Add each purchase with the number of shares (or units or coins) and the price you paid. You get your average cost per share, the total you’ve invested, and, if you enter today’s price, your gain or loss.
How many more shares would you need to buy at a new price to bring your average to a target?
Your average cost is the total you’ve spent divided by the total number of shares you own. Buying 10 shares at 50 and 20 shares at 35 costs 500 + 700 = 1,200 for 30 shares, an average of 40 per share. It’s weighted by the number of shares, so it isn’t simply the average of the two prices (42.50).
Fees are added to what you paid, which nudges your average up slightly. The price you need to sell at to get your money back is your average cost plus any selling fee, spread across your shares.
Averaging down means buying more at a lower price to reduce your average. To reach a target average T by buying at price P, you need shares = current shares × (current average − T) ÷ (T − P). The target has to lie between the new price and your current average, which is why averaging down gets very expensive as the target nears the new price.
Add up what you paid for every purchase (shares × price, plus fees), then divide by the total number of shares. 10 shares at 50 and 20 at 35 gives 1,200 ÷ 30 = 40 per share.
Under the average-cost method, selling doesn’t change the average cost of the shares you keep; it only reduces how many you hold. Just remove the sold shares from your total. Some countries use FIFO or specific-lot rules for tax instead.
Buying more of something you already own after its price has fallen, which lowers your average cost per share. It means the price needs to recover less for you to break even, but it also increases how much you have riding on that one holding.
Yes, for a true picture. Brokerage or exchange fees are part of what you paid. Most tax systems also let you add purchase fees to your cost basis.
Yes. Enter coins or fund units as “shares” and set the price decimals to 8 for crypto amounts that need them.
