Percentage Change Calculator
Calculate the percentage increase or decrease between two numbers instantly, from an old to a new value. No signup. Ideal for prices, statistics, finance and comparisons.
Result
| Percentage change | ||
|---|---|---|
| Difference |
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This percentage change calculator finds the percentage increase or decrease between two numbers, directly in your browser. Enter the old value and the new value, and see the percentage change between them. No account, no install, so you can measure price changes, growth, statistics and comparisons on any device in seconds.
How to Calculate Percentage Change Step by Step
- Enter the old value. Type the original or starting value into the first field. This is the baseline the change is measured from, the before figure.
- Enter the new value. Type the new or final value into the second field. This is the after figure, which the calculator compares against the old value.
- Calculate the change. The tool works out the difference between the two values as a percentage of the old value, giving the percentage change.
- Read increase or decrease. A positive result means an increase, and a negative result means a decrease, showing both the direction and the size of the change.
- Use the result. Apply the percentage change to your analysis, whether tracking a price movement, measuring growth, or comparing figures over time.
What Percentage Change Means
Percentage change measures how much a value has increased or decreased relative to its original amount, expressed as a percentage. It is calculated by taking the difference between the new and old values, dividing by the old value, and expressing the result as a percentage. This relative measure is far more meaningful than the raw difference alone, because it puts the change in proportion to where it started, letting you compare changes of different absolute sizes fairly.
The key to percentage change is that it is always relative to the original value, the old figure, not the new one. This matters because the same absolute change is a different percentage depending on the starting point. An increase of ten from a base of ten is a hundred percent increase, while an increase of ten from a base of a hundred is only ten percent. The old value is the denominator, which is why identifying it correctly is essential.
Percentage change is used everywhere that quantities move over time or differ between situations. Price changes, whether a rise or a discount, are percentage changes. Growth in a business, a population, or an investment is expressed as a percentage change. Statistics comparing before and after, or one period against another, use it constantly. Its universality comes from being the natural way to express how much something has changed in proportional, comparable terms.
A common source of confusion is the difference between percentage change and percentage points, which are not the same. If a rate goes from ten percent to twelve percent, that is an increase of two percentage points, but a twenty percent change relative to the original ten percent. Mixing these up leads to serious misunderstandings, especially in reporting statistics and rates, so it is important to be clear about which one you mean.
Percentage Change Versus Percentage Points
| Old value | New value | Change | Percentage |
|---|---|---|---|
| Increase | New higher than old | Positive | A percentage increase |
| Decrease | New lower than old | Negative | A percentage decrease |
| Same absolute change | Different bases | Same difference | Different percentages |
| Base | Always the old value | The denominator | Determines the percentage |
Who Uses a Percentage Change Calculator
Pro Tips for Percentage Change
Common Percentage Change Mistakes to Avoid
Related Tools You May Need Next
For a percentage of a number, our Percentage of a Number calculator helps, and the Discount Calculator applies a percentage off a price. For profit margins, the Markup Calculator works out markup and margin.
Frequently Asked Questions
How do I calculate percentage change?
Enter the old value and the new value, and the calculator finds the difference between them, divides it by the old value, and expresses the result as a percentage. A positive result is an increase and a negative one is a decrease. This gives you the change in proportional terms, which is more meaningful than the raw difference because it accounts for the starting point, letting you compare changes of different sizes fairly.
What is percentage change?
Percentage change measures how much a value has increased or decreased relative to its original amount, expressed as a percentage. It is the difference between the new and old values, divided by the old value, shown as a percentage. This relative measure is more meaningful than the raw difference alone because it puts the change in proportion to where it started. It is used everywhere quantities move over time, from prices to growth to statistics.
Is percentage change measured from the old or new value?
Always from the old value, the original or starting figure. Percentage change is the difference between the values divided by the old value, so the old value is the denominator, the base. This matters because the same absolute change is a different percentage depending on the starting point: an increase of ten is a hundred percent from a base of ten but only ten percent from a base of a hundred. Using the new value as the base gives the wrong result.
What is the difference between percentage change and percentage points?
They are different and often confused. Percentage points are the raw difference between two percentages: a rate going from ten percent to twelve percent rises by two percentage points. Percentage change is that difference relative to the starting value: from ten percent to twelve percent is a twenty percent change, since two is twenty percent of ten. Mixing these up causes serious misunderstandings, especially when reporting rates and statistics, so be clear which measure you mean.
How do I know if it is an increase or a decrease?
The sign of the result tells you: a positive percentage change means the value increased, since the new value is higher than the old, and a negative percentage change means it decreased, since the new value is lower. The number itself tells you the size of the change. So reading both the sign and the number together gives you the full picture, the direction and the magnitude of the change between the two values.
Why is percentage change better than the raw difference?
Because it accounts for the starting point, letting you compare changes of different absolute sizes fairly. A raw difference of ten means very different things depending on whether it started from ten or from a thousand. Expressing the change as a percentage of the original puts it in proportion, so you can meaningfully compare, for example, the growth of a small figure against a large one. This proportional, comparable quality is why percentage change is so widely used.
Can a percentage change be more than a hundred percent?
Yes. If a value more than doubles, the percentage increase exceeds a hundred percent. For example, going from ten to twenty five is a hundred and fifty percent increase, since the increase of fifteen is a hundred and fifty percent of the original ten. There is no upper limit on a percentage increase. A percentage decrease, however, cannot exceed a hundred percent, since a value cannot decrease by more than its entire amount to below zero in this sense.
Is the percentage change calculator free?
Yes, it is completely free with no account and no usage limit. You can calculate as many percentage changes as you like, as often as you like, at no cost. It runs entirely in your browser on any device, so there is nothing to download or install, and the percentage increase or decrease appears instantly whenever you enter an old value and a new value.