When adding activities to a custom table you can set the options to calculate the total values of the attached activities. These total values will be stored in fields on the custom table record. ( Requires Impact 5.1 or better)

To turn on this option please follow these steps:

1. Open the custom table data-entry form in the designer
2. Click on the "Parent-Child lists' icon on the toolbar
3. From the toolbox on the left side drag the Activities control onto the form.
4. In the Quick Properties panel set the value of CalculateTotals to True
5. Save and close the form.

Now attached activities will be calculated into these fields:

Activities Count Number
Activities Count Closed Number
Activities Count Open Number
Activities Count Percentage Decimal

See also