Understanding Percentage Change
Percentage change tells you how much a value has increased or decreased relative to its starting point. It's one of the most useful metrics in finance.
What is Percentage Change?
Percentage change measures the relative difference between two values. It answers: "By what percent did this value go up or down?" Unlike absolute change (e.g., +$25), percentage change puts the move in context. A $25 gain on a $100 stock is very different from a $25 gain on a $10,000 stock.
The Formula
The formula is: ((new value − old value) / old value) × 100. If the result is positive, the value increased; if negative, it decreased.
📊 Use our Percentage Change Calculator to compute it instantly.
Common Uses
- Stock returns — "My portfolio is up 12% this year"
- Price changes — "Gas went up 8% last month"
- Growth metrics — Revenue, user count, or market share
- GDP and economic data — Year-over-year comparisons
Watch Out For
If the old value is zero, the formula breaks (division by zero). Also, percentage change can be misleading when values are small or when comparing across very different scales.
For informational purposes only. Not financial advice.