Stock Average Calculator
Calculate your average cost basis across multiple stock purchases. Add each buy transaction to see your weighted average price per share, total investment, and break-even point. Optionally enter the current market price to see your unrealized profit or loss.
Updated
Educational purposes only.
This calculator is for educational purposes only. It does not account for dividends, stock splits, or tax implications. Consult a financial professional for investment decisions.
Educational purposes only. These calculators illustrate concepts and do not constitute investment advice. Read our disclaimer
StockCram is not a broker-dealer, investment adviser, or financial institution. All content is for educational and informational purposes only and should not be construed as personalized investment advice. Consult a qualified financial professional before making investment decisions. Past performance does not guarantee future results.Embed this calculator on your site
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<p style="font-size:12px">
<a href="https://www.stockcram.com/tools/calculators/stock-average-calculator" target="_blank" rel="noopener">Stock Average Calculator</a>
by <a href="https://www.stockcram.com" target="_blank" rel="noopener">StockCram</a>
</p>How It Works
Enter your purchase lots
Add each purchase with the number of shares and price per share.
Add more lots as needed
Click "Add Lot" to include additional purchases at different prices.
Enter current market price (optional)
Add the current stock price to see your unrealized profit or loss.
See your average cost basis
View your weighted average price, total shares, total invested, and P/L breakdown.
Frequently Asked Questions
The average cost basis (also called average price per share) is the weighted average price you paid across all your purchases of a particular stock. It is calculated by dividing the total amount invested by the total number of shares purchased. This is your break-even price — the stock must trade above this for you to be profitable.
Averaging down means buying more shares of a stock after its price has dropped. This lowers your overall average cost basis, making it easier to break even or profit when the price recovers. For example, if you bought 100 shares at $50 and then 100 more at $40, your average cost drops from $50 to $45 per share.
Averaging down lowers the price at which a position breaks even, but it also increases the amount invested in a stock that has already fallen. If the decline continues, the larger position loses more.
Multiply each purchase quantity by its price to get the cost per lot. Add all lot costs together for your total investment. Add all shares together for your total shares. Divide total investment by total shares. For example: 100 shares at $50 ($5,000) + 50 shares at $40 ($2,000) = $7,000 total ÷ 150 shares = $46.67 average.
Dollar-cost averaging (DCA) involves investing a fixed dollar amount at regular intervals regardless of price. Averaging down specifically means buying more shares after a price decline. DCA is a systematic strategy that naturally buys more shares when prices are low, while averaging down is a deliberate decision made in response to falling prices.
This calculator focuses on the price-based cost average and does not factor in dividends received. Dividends effectively reduce your cost basis for tax purposes. If you reinvest dividends (DRIP), those additional shares would be separate lots with their own cost basis.
You can add up to 20 separate purchase lots. Each lot represents a different buy transaction with its own number of shares and price per share. This covers most individual stock position histories.