Kelly tells you the ceiling, not the answer.
The Kelly criterion sizes a bet from win rate and payoff ratio alone. It is also famously aggressive when the inputs are even slightly wrong, which every trading edge estimate is.
Kelly fraction (f*)
Positive Kelly fraction. Most traders should risk a fraction of this, not the full amount.
The tool should change the next decision, not just return a number.
Each free tool is built as a small diagnostic. It gives the visitor a usable result, then points them toward the cockpit workflow where the same idea becomes saved history and review discipline.
Kelly fraction (f*)
Use the output as a review prompt, not a signal.
- Formula: f* = (b·p − q) / b — the fraction of capital to risk per trade that maximizes long-run geometric growth.
- Full Kelly is aggressive and assumes the inputs are exact. Most traders use a fraction of f*: 1/4 Kelly (25% of f*) or 1/2 Kelly (50% of f*) trade off some growth for much less drawdown.
- Negative f* means there is no edge at this payoff ratio — the correct size is zero, not a smaller positive number.
Risk disclosure
This tool is educational. It does not place trades, recommend trades, or know your personal financial situation. Futures trading involves substantial risk of loss.
Reviewed as educational research, not trade advice.
- Author
- Nexural Research Desk
- Reviewer
- Nexural Risk & Automation Review
- Updated
- 2026-05-28
- Primary query
- kelly criterion calculator
The free page is the front door. The cockpit is the operating system.
Free visitors should leave with value even if they never pay. When they want history, AI review, premium desks, or automation context, the dashboard becomes the next logical step.
The dashboard turns calculator output into a repeatable review workflow.
Conversion happens after demonstrated intent, not before value.