Credit:Peter MacdiarmidGetty Images NewsGetty Images
Q:

# How do you calculate year-over-year percent change?

A:

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.

Know More

1. Determine parameters

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.

2. Discover periodic figures

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.

3. Calculate year-over-year 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.

## Related Questions

• A:

Percent elongation quantifies the ability of an element or compound to stretch up to its breaking point. It is measured by dividing the change in length (up to the breaking point) by the original length, then multiplying by 100. Materials with a higher percentage elongation can stretch more before breaking.

• A:

A \$35 item that is marked 40 percent off has a final cost of \$21. The markdown is calculated on its own before it is subtracted from the original price to determine the final total.