The Forecast Sheet tool was introduced in Excel 2016 and resides in the Forecast group of the Data ribbon.
To use the Forecast Sheet tool, select the range of cells that contains the dates and historical sales, then click the Forecast Sheet button.
This presents us with a preview of the forecast output.
We can choose between a line chart or a column chart (upper right).
The blue lines/bars represent the ACTUAL values while the orange lines/bars represent the FORECAST values.
While the thicker orange line represents the FORECAST, the thinner orange lines represent the upper and lower confidence bounds.
In a bar chart rendition, the upper and lower confidence bounds are represented as Vertical Error Bars.
If your Confidence is set to 95% (this is Excel’s default setting), then 95% of your future data points should fall between the upper and lower bounds.
You can alter the forecasting end date by changing it in the Forecast End date picker (lower left).