DAX to work out the Previous Months Total

[johnandrews1987]

Total Last Month = CALCULATE(SUM('Report Data'[Amount]),DATEADD('Date'[FullDateAlternateKey].[Date],-1,MONTH)

This DAX works great, for every month except January, where I'd like to get the previous Years December figures.

Any ideas? I thought an IF statement might work but I couldn't get it to.

[littlemojopuppy]

@johnandrews1987 question for you: are you intending for the total on the date one month prior?  Or the total for the entire previous month?

[johnandrews1987]

@littlemojopuppy - it would be for the entire previous calendar month, so in January, what did we do in December. Thanks!

[littlemojopuppy · Accepted solution]

@johnandrews1987 

Try this

Total Last Month = 
CALCULATE(
	SUM('Report Data'[Amount]),
	PREVIOUSMONTH('Date'[FullDateAlternateKey])
)

Requires that you have a date table and that it is marked as one.