Percentage change tells you how large a movement is relative to where it began. It is useful when you want to compare growth or decline across amounts of different sizes. A €30 change matters differently when the starting value is €60 than when it is €6,000.
The formula
Percentage change = (ending value − starting value) ÷ starting value × 100. If a monthly amount changes from €2,400 to €2,700, the difference is €300. Divide €300 by €2,400 and multiply by 100: the change is 12.5%.
Decrease example
If a price falls from $1,200 to $960, the difference is −$240. Divide −$240 by $1,200 and multiply by 100. The result is −20%, usually described as a 20% decrease.
Percentage points are different
When a rate changes from 2% to 3%, the difference is 1 percentage point. Relative to the original 2%, that is a 50% increase. Both descriptions can be true; they answer different questions. Use percentage points when comparing one rate to another. Use percentage change when comparing a value with its starting value.
Important limitation: a percentage change is undefined when the starting value is zero. When the starting value is negative, a standard percentage can be hard to interpret. In either case, show the actual difference as well and explain the context rather than forcing a percentage.
Use percentages responsibly
For work, school, business, or personal planning, a percentage adds context but does not tell the entire story. Include the two actual values, the time period, and the unit being measured. For tax, investment, or financial decisions, check authoritative sources or a qualified professional rather than treating a calculator result as advice.
Try the percentage-change calculator and read the formula shown under your result.
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