1. What is Percentage Change?

Percentage change measures the relative difference between an old value and a new value, expressed as a percentage. It shows how much a quantity has increased or decreased compared to its original value.

2. How Does the Calculator Work?

The calculator uses the percentage change formula:

Where:

• New Value (n₂) — The updated or current measurement
• Old Value (n₁) — The original or previous measurement
• Absolute value ensures correct calculation when old value is negative

Explanation: The formula calculates the relative change between two numbers, showing the change as a percentage of the original value.

3. Importance of Percentage Change

Details: Percentage change is widely used in finance, economics, science, and data analysis to compare changes over time, assess growth rates, and make relative comparisons between different datasets.

4. Using the Calculator

Tips: Enter both numbers (old and new values). The calculator automatically handles positive and negative values correctly. Note that percentage change from zero is undefined.

5. Frequently Asked Questions (FAQ)

Q1: What does a negative percentage change mean?
A: A negative result indicates a decrease from the original value, while positive indicates an increase.

Q2: How is this different from percentage difference?
A: Percentage change compares two values over time (before/after), while percentage difference compares two distinct values at the same time.

Q3: Why use absolute value in the denominator?
A: The absolute value ensures the percentage change is meaningful when dealing with negative numbers.

Q4: What if my starting value is zero?
A: Percentage change is undefined when starting from zero, as it would require division by zero.

Q5: How do I interpret a 100% change?
A: A 100% increase means the value has doubled. A 100% decrease means the value has gone to zero.