Quarter Kelly
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Most conservative reference for users who want more variance buffer.
Inputs
Enter win rate and average profit / loss ratio.
Enter your assumptions, then calculate a sizing range.
Sizing view
Read the full Kelly fraction first, then compare the calmer bands.
Waiting for a valid edge
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A positive Kelly fraction appears when the assumed edge turns positive.
Half Kelly
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Often used when the edge estimate is noisy or confidence is moderate.
Full Kelly
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Theoretical maximum growth fraction under the Kelly assumptions.
Risk temperature
Sizing spectrum
The marker stays near calm or pushes toward assertive sizing depending on the Kelly fraction.
Waiting for a scenario
What the calculator assumes
This tool expects two inputs: how often you win and how large the average winner is versus the average loser. It returns full, half, and quarter Kelly references. It does not estimate your edge for you, and it does not replace account-level risk limits.
Examples: compare a 55% setup at 1.8R, sanity-check a discretionary trade plan, or explain fractional Kelly sizing to a teammate.
FAQ: This calculator runs locally and does not forecast win rate for you. Use it as a sizing reference alongside account-level risk limits and drawdown rules.