Investing & Wealth

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.

Stock Position Size & Risk Calculator Results

0

Position Size (Shares)

  • Dollar Risk per Trade —
  • Total Capital Deployed —
  • Risk per Share —

What This Means

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

  1. Enter Total Trading Account Equity
    Input total portfolio cash and equity.
  2. Enter Risk Percentage (%)
    Select maximum risk per trade (typically 1% to 2%).
  3. Enter Entry Price & Stop Loss Price
    Input planned buy price and stop-loss exit level.
  4. 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

The 1% rule states that a trader should never risk more than 1% of their total account equity on any single trade, ensuring survival during consecutive losing streaks.

It multiplies your account equity by the risk percentage to get the dollars at risk, divides that by the per-share risk (the distance between entry and stop-loss), and rounds down to whole shares. Multiplying the shares by the entry price gives the capital deployed.

It is the absolute difference between your entry price and your stop-loss price — how much you would lose per share if the stop is hit. The calculator uses it as the divisor when turning your dollar risk into a share count.

Account equity above zero, an entry price above zero, and a stop-loss that differs from the entry price. If the stop equals the entry the per-share risk is zero, so the calculator stops with 'Stop-loss must differ from entry price.'

Rounding down keeps the actual dollar risk at or below your chosen limit. Rounding up could push the loss beyond the risk budget if the stop is hit, so the calculator floors the share count.

Free to use, no account needed. Calculations run in your browser, so nothing you type is sent to a server. Results are estimates — how we build and check our calculators.

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Next step: browse the full Investing & Wealth calculators or read the related guides for context before you decide.