How to write DAX for % change

[manojk_pbi]

Hi Friends,

I am looking for a DAX measure to calculate Change in Percentage w.r.t to a particular period by Products. Please suggest me how can we write the optimized DAX for the same. Provided a sample with required output. Baseline is Jan-23 data, this can vary as per business request. Any suggestions are much appreciated.

MY            Product   Qty          %Change

Jan-23	PROD1	100
Feb-23	PROD1	120	20%
Mar-23	PROD1	135	35%
Apr-23	PROD1	140	40%
May-23	PROD1	120	20%
Jun-23	PROD1	100	0%
Jul-23	PROD1	80	-20%
Aug-23	PROD1	90	-10%
Sep-23	PROD1	75	-25%
Oct-23	PROD1	100	0%
Nov-23	PROD1	80	-20%
Dec-23	PROD1	65	-35%

Thanks

[manojk_pbi]

Thanks for your solution. It's perfect. 

[manojk_pbi]

Thanks for your solution. It's perfect. 

[lbendlin]

That is a very, very subjective topic especially when sign changes are involved (like in your case).

One approximation is DIVIDE(current-previous, ABS(previous),BLANK())

But at the end of the day you have to decide what is a reasonable number in your scenarios.

[manojk_pbi]

Thanks for your input.

I am looking for suggestion on writing measure to calculate % Change .

[v-yiruan-msft]

@lbendlin  Thanks for your contribution on this thread.

Hi @manojk_pbi ,

@lbendlin already gave the related formula. If you want to get the expected result base on your sample data, you can create a measure as below to get it:

%Change = 
VAR _MY =
    SELECTEDVALUE ( 'Table'[MY] )
VAR _preMY =
    CALCULATE ( MIN ( 'Table'[MY] ), ALLSELECTED ( 'Table' ) )
VAR _preqty =
    CALCULATE (
        SUM ( 'Table'[Qty] ),
        FILTER ( ALLSELECTED ( 'Table' ), 'Table'[MY] = _preMY )
    )
RETURN
    IF (
        _MY = _preMY,
        BLANK (),
        DIVIDE ( SUM ( 'Table'[Qty] ) - _preqty, _preqty )
    )

Best Regards

[manojk_pbi]

@v-yiruan-msft , this is perfect. Thanks for the working sample. If i were had to add Product into filter to calculate % Change for each product what changes to be made here ? 

Pls suggest

[v-yiruan-msft · Accepted solution]

Hi @manojk_pbi ,

Please update the formula of measure as below to get it, please find the details in the attachment.

%Change = 
VAR _MY =
    SELECTEDVALUE ( 'Table'[MY] )
VAR _product =
    SELECTEDVALUE ( 'Table'[Product] )
VAR _preMY =
    CALCULATE (
        MIN ( 'Table'[MY] ),
        FILTER ( ALLSELECTED ( 'Table' ), 'Table'[Product] = _product )
    )
VAR _preqty =
    CALCULATE (
        SUM ( 'Table'[Qty] ),
        FILTER (
            ALLSELECTED ( 'Table' ),
            'Table'[Product] = _product
                && 'Table'[MY] = _preMY
        )
    )
RETURN
    IF (
        _MY = _preMY,
        BLANK (),
        DIVIDE ( SUM ( 'Table'[Qty] ) - _preqty, _preqty )
    )

Best Regards