Kelly Criterion Calculator

Bankroll-aware stake sizing for +EV bets. Full Kelly maximizes growth; quarter Kelly smooths the ride. The dashboard AI adjusts the fraction by edge confidence.

Kelly Criterion Calculator
Bankroll-aware sizing for +EV bets.

Most pros use quarter or half Kelly to reduce variance.

Recommendation
Recommended stake
Full Kelly %
Adjusted %
Edge over book

Kelly maximizes long-run growth, but full Kelly is volatile. If the formula returns negative, the bet has no edge. Pass.

Kelly is brittle. Confidence weighting fixes that.

Full Kelly assumes your win probability is exactly right. The dashboard AI grades that confidence and scales the stake accordingly.

Confidence-weighted fraction

Each fair price gets an AI confidence score from 0 to 100 based on sharp-book agreement and historical accuracy. Higher confidence unlocks a larger Kelly fraction; lower confidence pulls it down.

Drawdown simulator

Before you commit to full Kelly, the dashboard runs a 1,000-trial Monte Carlo on your bankroll trajectory. See the 5th-percentile drawdown for full, half, and quarter Kelly side by side.

Edge-decay alerts

Kelly fades fast as the line moves. The AI tracks the edge in real time and notifies you when it has decayed below your threshold so you can size down or skip.

Per-bet sizing log

Every Kelly recommendation is logged with the fair price, book price, and confidence score. Review your sizing decisions weekly and tune your default Kelly fraction to your stomach.

Frequently asked questions

Kelly Criterion is a stake-sizing formula that maximizes the long-run growth rate of a bankroll. Given a fair win probability and the book payout, it returns the fraction of bankroll to risk on each bet.

Full Kelly is mathematically optimal but volatile. A 30% drawdown is normal at full Kelly. Most pros use quarter or half Kelly to smooth variance and survive estimation error in their fair-probability inputs.

Kelly assumes you know the true probability. The dashboard AI scores each fair-line input with a confidence band based on sharp-book agreement and edge stability. Lower confidence = lower automatic Kelly fraction.

Negative Kelly means the book line implies a higher probability than your fair price. Pass on the bet. The calculator caps the recommended stake at $0 in this case.

Kelly works for parlays only when you can credibly estimate the combined fair probability. Variance is much higher, so most parlay bettors use a much smaller fraction (one-eighth Kelly) or fixed-unit sizing.

Sized correctly, every time

The dashboard layers Kelly on top of the live +EV feed and your bankroll, so every recommended stake is already sized for you.