Expected value calculator
How much is a bet worth on average? Enter the odds and how likely you think the player is to win.
- Expected profitper bet, on average
- Expected returnof the stake
- Your edgevs the odds
- Break-even chanceto not lose money
- Minimum fair oddsat your win chance
- Win paysprofit if it wins
The formula
Expected value (EV) is what a bet makes or loses on average if you could place it many times.
EV = (win chance × profit if it wins) − (lose chance × stake)
$100 at +150 with a 45% chance: (0.45 × $150) − (0.55 × $100) = +$12.50
A positive EV means the odds pay more than the risk deserves, at your win chance. The catch is that the answer is only as good as that win chance. If it's too optimistic, the EV is too.
Where to get a win chance
Every match on the daily matches page has the Tennis Gauge model's win chance, and each match preview links here with its numbers filled in. You can see how those picks have actually done on the track record page.
Common questions
What is a +EV bet?
A positive expected value bet is one where the odds pay more than the risk deserves, given your estimate of the win chance. Placed many times, it would make money on average.
How do you calculate expected value in betting?
Multiply the win chance by the profit if it wins, then subtract the lose chance times the stake. $100 at +150 with a 45% chance: 0.45 x $150 - 0.55 x $100 = +$12.50.
What win percentage do you need to break even?
The odds' implied probability. At -110 you need to win 52.4% of the time; at +150 you need 40%.
More tools
- Odds converter: American, decimal, fractional and implied probability, converted as you type
- No-vig calculator: remove the sportsbook's margin to see fair odds and true probability
- Today's tennis matches: model win chances to plug into these calculators
Calculators are for information only. Bet responsibly.