DAX Function for Year-to-Date Calculation with Total Value for Prior Years

The following DAX measure calculates the Year-to-Date (YTD) value for the maximum selected year in a slicer, while providing the total value for all preceding years.

DAX Measure

Total YTD with Preceding Total = 
VAR SelectedYear = MAX(YourDateTable[Year]) -- Get the maximum year selected from the slicer
VAR CurrentYTD = 
    CALCULATE(
        SUM(YourDataTable[Value]), -- Sum of the values for the current context
        DATESYTD(YourDateTable[Date]), -- Get YTD dates
        YourDateTable[Year] = SelectedYear -- Filter for the selected year
    )
VAR PreviousTotal = 
    CALCULATE(
        SUM(YourDataTable[Value]), -- Sum for total value of previous years
        FILTER(
            ALL(YourDateTable), -- Use ALL to get all years
            YourDateTable[Year] < SelectedYear -- Condition for previous years
        )
    )
RETURN 
    IF(
        ISBLANK(SelectedYear), -- Check if no year is selected
        BLANK(), -- Return blank if no year is selected
        IF(
            SelectedYear = MIN(YourDateTable[Year]), -- If only the minimum year is selected
            CurrentYTD, -- Only return YTD for that year
            CurrentYTD + PreviousTotal -- Return YTD plus total for previous years
        )
    )

Explanation of Code Blocks

1. Variable Declaration:

   • SelectedYear: Captures the maximum year selected in the slicer from the YourDateTable.
   • CurrentYTD: Calculates the YTD value for the year specified by SelectedYear using the DATESYTD function.
   • PreviousTotal: Calculates the total value for years prior to SelectedYear using the FILTER function combined with ALL.

2. Return Statement:

   • Checks if no year is selected; returns BLANK() if true.
   • Evaluates if the SelectedYear is the minimum year to only return the YTD value accordingly.
   • Returns the sum of the YTD and the total from previous years otherwise.

Usage Example

To use this measure in your Power BI report, follow these steps:

1. Load your data into Power BI Desktop.
2. Create a slicer for the year using the YourDateTable[Year] field.
3. Add a card or a table visual to display the Total YTD with Preceding Total measure.
4. Select a year(s) in the slicer to see how the calculation responds based on your selections.

Scenarios

• If the user selects 2023 in the slicer, the measure will return the YTD total for 2023 plus the total for all years prior to 2023.
• If the user selects 2022, it will return the YTD for 2022 plus the total for 2021, and so forth.
• If the user does not select any year, the measure will return BLANK().

Final Note

This measure ensures efficient computation and is aligned with best practices for DAX coding. Implementing this logic will enhance your reporting capabilities in Power BI, especially when dealing with time-based analysis. For further learning, consider exploring courses on the Enterprise DNA Platform that delve deeper into DAX calculations and time intelligence functions.