The three formats
American: Negative numbers (favorite) tell you what to risk to win $100. Positive numbers (underdog) tell you what $100 wins.
Decimal: Decimal numbers tell you what $1 returns including stake. 1.91 = $1.91 returned per $1 wagered.
Fractional: Profit-to-stake. 10/11 = risk $11 to win $10.
The only number that matters: implied probability
Convert any odds to implied probability: 1 ÷ decimal odds × 100.
-110 American = 1.91 decimal = 52.4% implied. You need to win 52.4% of bets at -110 to break even.
Why it matters
Forget the format. Convert to implied probability. Compare to your subjective probability of the outcome. Bet when you think your probability beats the implied probability.
Use the calculator
Type any odds in any format into our odds converter for instant 4-way conversion.
FAQ
Is sports betting hard to learn?
The mechanics are simple. The discipline is hard. Most beginners take a year of disciplined volume before becoming consistently +EV.
How much money do I need to start?
$50-$200 is enough to start. The number matters less than your discipline. 1% per bet means a $100 roll bets $1 per game.