6. Configure formula column
To display the total amount of wine sold in liters, a formula column is added. Via Add Custom a new custom column is created. Enter "Quantity total (l)" as the title.
In the Calculation field, the following operators + - / * can be used to perform the basic arithmetic operations. Use to show the drop-down menu for further calculation operators as well as columns / custom fields.
For the total quantity, the column Bottle size (cl) is to be multiplied by the number sold and divided by 100, so that the unit is converted from cl to liters.
The bottle size is selected via the dropdown, so there is no need to look up the $customField21 variable.