no choice: an excel file with drp price and exact date + same for dividends

And each year lop a bit off each parcel proportionately for the tax deferred distribution component.

Thanks for everyone's feedback.

I thought it might be a bit complicated. Ok, so Vanguard provides me with a yearly tax summary statement - so I think I might start with that. As well a complete transaction history which I can bring into a spreadsheet.

But I am still confused as to what to do calculation wise. How can I work out the CGT impact of removing say $50k from a an overall portfolio value of $1M....when the first investment in the Wholesale Balanced Vanguard Fund started back in 2016, at around $200k, and since then I have been adding more funds and reinvesting the distributions. This means that some of the recent earnings in the portfolio may not allow the 50% CGT discount rate. Or does the CGT just look at the start date of the portfolio, as opposed to top up dates to make that determination?

Also I don't know when building the calculations if I take an average of the purchase price to date for units and then compare that to the current value to sell the units to see what loss or gain has been made by understanding the averages. I can't think of how else you can do it. I hope I am making sense!

I know I will have to get my accountant involved, however, I like to try to work things out for myself so I have a better understanding of it all.