Profit Ratio is a common example of Calculated Field from Basic Calculations. However, the level of aggregation/granularity must be considered while defining this new column

**Profit Ratio = Profit/Sales **

However, when aggregated, Profit and Sales must be aggregated separately and then the aggregated values are divided.

Profit Ratio = SUM([Profit])/SUM([Sales])

Profit Ratio wo Aggregation = Profit/Sales

The first formula calculates total sales and total profit in the context, then divides then which makes sense.

The second formula calculates Profit/Sales first and then aggregated to SUM(Profit/Sales) in the context. It does not make any sense.

The two formulas give different results unless in the finest level of granularity where there is no aggregation at all.

Each OrderID and Product Name gives the finest level of granularity so both formulas returns the same result

However, the Product Name itself is a context and data is aggregated in that context. Therefore, the two formulas returns different results. Profit Ratio wo Aggregation does not make any sense at all.