The Estimates To Completion selection criteria for this report allows you to specify which data attributes to include in the output.   The "Calculated" values are intended to provide a revised view of user entered ETC information, by considering actuals entered after the user last updated the ETC estimates.  The options include:

Actuals + Calc. Hours      *Only those Actuals from users having entered an Hours (ETC) value for their assignment will be considered.

Hours (ETC)  -  Sum of Actuals Hours entered after the ETC value was entered

More specifically, the user entered Hours (ETC) value minus the sum of actual hours entered where the work date is greater than Estimates To Completion -- Last Updated On date

Actuals + Calc. Hours     *Only those Actuals from users having entered an Hours (ETC) value for their assignment will be considered.