How is required capital computed from a dollar stop?

Divide the dollar risk (stop distance × dollar-per-point × contracts, or any stated dollar risk) by the chosen risk percent. The result is the account size at which that dollar risk equals that percent.

Does more capital always lower risk of ruin?

Only if dollar risk stays fixed, so that risk percent falls. If dollar risk scales with capital, risk percent is unchanged and the lives count is unchanged.

Does this tell me how much capital to fund?

No. It reports the inversion of percent-risk arithmetic for numbers you enter. It does not instruct a deposit.

Calculators

Capital required for a strategy

If the dollar amount risked per trade is fixed (a stop in dollars) and the risk percent is a choice, the account size that makes those two consistent is dollar risk ÷ risk percent. The widget then runs that book against a stated floor.

Max Drawdown in this widget is a static floor from starting balance (v1) — a fixed floor measured from your starting balance, not a floor that ratchets upward with a new equity peak. Implied capital is dollar-risk arithmetic; simulated survival still uses this static floor.

Account size in the widget is an input. The table is the inversion: capital = dollar risk ÷ risk%.

Open the full tool — free

Same engine at the same free accuracy — save a rule set, add a stop, or import a history. The stamped file is written after that run, not from this typed-average result.

The mechanism

$250 at 1% implies capital = $250 ÷ 1% = $25,000. At a 10% total-drawdown allowance, lives = 10% ÷ 1% = 10.

Quantity	Formula	Value
Implied capital	dollar risk ÷ risk%	$25,000
Lives at 10% allowance	drawdown% ÷ risk%	10

Contracts still round down; see position sizing methods. This page does not pick a size. It reports the capital that matches a stated dollar risk and a stated percent.

What the widget adds

The identity does not know win rate. The widget does: it counts simulated sequences on the book you enter. The free personal-rule engine currently models a stated Max Drawdown allowance as a fixed floor measured from your starting balance, not a floor that ratchets upward with a new equity peak.

Position sizing calculator · methodology.

FAQ

How is required capital computed from a dollar stop?: Divide the dollar risk (stop distance × dollar-per-point × contracts, or any stated dollar risk) by the chosen risk percent. The result is the account size at which that dollar risk equals that percent.
Does more capital always lower risk of ruin?: Only if dollar risk stays fixed, so that risk percent falls. If dollar risk scales with capital, risk percent is unchanged and the lives count is unchanged.
Does this tell me how much capital to fund?: No. It reports the inversion of percent-risk arithmetic for numbers you enter. It does not instruct a deposit.

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<iframe
  src="https://propsurvival.com/embed/personal-rules?src=embed-capital-required-for-strategy"
  width="100%"
  height="700"
  style="border:0"
  loading="lazy"
  title="Capital-required calculator — PropSurvival">
</iframe>
<p class="ps-attribution" style="margin:6px 0 0;font:11px system-ui,-apple-system,sans-serif;color:#82857F">Data: <a href="https://propsurvival.com/research/prop-firm-rules-census-2026?utm_source=embed&utm_medium=widget&utm_campaign=atif" target="_blank" rel="noopener">PropSurvival prop-firm rules census</a> · CC BY 4.0</p>

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Paste on your own page — the pasted block includes a crawlable attribution link to the CC BY 4.0 PropSurvival firm-rules census (the license's attribution condition, not a courtesy — keep it visible), plus the in-widget via PropSurvival link. Loads are counted as first-party /e/ beacons only — no third-party analytics.

Run it against your own numbers

The same engine, unlimited runs, at the same free accuracy as this page's calculator — open the full personal rule editor to save a rule set, add a profit goal or daily loss stop, or import a trade history.

Open the personal rule editor — free, full accuracy →

Rules and outcomes vary by firm and by trader; nothing on this page is investment or trading advice, and PropSurvival is not affiliated with, endorsed by, or sponsored by any prop trading firm. This calculator models a stated rule set — it does not predict market outcomes.