American Odds Explained

I’ve been betting for many years now and it’s very ignorant of me but I’ve never bothered to learn how American odds work. As soon as I see the likes of -100 and +150 alongside betting selections on a website I immediately try to find somewhere I can convert the odds to decimals and if I can’t, I usually leave.

Keen to learn more about the great US sports like American Football, Baseball and Ice Hockey though, I thought it was a bout time I found out how American odds work. How can I call myself a betting expert if I don’t know that. Sports betting might well become legal in several US states soon, so who knows, maybe we can interest a few Yanks in our site and teach them about real football.

Anyway, it turns out that they are not as complicated as they look. American odds start with either a plus (+) or a minus (-). Wherever you see a minus figure that is how much you need to stake to win $100 and wherever you see a positive figure that is how much you’d win if you staked $100.

US odds

So, in the example above you’d need to stake $132 on Chelsea to win $100. If you stake $100 on Man United, you’d win $418 if they won and $100 on the draw would see you return a profit of $287, if it ended up a stalemate.


Negative American odds profit calculation:

Profit = (100/Odds) x stake


Positive American odds profit calculation:

Profit = Odds x (stake/100)


Here is an American odds to decimal conversion table so you can get an idea of the two formats like for like.

American odds Decimal odds American odds Decimal odds
-101 1.990 +100 2.000
-105 1.952 +105 2.050
-110 1.909 +110 2.100
-120 1.833 +120 2.200
-130 1.769 +130 2.300
-140 1.714 +140 2.400
-150 1.667 +150 2.500


We’ve also got a very handy betting odds conversion infographic on our site that shows all the key fraction version off the odds alongside the decimal odds and the percentage likelihood of them winning.

It’s sometimes difficult to know if you are getting better odds on betfair exchange after commission has been factored in and so I’ve knocked up an after commission spreadsheet that shows all the odds after the default 5% commission. You can change the commission amount in the top right corner.