- Use it when you need a quick decision-ready view for Position Sizing + Kelly.
- Use it when you want to understand the formula and inputs before switching to the interactive tool.
- Use it when comparing investment, loan, or capital allocation scenarios.
- Capital
- Risk per Trade (%)
- Entry Price
- Stop Price
Example inputs
- Win probability: 55%
- Average win: 12%
- Average loss: 8%
Formula logic
Risk position size = capital x risk per trade / risk per unit. Kelly fraction = win rate - loss rate / reward-risk ratio.
How to read the result
Kelly output is aggressive. Many investors use half-Kelly or quarter-Kelly because win-rate estimates are noisy.
- Treating estimated win rate as certain.
- Using full Kelly with correlated positions.
- Ignoring maximum drawdown tolerance.
Risk-based position size and Kelly fraction. This page explains the main inputs and output interpretation before you switch into the full calculator.
Use the interactive tool when you already know your assumptions and want detailed tables, charts, or CSV export.
The formula uses the following inputs: Capital, Risk per Trade (%), Entry Price, Stop Price. Enter them in the calculator above to get precise results.
Yes, The Capital Deck's Position Sizing + Kelly is completely free with no sign-up required.
Yes, the calculator works on all modern browsers on desktop and mobile devices.
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