Forex Risk of Ruin Calculator
See the estimated chance of losing your whole account based on your win rate, reward-to-risk ratio, and how much you risk per trade. Tune the inputs to find a position size your strategy can actually survive.
Share of trades you historically close in profit.
How many times your risk you make on a winning trade, from your usual stop-to-target distance.
Percent of your account risked on a single trade's stop-loss.
At a 45% win rate with a 1.3 reward-to-risk ratio and 10% risk per trade, you have roughly a 1-in-2 chance of losing the full account over a long run of trades.
For educational purposes only. Read our risk warning before trading.
How risk of ruin is estimated
First we find your per-trade edge from win rate (w) and reward-to-risk (R): a win adds R units of your risk, a loss costs your full risk amount. With a positive edge, we model the account as a fixed number of risk units and apply the classic gambler's-ruin formula. A negative or zero edge means ruin is effectively certain over enough trades.
Break-even win rate by reward-to-risk
| Reward-to-risk | Break-even win rate | What a positive edge needs |
|---|---|---|
| 1.0 | 50.0% | Win more than 50.0% of trades |
| 1.5 | 40.0% | Win more than 40.0% of trades |
| 2.0 | 33.3% | Win more than 33.3% of trades |
| 2.5 | 28.6% | Win more than 28.6% of trades |
| 3.0 | 25.0% | Win more than 25.0% of trades |
Unlike a fixed payout, a reward-to-risk ratio above 1 lowers the win rate you need to break even — the trade-off most trend and swing systems lean on instead of a high hit rate.
Frequently Asked Questions
It is the estimated probability of losing your entire account over a long sequence of trades, given your edge and bet size. It is a historical-style projection, not a prediction of any single session.
Forex trades don't have a fixed payout the way binary options or fixed-odds bets do — what a winner nets you depends entirely on where you placed your stop and your target. The reward-to-risk ratio (reward ÷ risk) plays exactly the role a payout plays in the ruin formula: it's how many units you gain on a win for the one unit you lose. A 2:1 target-to-stop distance is a reward-to-risk of 2, and the model treats it the same way either input would be treated.
Smaller stakes mean more risk units in your account, which the formula raises to a higher power. Even a real edge can be wiped out by a losing streak if each trade risks too much capital.
If your win rate and reward-to-risk ratio produce a zero or negative per-trade edge, no position size can protect the account over time, so the model reports a 100% risk of ruin. A reward-to-risk above 1 lowers the win rate you need to clear that bar — the trade-off most trend and swing systems lean on.
Many traders aim to keep it in the low single digits by combining a real positive edge with small per-trade risk. There is no level that removes risk entirely from leveraged trading.
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