List.Average Function in Power Query

The List.Average function in Power Query returns an average value from a list of values. The result is given in the same datatype as the values in the list. Only works with number, date, time, datetime, datetimezone and duration values. If the list is empty null is returned.

Syntax

Example: Find the average of the list of numbers.

Power Query M

let
    Source = List.Average({3, 4, 6, null,0})
in
    Source 

The output of the above code is 3.25.

Explanation: Power Query automatically ignores null values when calculating the average. Here’s how it works:
1. The list {3, 4, 6, null, 0} is parsed.
2. null is treated as a non-existent value and excluded from the calculation.
3. The remaining numbers are summed: 3 + 4 + 6 + 0 = 13.
4. The count of non-null values is 4 (since null is skipped).
5. The average is 13 / 4 = 3.25.