Calculate Percentage Increase or Decrease
Instantly find the percentage change between two numbers. Perfect for tracking grade improvements, price changes, or growth over time.
Calculation
Quick Tips
- Growth Tracking
Use this to see exactly how much your grades have improved since the midterm.
- Sign Matters
If the resulting percentage is negative, it represents a percentage decrease rather than an increase.
- Baseline
The "Old" value is always your baseline. Reversing Old and New will give a different percentage.
- Absolute Limits
Going from 0 to any positive number is a 100% increase in this simplified calculation.
How to Use This Tool
- 1
Enter your original or starting value (Old Value).
- 2
Enter your current or ending value (New Value).
- 3
The calculator will instantly show the percentage difference and tell you if it is an increase or decrease.
The Mathematics
Percent Change = ((New - Old) / |Old|) × 100Subtract the old value from the new value, divide the result by the absolute value of the old value, and multiply by 100. A positive result is an increase; a negative result is a decrease.
Frequently Asked Questions
What is the difference between percentage change and percentage difference?
Percentage change compares an old value to a new value over time. Percentage difference (using the other calculator) compares two different things at the same time against their average.
Can a percentage increase be more than 100%?
Yes! If a value more than doubles, the increase is greater than 100%. For example, going from 50 to 150 is a 200% increase.
Why is a 50% decrease followed by a 50% increase not the original number?
Because the baseline changes. A 50% decrease from 100 is 50. A 50% increase from 50 is 75, not 100. You would need a 100% increase to return to the original 100.
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