Loop calculation

Hi BCAdmin ,

I have a test on amitchandak's code and I find that I won't return the result you want. Firstly, we need to add an Index column in Power Query if you only have month column in text format.

Your table will be like as below.

Then add calculated columns in this table.

Column4 = 
VAR _START =
    CALCULATE ( SUM ( 'Table'[Column1] ), ALL ( 'Table' ) )
RETURN
    _START
        + SUMX (
            FILTER ( 'Table', 'Table'[Index] <= EARLIER ( 'Table'[Index] ) ),
            [Column2] - [Column3]
        )

New Column1 = 
VAR _PREVIOUS_COLUMN4 =
    CALCULATE (
        SUM ( 'Table'[Column4] ),
        FILTER ( 'Table', 'Table'[Index] = EARLIER ( 'Table'[Index] ) - 1 )
    )
RETURN
    IF ( ISBLANK ( 'Table'[Column1] ), _PREVIOUS_COLUMN4, 'Table'[Column1] )

Result is as below.

Best Regards,
Rico Zhou

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