Calculating the date value and the difference one date back (Classed as week v week?)

[browna6]

Hi

I am looking to find at what the increase in value is (and percentage) to the previous date in my date column.

I would class it as a week on week difference - however, i only have the Monday date each week available.

Is this possible? The table below is some example data - i am trying to achieve the outcomes withi the 'Week on Week Difference' column and the & Difference column

Thank you in advanced

Date	Value	Week on Week Difference	% Difference
27/02/2023	49246997
06/03/2023	48361947	-885050	-1.8%
13/03/2023	37187599	-11174348	-23.11%
20/03/2023	45926791	8739192	23.5%
27/03/2023	45581085	-345706	-0.75%

[Alf94]

Hi @browna6 ,

Could you please try the following measure for the week over week difference?

Week on Week Difference = 
    VAR prevValue =
        CALCULATE(
            SUM( Table[Value] ),
            OFFSET(
                -1,
                ORDERBY( Table[Date] , ASC )
            )
        )
    RETURN
        IF(
            NOT( ISBLANK( prevValue ) ),
            CALCULATE(
                SUM( Table[Value] ) - prevValue
            )
        )

Do not forget to replace "Table" with the correct name of your table. For the percentage, I wrote the following but do not find the same result as you (except for first and last value). Could you explain your calculation?

Difference % = 
    CALCULATE(
        DIVIDE(
            [Difference],
            SUM( Table[Value] )
        )
    )

Thanks,

If my solution is correct, please mark it as a solution to help people with the same question as you in the future.