Stock Position Size & Risk Calculator
Calculate exact share position size based on account size, maximum dollar risk (1% to 2%), entry price, and stop-loss level.
What this calculator does
The Stock Position Size & Risk Calculator estimates your result instantly from the values you enter, using standard investing & wealth formulas. Calculate exact share position size based on account size, maximum dollar risk (1% to 2%), entry price, and stop-loss level. Calculations run in your browser, so nothing you type is sent to a server, and the output is an estimate for planning rather than financial advice.
About Stock Position Size & Risk Calculator
The Stock Position Size Calculator implements professional risk management by calculating the exact number of shares to buy so that if your stop-loss is hit, you only lose your predefined allowable risk amount (e.g. 1% of total account).
Formula & Mathematical Calculation
Dollar Risk per Trade = Account Equity × ( Risk Percentage % / 100 )
Risk per Share ($) = Entry Price - Stop Loss Price
Position Size (Number of Shares) = Dollar Risk per Trade / Risk per Share
Calculation Example
$50,000 Account (1% Risk = $500 max risk): Entry Price: $120 | Stop Loss: $115 ($5 risk/share) → Position Size = 100 Shares ($12,000 total capital). If stopped out at $115, loss is exactly $500.
Key Benefits
- Calculates exact share quantity to buy based on strict risk management rules
- Prevents catastrophic portfolio losses by enforcing stop-loss discipline
- Calculates Risk-to-Reward Ratio (e.g. 1:3)
- Essential for day traders, swing traders, and active equity investors
- 100% free trading tool
How to Use this Calculator
-
Enter Total Trading Account Equity
Input total portfolio cash and equity. -
Enter Risk Percentage (%)
Select maximum risk per trade (typically 1% to 2%). -
Enter Entry Price & Stop Loss Price
Input planned buy price and stop-loss exit level. -
Calculate Position Size
Click Calculate to view exact shares to purchase.
Assumptions & Limitations
What the calculation assumes
- Every value you enter is treated as an exact, known amount.
- Rates and contributions are assumed to stay constant for the whole period unless the form asks for them separately.
- Results use standard financial formulas and ignore fees, penalties and promotional terms that are not entered above.
- Inflation, tax changes and market volatility are not modelled unless a field for them is provided.
- Amounts are unit-agnostic: results are returned in the same currency you enter.
What it does not cover
- Stock Position Size & Risk Calculator produces estimates for education and planning, not a quote, offer or professional advice.
- Real-world outcomes differ when fees, taxes, rounding rules or provider-specific terms apply.
- Local regulations and tax rules vary by country and change over time; verify current rules for your jurisdiction.
- Figures are only as accurate as the inputs you supply — check them before acting on the result.
- For decisions with lasting financial impact, confirm the numbers with a qualified professional.
Frequently Asked Questions
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