» Summing Expenses Accumulated to a Specified Month

Problem:

Column B contains the expenses for each of the months January to July.
We want to create a formula that will sum the expenses for all the months between January and the month specified in cell D2.

Solution:

Use the SUM, OFFSET, and MATCH functions as shown in the following formula:
=SUM(OFFSET(B2,0,0,MATCH(D2,A2:A8,0),1))