Stock Average Calculator
Stock Average Calculator
Calculate your average cost per share when you buy a stock at different prices over time. Add up to five purchases to see your weighted average cost basis, total shares, and total investment.
Purchase Details
Results
INSTRUCTIONS
How to Use This Calculator
1. Enter First Purchase
Type the number of shares and price per share for your first stock purchase. This is your initial position.
2. Add More Purchases
Click "Add Purchase" to enter additional buys. You can add up to five separate purchase entries.
3. See Your Average
The calculator instantly computes your weighted average cost per share as you enter or update values.
4. Evaluate Your Position
Compare your average cost to the current market price to determine if you are in a profit or loss position.
EDUCATION
Understanding Average Cost Basis
Your average cost per share is the weighted average price you paid across all of your purchases of the same stock. This number is critical because it determines whether you are sitting on a profit or a loss at any given market price. Brokers often call this your "cost basis."
The formula is: Average Cost Per Share = Total Amount Invested / Total Shares Owned. For example, if you buy 100 shares at $50 and then 50 more shares at $45, your total investment is $7,250 and you own 150 shares. Your average cost per share is $7,250 / 150 = $48.33.
This strategy of buying additional shares at a lower price is commonly known as "averaging down." It reduces your overall cost basis so the stock does not need to recover as much for you to break even. However, averaging down also increases your exposure to the same stock, so it should be used with a clear plan and proper risk management.
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