Quarter Kelly
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Most conservative.
Inputs
Use your win rate and average payoff ratio.
Enter assumptions, then calculate a sizing range.
Sizing view
Read full Kelly first, then compare calmer bands.
Waiting for a valid edge
--
A positive Kelly fraction appears when the assumed edge turns positive.
Half Kelly
--
Balanced reference.
Full Kelly
--
Maximum growth case.
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 uses only your win rate and average profit / loss ratio. It returns full, half, and quarter Kelly references. It does not estimate the 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.
Quick guide
Use cases, answers, and nearby tools
Compact below-tool notes that help first-run users and repeated visitors move faster without changing the main interface.
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How to use
Run a clean first pass
- Enter win probability and average profit / loss ratio.
- Calculate the edge and compare quarter, half, and full Kelly sizing bands.
- Use the spectrum and result notes to sanity-check how aggressive the fraction feels.
Examples
Real jobs this page helps with
- Trade plan sizingCompare how a 55 percent setup at 1.8R changes across quarter, half, and full Kelly references.
- Risk discussionShow a teammate why fractional Kelly is often calmer than using the theoretical maximum size.
FAQ
What people usually want to know
Does it estimate win rate for me?
No. You provide the edge assumptions, and the page returns sizing references from those inputs.
Should I always use full Kelly?
Not necessarily. Many users treat half or quarter Kelly as a calmer reference when edge estimates are noisy.
Is any market data required?
No. This is a static local calculator driven entirely by your inputs.