To calculate year-over-year percentage change, or YOY value, evaluate the outcome of two or more measured events and compare them with similar events from another time period. The difference between the specified time periods has to be in years. Use multiple readings to achieve a more accurate percentage change.Continue Reading
Figure out what parameter you want to use to calculate the year-over-year percentage change. Usually, items such as employment figures, dividends received and interest accrued are taken into consideration. For business purposes, revenues, profits and expansion rates can also be important parameters.
Compile entity data for the selected parameter. Separate the current year’s figures from the previous year’s figures for the item under consideration to compare them in the context of percentage change.
Calculate the annual difference by subtracting the previous year's value from the current year's value. Divide the annual difference by the previous year's value to get a comparison. Then multiply this number by 100 to obtain year-over-year percentage change. This can also be written as ( (current value-previous value) / previous value x 100). Use multiple figures from the specified time period to obtain a better estimate of the percentage change.