What is default aggregation and why does it matter?

< 1 min read

Default aggregation is the automatic summarization applied to a numeric column when used in a visual.
It can be Sum, Average, Count, etc., based on model settings.
Power BI applies this when a user drags the field into a report.
It matters because incorrect defaults can lead to wrong KPIs.
For example, if Unit Price defaults to Sum, totals become misleading.
In one project, I changed default aggregation to “Do Not Summarize” for rate columns.
This prevented calculation errors in dashboards.
Setting correct default aggregation ensures data accuracy and consistent reporting.

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