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Stake the right amount
with the Kelly Criterion

The Kelly Criterion is a formula for how much of your bankroll to bet, based on the price and your chance it wins. Enter your bankroll, the odds and your chance. Pick half or quarter Kelly for smaller, steadier bets.

Kelly stakeFree · No sign-up
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Recommended stake
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% of bankroll
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Full Kelly %
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Your chance vs price
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Kelly fraction = (b·p − q) ÷ b, where b = decimal odds − 1. A result below zero means the price pays too little, so skip it.

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Our model gives each game its own chance to win and checks it against the price. The free picks show the price and what $10 returns.

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How to use it

  1. Enter the bankroll you're betting with.
  2. Enter your honest chance it wins, not your hope.
  3. Add the odds in decimal, American or fractional.
  4. Choose half or quarter Kelly to soften the swings.

Worked example

Bankroll$1,000
Win chance55%
Odds2.00
Full Kelly10.0%
Half-Kelly stake$50.00

Kelly:
quick answers

What is the Kelly Criterion?

A formula that tells you what share of your bankroll to bet, based on the price and your chance it wins: fraction = (b·p − q) ÷ b.

Full, half or quarter Kelly?

Half or quarter Kelly means smaller bets. Your bankroll swings less, and a small mistake in your chance hurts less.

What if the price is too short for my chance?

If the formula returns zero or less, the price pays too little for your chance. The right stake is nothing, so skip it.

Bet Better is not a bookmaker and does not accept wagers. Tools are for information only. Gamble responsibly — never stake more than you can afford to lose.

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