American Odds
American odds (sometimes called “moneyline odds”) are the odds format used by virtually all US sportsbooks. They use positive and negative numbers to indicate favorites and underdogs.
How They Work
Negative odds (favorites): The number tells you how much you need to risk to win $100.
- -150 = risk $150 to win $100
- -300 = risk $300 to win $100
- -110 = risk $110 to win $100 (the standard line on most spreads and totals)
Positive odds (underdogs): The number tells you how much profit you make on a $100 bet.
- +150 = $100 bet wins $150
- +300 = $100 bet wins $300
- +100 = even money — risk $100 to win $100
The bigger the absolute value of the number, the more lopsided the matchup. -800 is a huge favorite. +800 is a huge underdog.
Why It Matters
American odds are the default format for any US bettor. Reading them fluently is the foundation for everything else — comparing prices, calculating implied probabilities, and making sense of every bet listed in any major US app. International bettors and exchanges typically use decimal odds instead.
Most edge-finding work — comparing lines across books, calculating arbitrage, evaluating expected value — uses implied probability under the hood. American odds are just the user-facing presentation. Once you can convert between American odds and implied probability quickly, the rest of betting analysis gets much easier.
For more on reading and comparing odds across formats, see How Betting Odds Work.