Sum (filter by same date)

You add your measure in the Power BI desktop, not in the table. You right click and select new measure. After that, you will be able to change the name (by default it should write "measure") and enter the formula.

Sébatien

Anonymous if you want a monthly view you can:

1) Create a calculated column (in the same table of the "NewColumn") to show the month.

2) Then you can put "Month" and "NewColumn" into a visualization, and it automatically recalculate the value.

#I'M Not An Expert#

I've used the FORMAT() Function to show the month's name. If you want to display something else you can change the format (ex. "mmmm") using these.