Percentage Change Calculator

Calculate the percentage increase or decrease between two values. Perfect for analyzing price changes, growth rates, investment returns, and relative differences.

Calculate Percentage Change

Starting or initial value

Final or current value

Understanding Percentage Change

What is Percentage Change?

Percentage change measures the relative change between two values. It expresses the difference as a percentage of the original value, making it easy to compare changes across different scales. A positive change indicates growth, while negative shows decline.

When to Use Percentage Change

  • • Investments: Track portfolio performance and returns
  • • Business: Analyze sales growth, revenue changes, and KPIs
  • • Economics: Measure inflation, GDP growth, and market trends
  • • Personal Finance: Monitor savings, expenses, and budget changes
  • • Science: Compare experimental results and data variations

Important Considerations

  • • Percentage changes are not symmetric (50% decrease ≠ 50% increase to return)
  • • Cannot calculate percentage change from zero (undefined)
  • • Large percentage changes on small numbers can be misleading
  • • Always consider the absolute values alongside percentages
  • • Compound percentage changes multiply, not add

Common Percentage Changes

+100%
Doubled (2x)
+50%
1.5x increase
-50%
Halved (0.5x)
+200%
Tripled (3x)
+25%
1.25x increase
-75%
Quarter (0.25x)

Pro Tip: When comparing multiple percentage changes over time, use the geometric mean rather than arithmetic mean. For example, if an investment gains 50% one year and loses 30% the next, the average annual return is not 10% but actually about 2.4% (calculated as √(1.5 × 0.7) - 1).

Quick Reference

Percentage Increase
((New - Old) / Old) × 100
Percentage Decrease
((Old - New) / Old) × 100
Growth Multiplier
New Value ÷ Original Value

Common Scenarios

  • Price Changes:Sales, discounts, inflation
  • Growth Rates:Revenue, population, traffic
  • Performance:ROI, efficiency, productivity
  • Comparisons:Year-over-year, benchmarks

Tips & Tricks

  • •Use negative values for losses or decreases
  • •Check both percentage and absolute changes
  • •Consider context when interpreting results
  • •Remember: -50% then +50% ≠ 0% total change
  • •For multiple periods, use compound growth rate

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