Risk of Ruin Calculator
Calculate the probability of losing your entire betting bankroll based on your win rate, odds, and bet sizing strategy. Essential for long-term bankroll survival.
Betting Parameters
Your total betting bankroll
Amount per bet (2.0% of bankroll)
Your historical win percentage
Average odds you bet at
Risk Analysis
Understanding Risk of Ruin
What is Risk of Ruin?
Risk of Ruin is the probability of losing your entire betting bankroll before achieving your profit goals. It's a fundamental concept in bankroll management that helps bettors understand their survival probability given their betting strategy.
The Gambler's Ruin Problem
This calculator uses principles from the classical "Gambler's Ruin" problem in probability theory. Even with a positive edge, improper bet sizing can lead to ruin due to variance and losing streaks.
Key Factors Affecting Risk
- Unit Size: Larger bets relative to bankroll increase risk dramatically
- Win Rate: Higher win rate reduces risk, but edge matters more
- Odds: Higher odds increase variance and potential for large swings
- Edge: Positive expected value is crucial for long-term survival
- Number of Units: More units = lower risk (smaller percentage per bet)
Safe Bankroll Management Guidelines
- Conservative: Risk of Ruin below 1% (50+ units, 2% per bet or less)
- Moderate: Risk of Ruin 1-5% (25-50 units, 2-4% per bet)
- Aggressive: Risk of Ruin 5-15% (15-25 units, 4-7% per bet)
- Dangerous: Risk of Ruin above 15% (high likelihood of losing bankroll)
The Importance of Edge
Without a positive edge (expected value > 0), risk of ruin is 100% over a long enough timeline. No amount of bankroll management can overcome negative expected value. Calculate your edge: Edge = (Win Rate × Odds) - 1
Pro Tip: Even profitable bettors experience significant drawdowns. Aim for a Risk of Ruin below 5% to ensure long-term bankroll survival. If your risk exceeds 15%, reduce your unit size immediately. Use the Kelly Criterion (or fractional Kelly) for optimal bet sizing.
Warning: This calculator assumes consistent bet sizing and win rate. Real betting involves variance, and actual risk may differ. Always bet responsibly and never risk money you cannot afford to lose.