You can save yourself a lot of calculations and just use the tools at www.costbasistools.com. Go to https://www.costbasistools.com/silver/SLV.php for SLV or https://www.costbasistools.com/gold/GLD.php for GLD to determine the cost basis and capital gain/loss for each of the monthly sales transactions, then just enter/edit the information in Turbotax as needed. These tools will also tell you what the adjusted cost basis is for your shares after subtracting out all of the previous sales. Much easier than doing all of the calculations yourself.
