positive Result: Indicates an increase from the old value to the new value.

Negative Result: Indicates a decrease from the old value to the new value.

4. Using the Calculator

Tips: Enter both old and new values. The old value cannot be zero (division by zero is undefined).

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 result means the new value is less than the old value (a decrease).

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

Q4: What are common applications of percentage change?
A: Stock price changes, sales growth, population changes, inflation rates, and performance metrics.

Q5: How do I calculate percentage increase vs decrease?
A: The same formula works for both - the sign of the result indicates increase (positive) or decrease (negative).