Free tool
Risk of ruin calculator
The probability of blowing up your account, simulated.
Risk of ruin (−50%)
92.8 %
Expectancy / trade
-0.01 R
Median return
-33.8 %
Monte-Carlo simulation (5,000 runs, fixed-fractional). Lowering risk per trade is the most powerful lever to cut the risk of ruin.
Risk of ruin is the probability that your account drops by a fatal percentage (often 50%) before it thrives. It depends on your win rate, your reward/risk ratio and, above all, your risk per trade. Two systems with the same expectancy can have very different risks of ruin depending on their sizing. This calculator runs a Monte-Carlo simulation to estimate that probability — the best reminder that risking too much per trade can ruin even a winning strategy.
Go from calculation to proof
These numbers are estimates. On GetBacktest, backtest your strategy tick by tick on real data and get a true robustness verdict.
Backtest for freeFrequently asked questions
What is risk of ruin?
The probability that your capital falls below a critical threshold (ruin drawdown) over a given horizon, despite a sometimes-positive expectancy.
How do I reduce it?
The most powerful lever is lowering the risk per trade. Improving the win rate and reward/risk ratio helps too, but sizing dominates.
Is the calculation reliable?
It's a Monte-Carlo estimate (fixed-fractional). Reality has streaks and shifting volatility: a backtest on real data remains essential.
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