Why am I getting Overflow Error? VBA EXCEL

Why do I get this “Overflow” error when trying to output certain results towards the Excel file?

        'calculating the total CGs across all of the bays
        For ii = 1 To bayCount
            .cells(bayCount + 2, 3) = .cells(bayCount + 2, 3) + .cells(ii + 1, 2) * .cells(ii + 1, 3)
            .cells(bayCount + 2, 4) = .cells(bayCount + 2, 4) + .cells(ii + 1, 2) * .cells(ii + 1, 4)
            .cells(bayCount + 2, 5) = .cells(bayCount + 2, 5) + .cells(ii + 1, 2) * .cells(ii + 1, 5)
        Next ii
       .cells(bayCount + 2, 3) = .cells(bayCount + 2, 3) / .cells(bayCount + 2, 2)
       .cells(bayCount + 2, 4) = .cells(bayCount + 2, 4) / .cells(bayCount + 2, 2)
       .cells(bayCount + 2, 5) = .cells(bayCount + 2, 5) / .cells(bayCount + 2, 2)

What I’m looking for is just to get the results from the previous calculations and fill the excel sheet. I was told that it could be the size of the numbers that might be exceeding the limits.