Selling on an average cost basis - is cost to acquire total or average?

I am using the HMRC Capital Gains Calculator to figure out the amount I may owe for the sale of shares. This is being done using the average cost basis (Section 104 holding) and everything was in line with what I've read about this. However, the calculator also asks for cost of sale and purchase in terms of broker fees. For sale this is easy as it's a single fee, but I am unclear how I calculate cost to acquire the shares. Should I simply total the fees for all share purchases up until the current date, or is this also done using an average?

Hi Paul,
You will still need to take an average of the total costs.
Thank you.