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Calculators to read odds, size a stake and measure variance. In your browser, no account, on your own assumptions.

Implied probability and margin calculator

Convert odds into probabilities, measure the bookmaker’s margin and find the fair price of each outcome.

Size your stake from your odds, your probability estimate and your bankroll, with a cautious Kelly fraction.

Simulate hundreds of betting runs to see what luck can do to your bankroll: drawdown, risk of ruin, range of results.