What SUM does
Add numeric values, usually for sales, quantity, cost or hours. In Power BI, the key is not only the formula itself but how it behaves with slicers, relationships, visuals and totals.
Syntax or pattern
SUM(column)5 practical business examples
Total sales measure
Add all revenue values from the Sales table.
Total Sales = SUM(Sales[Sales Amount])Use this as a base measure for revenue cards, trends and comparisons.
Total quantity sold
Add the number of units sold.
Total Quantity = SUM(Sales[Quantity])Useful for volume reports and inventory analysis.
Total discount amount
Summarize discounts from transactions.
Total Discount = SUM(Sales[Discount Amount])Use this to monitor promotional cost.
Total cost
Add cost values for margin calculations.
Total Cost = SUM(Sales[Cost Amount])This can feed profit and margin measures.
Total hours
Add hours logged by employees or projects.
Total Hours = SUM(Timesheets[Hours])Useful for utilization, billing and workforce reports.
Common mistakes to avoid
- Using SUM before checking whether the data model has the right relationships and filter direction.
- Writing one complex measure instead of creating simple base measures first.
- Testing only at the total level and not checking row, category and date contexts.
- Forgetting that slicers, visuals and relationships can all change the filter context.
FAQ
When should I use SUM in DAX?
Use SUM when the calculation pattern matches the business question and the result behaves correctly in the current filter context.
Why is my SUM measure returning the wrong total?
Most total issues come from row context, filter context, relationships, or using a column aggregation where an iterator or CALCULATE pattern is needed.
Can I use this SUM pattern in a calculated column?
Some patterns work in calculated columns, but most reporting calculations should be measures so they respond to slicers and report filters.