Percentage Change Calculator
Calculate the percentage increase or decrease between two numbers.
Enter the initial (old) value and the final (new) value to find the percentage change between them. Negative numbers and decimals are allowed.
The Percentage Change Formula
Percentage change measures how much a value has grown or shrunk relative to its starting point, expressed as a percentage. The formula is:
Percentage Change = ((New − Old) / |Old|) × 100
For example, if a value goes from 50 to 60, the change is ((60 − 50) / 50) × 100 = 20%. The absolute difference is simply New − Old, which equals 10 in this case.
Increase vs. Decrease
A positive percentage change means the value went up — an increase. A negative percentage change means the value went down — a decrease. A result of 0% means there was no change at all.
- From 80 to 100 is a 25% increase.
- From 100 to 80 is a 20% decrease.
- From 40 to 40 is a 0% change (no change).
Percentage Change vs. Percentage Points
These two concepts are often confused. A percentage point is the simple arithmetic difference between two percentages, while a percentage change is the relative change between them.
For example, if an interest rate rises from 5% to 6%, that is an increase of 1 percentage point, but a 20% percentage change (because 1 is 20% of 5). Always check whether a figure refers to percentage points or a percentage change.
Related Calculators
Note: This calculator provides mathematical calculations for percentage change based on the formula described. Results are accurate to two decimal places. While we strive for accuracy, please verify important calculations independently. This tool is for educational and informational purposes and should not be the sole basis for financial, academic, or professional decisions.