Kelly Criterion Calculator
The Kelly criterion is a formula for sizing bets to maximise the long run growth of your bankroll. It balances edge against odds: the bigger your advantage and the higher the payout, the more you should stake, but never so much that a losing streak wipes you out. This calculator takes your estimated win probability and the odds on offer, then returns the full Kelly stake as a percentage of your bankroll along with a half Kelly and quarter Kelly, which many bettors prefer because they smooth out variance. If the edge is negative it will tell you not to bet at all. Enter your numbers to see the recommended stake in both percent and money terms. All math runs in your browser.
How to use Kelly Criterion Calculator
- Enter your estimated win probability.
- Enter the odds in decimal or American.
- Read the suggested bankroll fraction and apply a fractional multiplier if you want.
Frequently asked questions
What does the Kelly criterion output?
It returns the fraction of your bankroll that mathematically maximizes long-run growth given your win probability and the odds; it is a sizing formula, not advice to bet.
How is the Kelly fraction computed?
It uses the edge divided by the odds, specifically the win probability times decimal odds minus one, all over decimal odds minus one.
Why do many use fractional Kelly?
Full Kelly can swing a bankroll sharply, so half or quarter Kelly reduces volatility; the tool can scale the result to a chosen fraction for that reason.
What is Kelly Criterion Calculator?
The Kelly criterion is a formula for sizing bets to maximise the long run growth of your bankroll. It balances edge against odds: the bigger your advantage and the higher the payout, the more you should stake, but never so much that a losing streak wipes you out.
Is Kelly Criterion Calculator free to use?
Yes. Kelly Criterion Calculator is completely free, with no sign-up and no usage limits.
Does Kelly Criterion Calculator work in a web browser?
Yes. Kelly Criterion Calculator runs in any modern web browser. There is nothing to download or install.
Is my data private with Kelly Criterion Calculator?
Yes. Kelly Criterion Calculator runs entirely on your device in your browser, so nothing you enter is uploaded to a server.
Badge
Link this tool from a README, doc or site. The badge links back to this page.
[](https://yourhack.ai/kelly-criterion-calculator)