I have used the following in an unbound text box in a report;
=Sum(Abs([mycheckboxfield]))
MartijnAn did you put Rich's suggestion in the Report footer or page footer?
In the report footer it will add up all the true's and if you create a footer based on one of your fields it will add up the true's on each page. Well, it does in my reports. Don't think it works in the page footer.