Excel - Microsoft Excel Forecast Function

Description

The Excel Forecast function predicts a future point on a linear trend line fitted to a supplied set of x- and y- values. 

The syntax of the function is: 

FORECAST( x, known_y's, known_x's ) 

Where the arguments are as follows : 

Forecast Function Example

The spreadsheet below shows an example of the Forecast function used to predict an additional point along the straight line of best fit through the known_x's and known_y's in cells F2:F7 and G2:G7. These known points are shown in the graph on the same spreadsheet. 

The above example gives the result 32.666667. 

Forecast Function Errors

If your Forecast function gives you an error message, use the table below to look up the likely cause: 

Common Errors