divide values in column rows

[JAnderson]

I have Sold To Customer in the blacked out row and sales dollars based on years/months in the slicers.   It all comes from the same database.   I've read every post out there and can not figure out how to add a % difference column between 2016/2017 and 2017/2018.     Data is not a static database, it updates from a server 4X per day to populate the numbers.   How do I write this in DAX to add % increase or decrease based on each row in the columns? 

[lisaeugene · Accepted solution]

I'm doing almost the same exact calculation for certain costs, too. I use the exact same slicer you're using. Here's how I've done it. 

1. Create a measure to calculate this year's sales. TOTALSALES = SUM( YourTable[YourSales_Amt])
2. Create 2nd measure to calculate sales for prev yr: TOTALSALES LY = CALCULATE([TOTALSALES],SAMEPERIODLASTYEAR('Date'[Date]))
3. Create 3rd measure to calculate difference between last year and this year: DIFF BTW TY AND LY = IF( ISBLANK( [TOTALSALES LY]), BLANK(), [TOTALSALES] - [TOTALSALES LY])
4. Create 4th measure to calc percent diff between the two years. PCT DIFF BTW TY and LY = [Diff btw TY and LY] / [TOTALSALES LY]

I'm sure there is a more elegant way to do this with DAX, but I'm still learning Power BI, so my formulas and procedures are more basic. Hope this helps. 

Hope this helps!