Expected value calculator

Expected value is what a stake returns on average at a price if the chance of winning is the one you put in. Enter a price and your estimate of the chance, and the calculator does the arithmetic. It cannot tell you whether your estimate is right.

Worked example At +150 (decimal 2.50), with your estimate of 45%, the expected value is 45% × 2.50 − 1 = +12.5% of the stake, +12.50 on a stake of 100. The price breaks even at 40%.

Expected value (share of stake): +12.50%
Expected profit on the stake: +12.50
Break-even probability: 40.00%
Your estimate minus break-even: +5.00 pts
Fair odds at your estimate: +122 · 2.22

How it works

Expected value per unit staked = your chance × decimal odds − 1. Above zero the price pays more than your estimate says it is worth; below zero, less.

Break-even probability = 1 ÷ decimal odds: the chance at which the expected value is exactly zero. It is the price’s implied probability, margin included.

The estimate is the uncertain part. The market’s fair chance (see the no-vig calculator) or a model’s projection is a place to start, never a promise.

Arithmetic on the numbers you enter, for research. It is not betting advice: Keel Stats sells no picks and links to no sportsbook. Responsible gaming