Excel: Forecast Function

In Excel, the Forecast function returns a prediction of a future value based on existing values provided.

The syntax for the Forecast function is:

Forecast( x-value, known_y_values, known_x_values )

x-value is the x-value used to predict the y-value.

known_y_values is the known y-values used to predict the y-value.

known_x_values is the known x-values used to predict the y-value.

Note:

If x-value is not a numeric value, the Forecast function will return the #VALUE! error.

If known_y_values and known_x_values contain different numbers of elements, the Forecast function will return the #N/A error.

Applies To:

Excel 2007, Excel 2003, Excel XP, Excel 2000

For example:

Let's take a look at an example:

Based on the Excel spreadsheet above:

=Forecast(8, {1,2,3}, {4,5,6}) would return 5

=Forecast(7, {5.8, -1}, {2, -5}) would return 10.65714286

=Forecast(50, {-1,-2,-3,-4}, {10,20,30,40}) would return -5

=Forecast(10, B2:B6, A2:A6) would return 20.03269866