Kelly Criterion Options Sizing Calculator
Kelly-optimal fraction for a defined-risk options trade from win rate and payoff ratio — plus the half-Kelly the pros actually use.
Formula
Full Kelly maximizes long-run growth but suffers brutal drawdowns and assumes you know p and b exactly — you don't. Half-Kelly gives ~75% of the growth at half the variance, which is why practitioners size there or below.
Not financial advice — for informational and analytical use only. Verify all figures with a qualified professional before acting on them.
Need kelly criterion options sizing calculator results fast? Analysts, founders, traders and finance professionals use the Kelly Criterion Options Sizing Calculator to skip the spreadsheet and get a defensible answer in one step — free, private and instant.
About Kelly Criterion Options Sizing Calculator
Kelly-optimal fraction for a defined-risk options trade from win rate and payoff ratio — plus the half-Kelly the pros actually use. Full Kelly maximizes long-run growth but suffers brutal drawdowns and assumes you know p and b exactly — you don't. Half-Kelly gives ~75% of the growth at half the variance, which is why practitioners size there or below. The governing relationship is f* = (p·b − q)/b, b = win/loss ratio. The Kelly Criterion Options Sizing Calculator computes entirely in your browser — free, private (your figures never leave your device) and instant, recalculating live as you change any input.
How to use Kelly Criterion Options Sizing Calculator
- 1Enter Win probability (%), Average win, Average loss, Account size (currency) into the Kelly Criterion Options Sizing Calculator.
- 2The result is computed automatically using f* = (p·b − q)/b, b = win/loss ratio — there is no button to press.
- 3Change any input to model a different scenario, then copy or share the result.
Why use Kelly Criterion Options Sizing Calculator?
- ✓Computes kelly criterion options sizing calculator instantly with the correct formula — no spreadsheet needed
- ✓100% free and unlimited, with no sign-up, login or paywall
- ✓Runs entirely in your browser, so the figures you enter stay private
- ✓Shows the formula, a live worked example and references so you can defend the number
Frequently asked questions
What is the formula behind the Kelly Criterion Options Sizing Calculator?+
Kelly Criterion Options Sizing Calculator uses f* = (p·b − q)/b, b = win/loss ratio. Full Kelly maximizes long-run growth but suffers brutal drawdowns and assumes you know p and b exactly — you don't. The tool substitutes your actual inputs into this relationship and shows the worked example step by step.
What inputs does the Kelly Criterion Options Sizing Calculator need?+
Enter Win probability (%), Average win, Average loss, Account size (currency) and the result updates immediately — there is no button to press. Change any value to model a different scenario in real time.
Is the Kelly Criterion Options Sizing Calculator free, and is my data private?+
Yes — it is completely free with no sign-up or usage limit, and it runs entirely in your browser, so the numbers you enter are never uploaded or stored on any server. It is for informational and analytical use, not financial advice.
What should I watch out for when using the Kelly Criterion Options Sizing Calculator?+
Half-Kelly gives ~75% of the growth at half the variance, which is why practitioners size there or below.
What is the Kelly Criterion Options Sizing Calculator based on?+
The method follows authoritative sources: Kelly (1956); Thorp — The Kelly capital growth criterion. The formula and references are shown on the page so you can verify and cite the result.
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