How American odds work
American odds are built around 100. A minus number is the favorite: it's how much you risk to win 100, so -150 means bet 150 to win 100. A plus number is the underdog: it's how much a 100 bet wins, so +150 means bet 100 to win 150. +100 is even money.
The most common odds
Decimal and fractional odds
Decimal odds (popular in Europe, Brazil and Australia) show the total return per 1 staked, stake included: 2.50 returns 2.50 for every 1. Fractional odds (popular in the UK and Ireland) show profit over stake: 3/2 wins 3 for every 2. +150, 2.50 and 3/2 are all the same price. Convert any of them in the odds converter.
What odds say about the chance of winning
Every price implies a probability: 1 divided by the decimal odds. -110 implies 52.4%, +150 implies 40%. Add up both sides of a market and you get more than 100%; the extra is the sportsbook's margin. The implied probability calculator strips it out to show fair odds.
Odds in a parlay
A parlay multiplies the decimal odds of every leg, so payouts climb fast and the chance of hitting falls just as fast. Try it in the parlay calculator, and see how often parlays really hit.