Risk of Ruin Calculator
The probability your strategy hits its ruin point before its edge saves it. Small edges at big position sizes have ugly answers, which is the entire argument for small risk.
Results (live)
Estimates only, not financial advice. All math runs in your browser; nothing you type leaves this page.
How it works
approximation: RoR ≈ ((1−p)/(p×b))^(threshold ÷ risk per trade)
Worked example
50% wins at 1.5:1 risking 2% with a 50% ruin line: risk of ruin ~0.004%. Triple the risk to 6% and the same strategy's ruin odds jump above 3%: same edge, deadlier sizing.
FAQ
Why does halving risk-per-trade help so much?
Ruin odds fall exponentially with the number of losing units you can absorb. Halving risk doubles the units and squares your survival odds.
Is this exact?
It is a standard approximation assuming fixed fractional bets and stable stats. Real trading varies, so read it as an order of magnitude.
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Estimates only, not financial, tax or investment advice. Verify numbers against your exchange or a professional before acting.