Formula for Dynamic Rolling Sum

Hi,

In D3 enter

Formula:

=EOMONTH(C3,0)+1

and copy across

In T4 Enter

Formula:

SUMIFS($C4:$S4,$C$3:$S$3,">="&EOMONTH(TODAY(),-12)+1,$C$3:$S$3,"<="&EOMONTH(TODAY(),0))

and in U4

Formula:

=SUMIFS($C5:$S5,$C$3:$S$3,">="&EOMONTH(TODAY(),-12)+1,$C$3:$S$3,"<="&EOMONTH(TODAY(),0))

and copy down

Incidentally I'd urge you not to use merged cells. One day they will trip you up. Most of us avoid them like the plague for reasons that needn't concern us just at the moment.