Risk of Ruin Calculator
See the mathematical probability of blowing up your account at your current risk-per-trade — and find the risk level that keeps you alive.
Enter Your Trading Stats
Ruin Probability Across Risk Levels
Frequently Asked Questions
What is risk of ruin?
The probability that a string of losses wipes out your trading capital, given your win rate, payoff ratio and position size. Even profitable strategies can hit 100% ruin if you risk too much per trade.
What is an acceptable risk of ruin?
Professional traders target under 1%. Anything above 5% is dangerous; above 20% means blowing up is a matter of time, not luck.
Why does risk per trade matter so much?
Ruin grows exponentially with position size. Doubling risk from 2% to 4% far more than doubles your chance of ruin — the math punishes oversized bets brutally.
Can a losing strategy ever survive?
No. If your edge is zero or negative, risk of ruin is 100% regardless of position size. Fix the strategy first, then size positions.