EV calculator
Expected value of a bet. Enter your model probability, the offered American odds, and your stake. We return the dollar EV, EV as a percent of stake, and the break-even win rate you need at the offered price.
Decimal 1.909
Expected value
$5.00
+5.00% of stake
Strong +EV
Your model projects >5% expected value over stake. Rare. Double-check your probability; real +5% EV bets are uncommon on sharp markets.
Break-even win probability
52.38%
You need to win at or above this rate just to break even at the offered price.
Profit if win
$90.91
Return on a winning stake at the entered price.
EV is only as good as your probability
The most common mistake with this tool is treating it as oracle output when the only real variable is your model probability. Garbage in, garbage out. If you overestimate your win rate by 2 percentage points, a +EV bet can flip to -EV and you will not notice.
Use this in combination with the no-vig calculator. If your no-vig fair price (derived from a sharp book) gives you a different implied probability than your model, trust the no-vig fair price more than your model unless you have hundreds of backtested samples proving otherwise.
No-vig calculator · Kelly calculator · CLV calculator · CLV essay
The most common mistake with this tool is treating it as oracle output when the only real variable is your model probability. Garbage in, garbage out. If you overestimate your win rate by 2 percentage points, a +EV bet can flip to -EV and you will not notice.
Use this in combination with the no-vig calculator. If your no-vig fair price (derived from a sharp book) gives you a different implied probability than your model, trust the no-vig fair price more than your model unless you have hundreds of backtested samples proving otherwise.
No-vig calculator · Kelly calculator · CLV calculator · CLV essay