multiple sum ifs

[dmheller]

All,
I have this equation
=SUM(IF(ISNUMBER(B4:B200),IF(MONTH(B4:B200)=MONTH(R3),--((C4:C200))))
B is a list of dates
R3 is a drop down of months
C4 is data or numbers
What I need to do is for February, I need to sum feb then sum Jan and then I need to do this math (What I want = ((Feb+Jan)-Jan).
This will be the same for every month. Can someone tell me how to nest the sum(ifs?
thanks

 

[Gerald Higgins]

Why do you need to do
((Feb+Jan)-Jan)
?

If you can identify Feb, why not just take Feb?

Algebraically, ((A+B)-B) = A

 

[dmheller]

You are correct, I wroth the math wrong. I need just Feb-Jan.