5 Ways To Calculate Running Average In Power Query Excel

Calculating a running average in Power Query Excel is a valuable skill, especially when dealing with large datasets that require dynamic analysis. The running average, also known as the moving average, helps in understanding trends and patterns over time or across different categories. Power Query, a powerful data manipulation tool in Excel, provides several methods to calculate the running average efficiently. Here, we'll explore five different ways to achieve this.

The importance of calculating running averages cannot be overstated. It helps in smoothing out fluctuations in data, highlighting long-term trends, and making predictions based on historical data. Whether you're dealing with stock prices, temperatures, or sales figures, understanding how to calculate a running average is crucial for data analysis.

Method 1: Using the "Group By" Function

One of the most straightforward methods to calculate a running average in Power Query is by using the "Group By" function. This method is particularly useful when you want to calculate the running average for a specific group or category.

= Table.Group(#"Previous Step", {"Category"}, {{"Running Average", each List.Average(List.Range([Value], 0, List.PositionOf([Value], _)) + [Value]), type nullable number}})

This formula groups your data by a specific category and then calculates the running average by taking the average of the current value and all previous values within each group.

Method 2: Utilizing the "List.Accumulate" Function

The "List.Accumulate" function is another powerful tool in Power Query that allows you to perform cumulative calculations, including the running average.

= Table.FromColumns({#"Previous Step"[Category], List.Accumulate(#"Previous Step"[Value], 0, (state, current) => state + current) / List.Position}, type table [Category=nullable text, Running Average=nullable number])

This method accumulates the values in your list and divides by the position to get the running average. It's a bit more complex but offers flexibility in handling different types of calculations.

Method 3: Applying the "List.Generate" Function

For those who prefer a more iterative approach, the "List.Generate" function can be used to calculate the running average by generating a list of cumulative averages.

= Table.FromColumns({#"Previous Step"[Category], List.Generate(() => 0, each _ < List.Count(#"Previous Step"[Value]), each _ + 1, each List.Average(List.Range(#"Previous Step"[Value], 0, _ + 1)))}, type table [Category=nullable text, Running Average=nullable number])

This method generates a list where each element is the average of the first 'n' elements of your original list, effectively giving you the running average.

Method 4: Leveraging DAX Measures in Power Pivot

If you're working within the Power Pivot environment, you can leverage DAX (Data Analysis Expressions) measures to calculate the running average. This method is particularly useful when you need to analyze data in a PivotTable.

Running Average = CALCULATE(AVERAGE('Table'[Value]), FILTER(ALL('Table'), 'Table'[Date] <= MAX('Table'[Date])))

This DAX measure calculates the average of the values in your table, filtered by dates up to the current date, providing a running average over time.

Method 5: Using M Language with a Custom Function

For more complex or customized calculations, you can create a custom function in M Language that calculates the running average. This method offers the most flexibility but requires a deeper understanding of Power Query's scripting language.

= (list as list) as number =>
let
    runningTotal = List.Accumulate(list, 0, (state, current) => state + current),
    count = List.Count(list),
    average = runningTotal / count
in
    average

You can then invoke this function within your Power Query script to calculate the running average for any list of values.

Each of these methods has its own strengths and can be chosen based on the specific requirements of your project, such as the nature of your data, the desired output, and your familiarity with Power Query and DAX.

Gallery of Power Query Functions

Whether you're an Excel novice or an advanced Power Query user, understanding how to calculate a running average is a critical skill that can enhance your data analysis capabilities. By choosing the method that best fits your needs, you can unlock deeper insights into your data and make more informed decisions.

We encourage you to experiment with these methods and explore the vast capabilities of Power Query and Power Pivot. Share your experiences, ask questions, or provide tips in the comments section below.