SamesPeriodLastYear vs Using Var + Return

[MatthewCunliffe]

Hi there!

I've recently completed a finance-oriented course on DAX and Power Pivot/BI. 

When calculating sales growth in dollar $ terms the instructor offered 2 different solutions, but with a different outcome:

Measure 1: SalesPY:=CALCULATE([Sales],SAMEPERIODLASTYEAR(Dim_Dates[Date]))

Measure 2: 

Sales$Growth:=var PYSales = CALCULATE([Sales],SAMEPERIODLASTYEAR(Dim_Dates[Date]))

return [Sales] - PYSales

The outcome is different one from the other. 
Thanks in advance!

[tamerj1 · Accepted solution]

Hi @MatthewCunliffe 

Because they are two different calculations. The 2nd measure returns the difference between the current year and the previous year which is clearly indicated by the measure name.