Average Down Calculator
Enter up to 5 buys to get your blended cost basis, total shares invested, and — if you add a current price — your unrealized P&L and percentage move needed to break even.
Tired of recalculating cost basis every time you scale in? Fuselit tracks blended cost and triggers automated rebuys on your Alpaca account.
Try Fuselit free →How to use this calculator
Add a row for each purchase: the price you paid and the number of shares. Optionally enter the current market price to see your unrealized profit or loss and how far the stock has to move to reach break-even.
Why blended cost basis matters
Your blended cost basis is what every decision after entry should be measured against — your break-even, your tax lots, your trail stop reference. Tracking it in your head while scaling into a position is how mistakes happen. A 30-second calculation now prevents an unrecoverable position later.
Frequently asked questions
How do you calculate the average cost of a stock?
Multiply each buy's price by the number of shares bought, sum those values across all buys, then divide by the total shares. The result is your blended (weighted average) cost basis per share.
What does it mean to average down on a stock?
Averaging down means buying additional shares at a price below your original entry, which lowers your average cost per share. It reduces the price the stock needs to reach for the position to break even — but it also increases your total exposure.
Is averaging down a good strategy?
It depends on why the price dropped. Averaging down on a fundamentally sound stock that's facing temporary weakness can work. Averaging down on a stock in structural decline compounds losses. Always have a maximum total position size in mind before you start adding.
How do I calculate break-even after averaging down?
Your break-even price is your blended average cost. The percentage move needed to break even is (average_cost − current_price) / current_price × 100. This calculator computes both automatically once you enter a current price.