Use this free stock average calculator to find your blended average cost per share, break-even price, and unrealized profit or loss across multiple buys — whether you are averaging down or dollar-cost averaging into a position.
How the stock average calculator works
Enter the number of shares and the price for each purchase. The tool adds up what you paid in total and divides by your total shares to get your average cost per share. Add a current price to see your unrealized gain or loss, and a target percentage to see the price you would need to sell at to hit that profit.
How average cost is calculated
Average cost = total invested ÷ total shares, where total invested is the sum of shares × price for every buy. Break-even equals your average cost before commissions, fees, and taxes, which raise the true break-even.
Frequently asked questions
Does averaging down reduce risk?
It lowers your average cost and break-even, but it also increases your position in a falling asset. A lower average cost is not the same as a better investment.
Are fees and taxes included?
No. Figures are before commissions, fees, and taxes, which raise your real break-even.
Can I use it for ETFs or crypto?
Yes — the average-cost math is identical for any asset bought in multiple lots.
Educational tool, not financial advice. Investing involves risk, including the possible loss of principal.
Where to invest: brokers with fractional shares
To act on what this tool shows you, you’ll need a brokerage account. These are established brokers we use that support fractional shares — buying a slice of a share by dollar amount, which makes dollar-cost averaging and diversifying with small amounts easy:
- Charles Schwab — full-service broker whose “Stock Slices” let you buy fractional shares of S&P 500 companies from $5.
- Fidelity — “Stocks by the Slice” fractional investing from $1, with strong research and low-cost index funds.
Referral disclosure: the broker links above are referral links. If you open and fund an account through them we may receive a referral reward at no cost to you; it never affects our tools or conclusions. This is educational information, not investment advice — choose the broker that best fits your needs.