Power BI (DAX): Calculating MoM Variance of a Measure Field
<p>I have measure formula that takes a table and converts it to monthly count of distinct customers:</p>

<pre><code>Active Publishers =
CALCULATE(
DISTINCTCOUNT( 'Net Revenue Data'[Publisher Name] ),
'Net Revenue Data'[Active Month] = 1)
</code></pre>

<p><a href="https://i.stack.imgur.com/fGXra.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/fGXra.png" alt="enter image description here"></a></p>

<p>Now, I would like to create a new formula that takes the Month-Over-Month (MoM) variance of this trend, like this: </p>

<p><a href="https://i.stack.imgur.com/OIbkx.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/OIbkx.png" alt="enter image description here"></a></p>

<p>This is the formula I attempted to get the net monthly change:</p>

<pre><code>Net Change = 'Net Revenue Data'[Active Publishers] - 
CALCULATE('Net Revenue Data'[Active Publishers], 
PREVIOUSMONTH('Net Revenue Data'[Date (Month)]))
</code></pre>

<p>How can I create a measure that takes the monthly variance of the 'DistinctCountActiveMonths' measure?</p>

<p>I created an additional date table to relate to the revenue table's date column:</p>

<pre><code>Date Table = 
ADDCOLUMNS(CALENDAR("1/1/2000","12/31/2025"),"DateAsInteger",FORMAT([Date],"YYYYMDD"),  "Year",YEAR([Date]),  "MonthNumber",FORMAT([Date],"MM"),"YearMonthNumber",FORMAT([Date],"YYYY/MM"),"Ye arMonthShort",FORMAT([Date],"YYYY/mmm"),"MonthNameShort",FORMAT([Date],"mmm"),"MonthNameLong",FORMAT([Date],"mmmm"),"DayOfWeekNumber",WEEKDAY([Date]),"DayOfWeek",FORMAT([Date],"dddd"),"DayOfWeekShort",FORMAT([Date],"dddd"),"Quarter","Q"&amp;FORMAT([Date],"Q"),"YearQuarter", FORMAT ( [Date], "YYYY" ) &amp; "/Q" &amp; FORMAT ( [Date], "Q" ))
</code></pre>

<p>Now I should be able to relate the two tables to create Month over Month variance.</p>