Created by: Paul Pitcher
Creation Date: Aug 16, 2025
Updated Date: Oct 14, 2025

Sigma letter ∑

Also called: Sigma, Sigma sign, Sigma Symbol
In power BI The sigma letter indicates that an implicit measure is available. Power BI will automatically sum or average values in a numeric column. If the sigma letter is not present it indicates that Power BI thinks that the column isn't numeric. You can look at this in more detail by going into power query (transform data) and check to see what kind of data is in the column. Does the data look like it of numeric type? For example if some of the data is text and some is numeric then the entire column couldn't be summed or averaged.
Tip: If the entire column is empty then it would also not have the sigma sign displayed in Power BI.