Percentage change shows how much a number increased or decreased compared with its starting value. It is useful for prices, grades, salary raises, investment growth, tax changes, and business reports.
For quick results, use the Percentage Calculator. Enter the old value and the new value to see the percentage increase or decrease instantly.
Percentage change formula
The formula is: ((new value – old value) / old value) x 100. If the result is positive, it is an increase. If the result is negative, it is a decrease.
Example: price increase
If a product rises from $80 to $100, the increase is $20. Divide $20 by the old price of $80, then multiply by 100. The result is a 25% increase.
Example: grade decrease
If a score drops from 90 to 81, the change is -9. Divide -9 by 90 and multiply by 100. The result is a 10% decrease.
Students may also find the Grade Calculator and GPA Calculator useful when converting assignment scores into final grades.
FAQ
Can percentage change be more than 100%?
Yes. If a value more than doubles, the percentage increase is greater than 100%.
Why use the old value in the formula?
The old value is the baseline. Percentage change measures the change compared with where you started.