EV Calculator

What is +EV betting?

Expected value (EV) is the average profit or loss a bet would return if you could place it thousands of times. A bet is positive EV (+EV)when the odds you’re offered pay out more than the true chance of winning deserves. Do that consistently and the maths works in your favour over time — even though any single bet can still lose.

How the calculation works

Every set of decimal odds carries an implied probability — just 1 ÷ odds. Odds of 2.00 imply a 50% chance; 4.00 implies 25%. The bookmaker builds their margin into that number, so it’s always a little higher than the true chance.

• Fair probability (p)is the true chance, with the margin removed. You can enter it directly, or enter the fair (no-vig) odds and we’ll convert with p = 1 ÷ fair odds.
• EV per $1 = p × your odds − 1. Above zero is +EV; below zero is −EV.
• EV$ = stake × EV per $1.That’s your average edge on the bet in dollars.

Example: you’re offered 2.10 on a coin-flip whose fair price is 2.00 (a true 50% chance). EV per $1 = 0.50 × 2.10 − 1 = 0.05, so a $100 stake is worth about $5 on average — a 5% edge.

Where the fair price comes from

EV is only as good as your estimate of the true chance. Sharp bettors usually derive it by devigginga market — removing the bookmaker’s margin from a set of odds (our No-Vig Fair Odds tool does exactly this) — or by using the price at a low-margin, high-liquidity book as the reference.

Why the edges are small

Real +EV edges are usually a few percent, not headline numbers. They add up only across volume and discipline, and they assume you can actually get your bet down at the price shown before it moves. Books also limit accounts that consistently beat them. Treat the projections below as a ceiling, not a promise.

How Winora helps

Finding +EV by hand means devigging hundreds of markets a day. Winora does it automatically — scanning thousands of lines a second and posting the +EV bets, already devigged and sized, straight to your Discord.