A critical basic function in Microsoft Access is how to calculate a subtotal in a form. The process requires the user to add text boxes to a new or existing form and to set the respective name and ControlSource fields. The capability to provide a subtotal is an important part of the form creation process in Microsoft Access 2007 and is one that almost any field of study can utilise.
Open the form file in Access 2007. Click "File" and "Open," then select "Form."
Identify the columns on the table you want to calculate.
Create a report footer section by clicking "View" and "Report Header," then selecting "Footer."
Click on the Footer and enter "0" into the "Height" box.
Add a textbox to the footer and double-click it to modify its properties. Change the "Name:" to "Total" and change "ControlSource:" to "=Sum([column])." Replace "column" with the name of the column to be totaled.
Set the footer "Visibility Property" to zero.
Add an additional text box to the form below the sub-report. Set the text box's property "Name: " to "Sales Total", the "ControlSource: " field to "=[name_of_the_report].[Report]![Total], and the "Format:" to "Currency". Replace "name_of_the_report" with the report's name. The subtotal is now calculated in this box.