sum rows based on sub-total

[JackSmith123]

Hello Excel Gurus,

I'm looking for a formula or vba code that will calculate a total (or sub-total to be more precise) for rows that are constantly changing (i.e. dynamic range).

I have attached a spreadsheet for more information which is like a payroll time sheet.

In it, I have to go to each 'sub-total' row to calculate the sum for the activity for that particular location. As there are hundreds/thousands of rows I have to repeatedly hit the sum function for every sub-total line.

I've currently done this in cells:

F9 and G9
F20 and G20
F24 and G24
F32 AND G32

I'm wondering if there is an easier way to calculate all the rows that have a sub-total as an identifier. Either in the form of a formula/vba-code?

Any help would be appreciated.