Percent Change Calculator

The percent change formula

Percent change compares the difference between two values to the original value. A positive result indicates an increase; a negative result indicates a decrease. The formula works for any measurable quantity: prices, populations, test scores, revenue, or physical measurements.

For example, if a stock price rises from 40 to 52, the change is (52 - 40) / 40 x 100 = 30%. If it falls from 52 to 40, the change is (40 - 52) / 52 x 100 = -23.08%. Note that the percentage change is not symmetric.

Percent change vs. percentage difference

Percent change uses the original value as the reference point and implies a direction (increase or decrease). Percentage difference uses the average of the two values as the reference and does not imply direction. Use percent change when there is a clear before-and-after relationship, and percentage difference when comparing two values without a time ordering.