How this calculator works
Average cost basis is calculated by dividing the total amount invested by the total number of shares owned. This gives you the effective break-even price per share before fees and taxes.
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Stock Average Calculator
Free stock average calculator to estimate your average cost basis after multiple share purchases at different prices.
Instant result
Average cost basis
$91.00
Total shares25
Total invested$2,275.00
Break-even share price$91.00
Calculator results are provided for planning and educational purposes. For taxes, legal decisions, lending, or medical advice, verify the numbers with an official source or qualified professional.
About this calculator
This stock average calculator helps investors understand their average purchase price when they buy the same stock more than once. It is especially helpful for dollar-cost averaging and planning future buys.
How to use it
- Enter the shares and purchase price for your first buy.
- Enter the shares and purchase price for your second buy.
- Review the combined average cost basis and total invested amount.
- Use the result to estimate break-even price or future portfolio scenarios.
Example
If you bought 10 shares at $100 and 15 shares at $85, your average price becomes lower than your original entry price.
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Stock Average Calculator formula
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How to use this calculator
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Use cases and scenarios
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Stock Average Calculator for $5 first purchase shares
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Stock Average Calculator for $10 first purchase shares
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Stock Average Calculator for $20 first purchase shares
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Frequently asked questions
Does this include trading fees?
No. This simplified version does not include brokerage commissions, taxes, or dividend reinvestment details.
Why does average cost matter?
It helps you understand your break-even level and how additional purchases affect your position.
Can I use this for ETFs?
Yes. The same average cost concept works for stocks, ETFs, and other securities bought in multiple transactions.