Sum column in Excel from 1 value in a separate column until a different value in the criteria

Question

I am trying to sum a column A based on a value in column B, but I only want to sum the values until I reach a different criteria value (in column B). When I reach that value, I want to reset the function & repeat.

A	B	Sum Value I'm looking for
12	N/A	12
34	N/A	46
21	N/A	67
45	BREAK	109
232	N/A	232
64	N/A	296
231	BREAK	527
423	BREAK	423
46	N/A	46
4	N/A	50
56	N/A	106
86	N/A	192
235	N/A	427
463	BREAK	890
3	N/A	3
57	N/A	60
75	BREAK	135

I have tried SUMIF but cannot get this to work. Any help would be greatly appreciated.

Thank you!

Answer 1

I've started using this formula (in cell C2):

=IF(B2="BREAK";A3;C2+A3)

This is not entirely correct, but it gives another idea: in order to repeat the calculation of the whole sum, you do this in an cumulative manner (first you get A2+A3 (which you put in cell C2), then A2+A3+A4 (which you put in cell C3), ...).

Answer 2

The following formula should work:

=SUM(A$2:A2)-SUMIF(B$1:B1,"BREAK",C$1:C1)

And populate down