Help with a sum calculation please.

[ballst]

Hi,



Currently working with a really big spreadsheet containing tens of thousands of row of data.

At random intervals within the data there is a sub total which I need to calculate and then average. The trouble is the randomness of where the info appears. The data I need to calculate is always in Column C to the right of a cell in column B that is called total.

I'm guessing there is some method of searching the totals and adding what is next to them, only trouble is I don't really know how, hence my desperate plea!

If anyone does have an idea it would be much appreciated.

Thanks for reading.