How it works
Your average share price (cost basis) is simply total money invested ÷ total shares owned. This calculator adds up every lot you bought and does the math.
What is averaging down?
Buying more shares after a price drop lowers your average cost, so the stock doesn’t have to climb as far for you to break even. It also increases your risk if the stock keeps falling — only average down on companies you’d happily buy at the lower price anyway.
Breakeven price
Your breakeven is the same as your average cost per share (before commissions). The stock must trade above this price for your position to be profitable.
Frequently asked questions
Does this include broker commissions?
No — add any commissions to the price you paid per share for a fully loaded cost basis.
What is a good average-down strategy?
Many investors buy in fixed tranches (e.g. every 10% drop) with money they can afford to lose, rather than going all-in at once.
How is unrealized gain calculated?
Unrealized gain = (current price − average price) × total shares. It’s ‘unrealized’ until you sell.