Stock Average Calculator

In volatile stock markets, buying shares of individual companies or funds rarely happens in a single transaction. Instead, long-term investors build their positions over time, purchasing extra shares of a stock at different price levels as the market fluctuates. To evaluate your positions accurately, you must find your Weighted Average Cost Per Share.

The Mathematics of Weighted Averages

Many investors make the mistake of averaging buy prices directly (e.g., adding $150 and $110 to find an average price of $130). However, this fails to account for the number of shares bought in each transaction. To find your true weighted average cost per share, use the following formula: $\text{Average Cost} = \frac{\text{Total Cost Basis}}{\text{Total Accumulated Shares}} = \frac{(P_1 \times S_1) + (P_2 \times S_2)}{S_1 + S_2}$ Where:

• P represents your purchase price per share.
• S represents your share count.

For example, buying 100 shares at a purchase price of $150 and 150 shares later at a lower purchase price of $110:

• Your total cost basis is: $\text{Basis} = ($150 \times 100) + ($110 \times 150) = $31,500$
• Your total accumulated shares are: $\text{Shares} = 100 + 150 = 250 \text{ shares}$
• Dividing these yields an average cost of $126.00 per share (revising your cost down from the direct average of $130).

This tool calculates these weighted averages clearly, helping you plan your path out of losing investments.

The Power of Averaging Down

• Dollar-Cost Averaging Down: Buying more shares of a company after its price drops lower than your first buy order. This reduces your average cost per share, allowing you to hit break-even and lock in profits faster when the stock price recovers.
• The Core Risk: Averaging down on a failing company with deteriorating business models can lead to serious losses. Investors must ensure that the company's fundamentals remain strong before allocating extra capital to a dropping stock.

Our tool helps you analyze your weighted averages, helping you make smart investing decisions.