daily variance in DAX

Hi topazz11 

Can you please check this Calculated column and give headsup if it works ,if not please let us know.

Daily Variance =
VAR CurrentDate = table[Date]
VAR CurrentValue = table[Value]

VAR PreviousValue =
CALCULATE (
MAX ( table[Value] ),
FILTER (
table,
table[Date] =
CALCULATE (
MAX ( table[Date] ),
FILTER ( table, table[Date] < CurrentDate )
)
)
)

RETURN
IF (
ISBLANK ( PreviousValue ),
0,
CurrentValue - PreviousValue
)

You can do this in a regular measure, sure. BUT! It's a lot easier in a visual calculation!
Right click on your table and hit 'New visual calculation' then versus previous.
You should already have 90% of what you want once you plug in the fields but if you want that first date not to be included make sure it looks like this:

I think this can be easily handled using DATEADD function. Below is the code I have used in my sample dataset to calculate variance vs previous day:

Daily_Variance =

VAR CurrentValue = SUM(DailyVar[Daily Value])

VAR PreviousValue =

CALCULATE(

    SUM(

        DailyVar[Daily Value]

    ),

    DATEADD(

        DailyVar[Order Date],

        -1,

        DAY

    )

)

RETURN

CurrentValue - PreviousValue

 

My sample data set

Order Date	Daily Value
12/10/2025	178
12/11/2025	192
12/12/2025	102
12/13/2025	182
12/14/2025	109
12/15/2025	187
12/16/2025	155
12/17/2025	119
12/18/2025	172
12/19/2025	120

 

Power BI result set:

I hope this helps.

Thanks.

Please check the formula below:

Daily Variance =
VAR PrevValue =
    CALCULATE (
        MAX ( 'Table'[Value] ),
        DATEADD ( 'Table'[Date], -1, DAY )
    )
RETURN
MAX ( 'Table'[Value] - PrevValue, 0 )