Aggregations
DAX SUM Function
The bedrock aggregator for numerical columns in Power BI.
Syntax Definition:
SUM( Table[Column] )
Overview
SUM adds all numbers in a column. It automatically respects the current filter context set by slicers, rows, columns, and visual filters.
Architectural Deep Dive
The SUM function accepts a single column reference. It cannot evaluate arithmetic expressions (like Price * Quantity) inside its arguments—for row-by-row math, use SUMX instead. Under the hood, SUM is optimized by Microsoft VertiPaq and operates directly against compressed columnar storage.
Canonical Pattern Example:
Total Revenue = SUM(Sales[Revenue])
Common Anti-Patterns & Mistakes to Avoid
- •Passing an expression instead of a column (e.g., SUM(Sales[Qty] * Sales[Price]) will cause a syntax error; use SUMX instead).
- •Using SUM in calculated columns when you intend dynamic report visual behavior.
- •Attempting to sum text or boolean values.
Interactive Challenge
Put DAX SUM Function into practice
Solve "Calculate Total Revenue" in our interactive Monaco editor with live dataset verification.