How To Create Year Over Year Growth Measure In DAX

1. Create Sales Measure

Sales = 

SUMX ( Sales, Sales[Quantity] * Sales[Net Price] )

2. Create Previous Year Sales Measure

Sales PY = 

    CALCULATE (

        [Sales],

            DATEADD ( 'Date'[Date], -1, YEAR )

             )

3. Create YOY Sales Measure

Sales YOY = 

VAR ValueCurrentPeriod = [Sales]

VAR ValuePreviousPeriod = [Sales PY]

VAR Result = IF (

        NOT ISBLANK ( ValueCurrentPeriod ) 

            && NOT ISBLANK ( ValuePreviousPeriod ),

        ValueCurrentPeriod - ValuePreviousPeriod )

RETURN    Result

4. Create YOY Growth % Measure

Sales YOY % = 

DIVIDE ( 

    [Sales YOY],

    [Sales PY]

)