Value Bet Calculator

A value bet exists only when your estimated probability is higher than the probability implied by the available price. This calculator converts decimal odds into an implied probability, compares that number with your own probability estimate and calculates expected value (EV) for the stake you enter.

For example, decimal odds of 2.20 imply about 45.45%. If your evidence-based estimate is 50%, the difference is a positive probability edge. The EV calculation then shows the average theoretical return or loss per stake if the same quality of estimate and price could be repeated many times.

How to use the result

• Use a probability estimate based on analysis rather than the size of the odds.
• Check the implied probability with the Implied Probability Calculator.
• Review bookmaker margin with the No-Vig Calculator before treating market prices as fair probabilities.
• A positive EV number is not a guarantee that one bet will win. Variance can dominate short samples.

Value, stake size and uncertainty

The most sensitive input is your estimated probability. Small forecasting errors can turn an apparent edge into a negative-value bet. If you use probability estimates for staking, compare the result with the Kelly Criterion Calculator and apply conservative limits rather than assuming the full theoretical stake is appropriate.