1. What is Percentage Change?

Percentage change measures the degree of change over time and is used to compare the relative change between an old value and a new value. It expresses the change as a percentage of the original value.

2. How Does the Calculator Work?

The calculator uses the percentage change formula:

Where:

• New Value — The current or ending value
• Old Value — The original or starting 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, economics, statistics, and many scientific fields to measure growth rates, price changes, performance improvements, and other comparative metrics.

4. Using the Calculator

Tips: Enter both old and new values. The calculator will show the percentage increase or decrease. Note that the 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 indicates a decrease from the old value to the new value.

Q2: How is percentage change different from percentage difference?
A: Percentage change compares a new value to an old value, while percentage difference compares any two values without reference to which is newer.

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

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

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