1. What is Percentage Change?

Percentage change measures the degree of change over time. It calculates how much a value has increased or decreased relative to its original value, expressed as a percentage. This is useful for comparing changes in quantities of different scales.

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 the new and old values, divides by the old value to get a relative change, then multiplies by 100 to convert to a percentage.

3. Importance of Percentage Change

Details: Percentage change is widely used in finance (stock price changes), economics (inflation rates), business (sales growth), and science (experimental results). It provides a standardized way to compare changes across different scales.

4. Using the Calculator

Tips: Enter both old and new values. The calculator will determine if it's an increase or decrease and display the percentage change. Note: Old value cannot be zero (division by zero is undefined).

5. Frequently Asked Questions (FAQ)

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

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

Q3: What if my old value is zero?
A: Percentage change is undefined when the old value is zero, as division by zero is mathematically impossible.

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

Q5: How do I interpret a percentage decrease?
A: A percentage decrease shows how much a value has reduced relative to its original amount. For example, a 20% decrease means the new value is 80% of the original.