1. What is a Percentage Change Calculator?

Definition: This calculator measures the percentage increase or decrease between two values.

Purpose: It helps analyze changes in prices, quantities, measurements, or any numerical data over time.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• New — The current or recent value
• Old — The original or previous value

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

3. Interpretation of Results

Positive Result: Indicates an increase (e.g., 15% means 15% increase from old value).
Negative Result: Indicates a decrease (e.g., -8% means 8% decrease from old 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 new to old, while percentage difference compares any two values without directionality.

Q2: How do I interpret a 100% increase?
A: A 100% increase means the new value is double the old value (100% of the original added to itself).

Q3: What does a negative percentage change mean?
A: A negative result indicates a decrease from the old value to the new value.

Q4: Can I calculate percentage change when old value is zero?
A: No, the formula requires division by the old value, so it must be non-zero.

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