Excel FORECAST.LINEAR function
The FORECAST.LINEAR function predicts a future value based on existing values by using the linear regression.
It returns a numeric value.
As shown in the table below, there is a list of monthly sales from January to August, to predict the future sales along the linear trend, you can try the FORECAST.LINEAR function as follows.
1. Create a helper column. In this case, I create a FORECASE column as shown in the screenshot below.
Tips: Creating a helper column helps to distinguish the predicted values from the actual values in a chart using different colors, which makes the chart more intuitive.
2. Find the cell containing the last sales (C13 in this case) in the Sales column, select a cell (D13) next to it in the helper column, and then enter a number that is the same as the last sales.
3. Select the cell D14, copy or enter the formula below and press the Enter key to get the result. Then select the result cell and drag its AutoFill Handle down to get other predicted values.
After getting all predicted values, you can create a forecast chart based on the table data according to your needs. See the screenshot below: