Q1: How do I calculate percentage increase or decrease?
Percentage change = [(New Value - Old Value) / Old Value] × 100. A positive result indicates an increase, while a negative result indicates a decrease. For example, if a price goes from $100 to $120, that's a 20% increase.
Q2: What does a negative percentage change mean?
A negative percentage change means the value has decreased. For example, if something goes from 100 to 80, the percentage change is -20%, indicating a 20% decrease. The negative sign shows the direction of change.
Q3: Can percentage change be more than 100%?
Yes, percentage change can exceed 100% when the new value is more than double the old value. For example, if something increases from 50 to 150, that's a 200% increase (the value tripled).
Q4: How is percentage change different from percentage points?
Percentage change measures the relative change from one value to another. Percentage points measure the difference between two percentages. For example, going from 10% to 15% is a 5 percentage point increase, but a 50% relative increase.
Q5: What if the old value is zero?
If the old value is zero, you cannot calculate percentage change using the standard formula (division by zero). In such cases, any positive new value represents an infinite percentage increase, which is typically expressed as "N/A" or handled separately.
Q6: How do I interpret percentage change in real-world scenarios?
Percentage change helps compare changes across different scales. A 10% increase on $100 is $10, while a 10% increase on $1,000 is $100. Always consider both the percentage and the actual dollar amounts when making decisions.