Calculate correct total for a ratio

are we to assume these calculations will only ever be used in the context of a single employee, or should the calculation be able to handle scenarios where there are multiple employees in context?

If we assume a single employee, then this should help...

Mandatory =
VAR _mandatoryHours = 7.5 //mandatory hours per day

VAR __cur_resource_last_date = SELECTEDVALUE( Resource[EndDate] )

//WorkRatio from Calendar is either 0 or 1 based on the day of the year
VAR _daycalc =
    CALCULATE(
        SUM( Calendar[WorkRatio] ) * _mandatoryHours,
        FILTER(
            'Calendar',
            AND(
                'Calendar'[Date] <= 'Last Refreshed'[LastRefreshed],
                'Calendar'[Date] <= __cur_resource_last_date
            )
        )
    )
        * AVERAGE( Resource[Work Ratio%] ) //some resource are not 100% full time
VAR _calc = _daycalc * [Employee Count] //distinct count of resources
RETURN
    IF(
        ISINSCOPE( 'Calendar'[Date].[Year] ),
        _daycalc,
        _calc
    )
EVALUATE
 ( 'calendar' )