Kelly Criterion Calculator
There’s actual mathematical formula that tells you the perfect amount to bet based on your edge. Yes, real mathematics, not just vibes. Professional gamblers swear by this.
What It Does: Uses probability and odds to calculate what percentage of your bankroll you should bet. It maximizes your long-term growth while minimizing your risk of going broke. It’s literally the formula casinos fear.
Why This is Different: Most people bet random amounts. ₦1,000 today, ₦5,000 tomorrow, ₦500 next week. No strategy. Kelly Criterion says “based on your bankroll and your edge, bet exactly this percentage.” It’s systematic. It’s scientific. It works.
How to Use It:
- Enter your total bankroll (all the money you have for betting, like ₦50,000)
- Enter the odds you’re getting (like 2.50)
- Enter YOUR assessment of win probability (this is the hard part, be honest)
- Choose your Kelly fraction (Full Kelly, Half Kelly, or Quarter Kelly)
📊 Kelly Criterion
Calculate the optimal bet size based on your edge
The odds you’re getting on the bet
Your estimated chance of winning (based on your analysis)
Most pros use Half Kelly to reduce volatility
The Secret Sauce: The key is the probability estimate. If the bookie’s odds say 40% chance but YOU genuinely think it’s 60% chance, that’s your edge. The bigger your edge, the more Kelly tells you to bet. No edge = don’t bet at all.
Real Example: You have ₦100,000 bankroll. You found a bet at 2.50 odds. The implied probability is 40% but based on your research, you believe it’s 50%. You input this. Kelly says bet 8% of your bankroll = ₦8,000. That’s your optimal stake.
The Three Options:
- Full Kelly: Aggressive, fastest growth, but volatile
- Half Kelly (recommended): More conservative, still good growth, less stress
- Quarter Kelly: Super safe, slow growth, for people who can’t handle swings
Honest Warning: Kelly only works if your probability estimates are accurate. If you’re just guessing or being overconfident, this will just help you lose money faster. Be brutally honest with yourself. If you’re not sure, don’t use Full Kelly, use Half or Quarter.
Why Pros Use This: Because it prevents betting too much (which leads to ruin) and betting too little (which means missed growth). It’s the Goldilocks zone of bet sizing. Over months and years, this strategy compounds your bankroll properly.