Percentage Change Calculator
Calculate percentage increase and decrease with step-by-step solutions
How to Use This Calculator
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The Percentage Change Calculator helps you find the percentage increase or decrease between two values. This is useful for comparing prices, grades, statistics, and more.
Formula
Percentage Change = ((New Value - Original Value) / Original Value) × 100
- Positive result = percentage increase
- Negative result = percentage decrease
- Zero = no change
Example Problems
Grade Improvement:
Your test score improved from 75 to 90 points.
Result: +20% increase
Stock Price Change:
A stock went from $100 to $115.
Result: +15% increase
Population Decline:
Population decreased from 10,000 to 8,500.
Result: -15% decrease
Temperature Change:
Temperature rose from 20°C to 25°C.
Result: +25% increase
Sales Growth:
Monthly sales increased from $5,000 to $6,500.
Result: +30% increase
Understanding the Concept
Percentage change shows the relative difference between two values as a percentage of the original value. This makes it easier to compare changes of different magnitudes.
For example, an increase from 100 to 110 is a 10% increase, and an increase from 1000 to 1100 is also a 10% increase, even though the absolute change is different (10 vs 100).
Frequently Asked Questions
How do I calculate percentage increase?
To calculate percentage increase, subtract the original value from the new value, divide by the original value, and multiply by 100. For example: ((230 - 200) / 200) × 100 = 15% increase.
How do I calculate percentage decrease?
Percentage decrease uses the same formula. The result will be negative. For example: ((170 - 200) / 200) × 100 = -15% (which is a 15% decrease).
What's the difference between percentage change and percentage point change?
Percentage change is relative to the original value (e.g., 50% to 75% is a 50% increase). Percentage point change is the absolute difference (e.g., 50% to 75% is a 25 percentage point increase). This calculator computes percentage change, not percentage points.
Can percentage change be negative?
Yes! A negative percentage change indicates a decrease. For example, -20% means the value decreased by 20%. Some people prefer to say "20% decrease" instead of "-20% change" to avoid negative signs.
How do I calculate percentage change in Excel?
In Excel, use the formula: =((B1-A1)/A1)*100 where A1 is the original value and B1 is the new value. Format the cell as a number or add "%" to display as a percentage.
Why can't I use zero as the original value?
Percentage change requires dividing by the original value. Since division by zero is undefined in mathematics, you cannot calculate percentage change when the original value is zero. Use absolute difference instead.
Why use a percentage change calculator?
A percentage change calculator saves time, prevents calculation errors, and shows step-by-step work for learning. It's perfect for homework, comparing statistics, analyzing financial data, or any situation where you need to understand how much something has changed relative to its original value.
What are real-world uses of percentage change?
Percentage change is used everywhere: tracking stock market changes, analyzing sales growth, comparing test scores, measuring economic indicators (GDP, unemployment), evaluating inflation rates, monitoring website traffic changes, and comparing scientific measurements.
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Educational Disclaimer
This calculator is provided for educational purposes and homework assistance. While we strive for accuracy, please verify critical calculations independently. Results should not be used as the sole basis for important financial, academic, or professional decisions. Always check your work and consult with appropriate professionals when needed.