Summary fields in custom reports, how to calculate sum

Q. Can I add a summary for a numeric field in a custom report created using the Report generator?

A. Yes, you can. When you add a new or edit an existing report in the Report generator, you should click on the "Edit" button beside any numeric field. Then mark the "Sum" checkbox. Save your report. Next time you run it, a summary for the chosen field will be displayed at the bottom of the page.