1. What Is Percentage Change?

Percentage change measures the relative difference between an old value and a new value, expressed as a percentage. It's commonly used in finance, economics, science, and everyday life to track growth or decline.

2. How The Calculation Works

The percentage change formula is:

Key points:

• Positive result indicates an increase
• Negative result indicates a decrease
• The old value cannot be zero (division by zero)
• Expressed as a percentage (%)

3. Practical Applications

Common uses: Tracking stock prices, measuring population growth, calculating inflation rates, analyzing test score improvements, comparing sales figures, and monitoring weight changes.

4. Using The Calculator

Instructions: Enter the original (old) value and the new value. The calculator will compute the percentage change between them. Values can be positive or negative (except old value cannot be zero).

5. Frequently Asked Questions (FAQ)

Q1: What if my old value is zero?
A: Percentage change is undefined when the old value is zero since it would require division by zero.

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

Q3: Can percentage change be more than 100%?
A: Yes, when the new value is more than double the old value, the percentage change exceeds 100%.

Q4: What does a negative percentage change mean?
A: A negative percentage change indicates a decrease from the old value to the new value.

Q5: How do I interpret a percentage change from 50 to 75?
A: This would be a 50% increase (75-50=25, 25/50=0.5, 0.5×100=50%).