Percent of change, or percent change, is a percent that expresses an amount of change as a percent of the original amount. It is calculated as the ratio of the change in the amount to the original amount. Percent of Change, p % =Amount of Change/Original Amount If the new amount is greater than the original amount, the percent of change is called a percent of increase. Percent of Increase=New Amount -Original Amount/Original Amount If the new amount is less than the original amount, the percent of change is called a percent of decrease. Percent of Decrease=Original Amount-New Amount/Original Amount