Measure not always providing the correct result

[ceaton]

I have two simple measures and I cannot figure out why one is not always providing the correct result.

Room_Use% is 

Room_Use% = DIVIDE(SUM('Section Info'[Actual Enrollment]),SUM('Room Info'[Room Capacity]))

Sometimes it provide the correct result:

And then sometimes, it's very off:

What needs to be adjusted in the measure to get the correct results consistently?

[Anonymous]

Hi @ceaton,

As we haven’t heard back from you, we wanted to kindly follow up to check if the solution provided for the issue worked? or Let us know if you need any further assistance?
If our response addressed, please mark it as Accept as solution and click Yes if you found it helpful.

Regards,
Vinay Pabbu

[ceaton · Accepted solution]

I was not able to get the formula to work.  So I copied the column to the same table and created a new measure based on both columns being in the same table.  Thank you all for your help!

[Anonymous]

Hi @ceaton,

Thank you for reaching out to Microsoft Fabric Community Forum.

There's likely no direct relationship between 'Section Info' and 'Room Info'—so the numerator and denominator may not be summing over aligned row contexts.

If this post helps, then please consider Accepting as solution to help the other members find it more quickly, don't forget to give a "Kudos" – I’d truly appreciate it!

Regards,
Vinay Pabbu

[ceaton]

I have two joins currently:

Here is the Timeblock Table:

And here's the Section Info table:

The second join is:

The second join is:

[Anonymous]

Hi @ceaton,

Thanks for confirming that the relationships are valid.

The issue with your current measure:

Room_Use% = DIVIDE(SUM('Section Info'[Actual Enrollment]), SUM('Room Info'[Room Capacity]))

is that it aggregates each side independently and doesn’t respect row-level alignment—especially in visuals that show data per room, per day, or per section. This can result in over- or under-estimation of the usage percentage.

To resolve this, you should use SUMX, which creates a consistent row context across both tables.

Regards,

Vinay Pabbu

[ceaton]

Thank you, but I am very new to Power BI and I've not used SUMX before.  How would I write the measure to pull from columns in two different tables?

[Anonymous]

Hi @ceaton,

Try this 

Room_Use% =
DIVIDE(
    SUMX(
        VALUES('Section Info'[Room ID]),  -- list of used rooms
        CALCULATE(SUM('Section Info'[Actual Enrollment]))
    ),
    SUMX(
        VALUES('Section Info'[Room ID]),  -- same room list
        CALCULATE(SUM('Room Info'[Room Capacity]))
    )
)

Regards,

Vinay Pabbu

[Ashish_Mathur]

Hi,

Share the download link of the PBI file.  Show the problem there very clearly.

[lbendlin]

That would be a question for your data model. How are these tables joined?