DAX for a Fraction that changes with respect to Numerator & Denominator:

[SoyeFBI]

I need help in creating a DAX that changes once we have both the numerator and denominator for a Month.

Reconciliation Factor April  = Numerator/Denominator;

So for May; I want the Reconciliation Fatcor to change once I update Numerator and Denominator as the current Reconciliation Factor.

so this is the DAX i use at the moment:

Latest_RF = CALCULATE('RF Dashboard'[RF_DEF],'Date'[Year]=2023 && 'Date'[Month]="Apr-2023")

where,

RF_DEF = IF(ISBLANK(CALCULATE(DIVIDE([TOTAL_A],1000*[TOTAL_B]))),0,CALCULATE(DIVIDE([TOTAL_B],1000*[TOTAL_A])))

Month	A	B	RF (%)
Jan-2023	20000	15000	75%
Feb-2023	30000	10000	33%
Mar-2023	25000	15000	60%
Apr-2023	15000	10000	67%

How can I modify this DAX so at any filter it shows the latest RF? that is if values (A&B) are entered for May-2023, it automatically shows the latest RF.

Latest_RF = CALCULATE('RF Dashboard'[RF_DEF],'Date'[Year]=2023 && 'Date'[Month]="Apr-2023")

[SoyeFBI]

How can I dynamically create the variable for last month that changes with time?

[lbendlin]

Latest_RF =

var maxmonth= maxx('Table',[Month])

return calculate(max('Table'[RF (%)]),'Table'[Month]=maxmonth)

[lbendlin]

Before you calculate Latest_RF  you add a step to assign a variable to the latest month with data. Then use that variable in your CALCULATE filters.