What’s the Difference Between American, Decimal, & Fractional Odds?

In the world of odds and online sports betting, there are several different languages that are used to express the same idea.

In the United States, most bettors are used to American odds. American odds revolve around the number 100. 

For instance, a big moneyline favorite might be represented as -500. That’s a favorite that bettors must wager $500 on in order to win a $100 return. 

For underdogs, a +300 moneyline underdog will return a $300 profit on a successful $100 bet.

Fractional and decimal odds can offer the exact same favorites and underdogs, but those odds will be expressed differently.

In fractional odds, that -500 American favorite will instead be 1/5. In decimal odds, it will be 1.2.

Similarly, the +300 underdog is represented as 3/1 in fractional odds and 4.0 (or just 4) in decimal odds.

Big plus-rated numbers become more prevalent with parlays. You can use BetMGM’s parlay calculator as a helpful tool in this area.

What Countries Use Decimal Odds?

Decimal odds are primarily used in European countries. In fact, decimal odds are sometimes referred to as European odds.

This does not include the UK or Ireland, where fractional odds are common.

Decimal odds are also the favored form of numeric representation in Australia, New Zealand, and some parts of Canada.