How to read odds for betting

Sports betting is now legal in more than 30 states, and millions of Americans are placing bets for the first time. But before you put any money on the line, you need to understand how odds work. 

Odds will tell you how likely a sportsbook thinks an outcome is, and how much you stand to win. Once you can read them, everything else in sports betting starts to make sense.

American Odds (Moneyline)

Since you’re betting in the US, the format you’ll see most often is American odds, also called the moneyline. Every major sportsbook in the country, from DraftKings and FanDuel to BetMGM and Caesars, displays odds this way by default.

American odds always come with a plus or minus sign. That sign tells you immediately whether a team or player is the favorite or the underdog.

American odds always come with a plus or minus sign. That sign tells you immediately whether a team or player is the favorite or the underdog.

Minus (-) = Favorite. The number tells you how much you need to bet to win $100 in profit.

Plus (+) = Underdog. The number tells you how much profit you’d make on a $100 bet.

The +100 Midpoint

+100 is the natural midpoint of the system. At +100, a $100 bet wins exactly $100 in profit, a true even-money bet. Think of the entire scale as running from there in both directions where positive numbers climb as teams become bigger underdogs, negative numbers fall as teams become bigger favorites

How to Read a Negative Moneyline

When you see -300, the number tells you exactly how much you need to bet in order to win $100 in profit. At -300, you bet $300 to win $100. At -180, you bet $180 to win $100. The minus sign always means you’re betting more than you’ll win, which is the price of betting on a favorite.

To calculate the profit on any negative line, the formula is:

Profit = (100 / odds) x stake

So for a $100 bet at -300: (100 / 300) x 100 = $33.33 profit.

For a $100 bet at -180: (100 / 180) x 100 = $55.56 profit.

The higher the negative number, the bigger the favorite, and the less you win relative to what you risked. A team at -300 is a much stronger favorite than a team at -110, and your potential profit shrinks accordingly.

How to Read a Positive Moneyline

A positive number works the other way. At +300, a $100 bet wins you $300 in profit. The plus sign always means you stand to win more than you wagered, which reflects the added risk of betting on an underdog.

To calculate the profit on any positive line, the formula is:

Profit = (odds / 100) x stake

So for a $100 bet at +300: (300 / 100) x 100 = $300 profit of a $400 payout.

For a $100 bet at +175: (175 / 100) x 100 = $175 profit of a $275 payout.

The higher the positive number, the bigger the underdog, and the more you stand to win if they pull it off.

Other Formats You Might Run Into

If you use international sportsbooks, bet on soccer, or follow betting content from European sources, you’ll come across two other formats: decimal odds and fractional odds. Some US sportsbooks also let you switch between formats in your account settings.

Decimal Odds

Decimal odds show your total return per $1 wagered, including your original stake back. They’re popular in Europe, Canada, and Australia. To calculate your payout, multiply your stake by the decimal number.

Decimal odds	American equivalent	$100 bet total payout	$100 bet profit
1.50	-200	$150	$50
1.91	-110	$191	$91
2.00	+100	$200	$100
2.50	+150	$250	$150
4.00	+300	$400	$300

Fractional odds

Fractional odds are written as two numbers separated by a slash, like 5/2 or 7/1. They’re the traditional format used in the UK and Ireland, and you’ll see them most often on horse racing and golf. 

The left number is your profit; the right number is your stake. At 5/2, you win $5 for every $2 you bet, so a $100 bet returns $250 profit. At 7/1, a $100 bet returns $700 profit.

Odds implies the probability 

Every set of odds implies a probability. That’s the bookmaker’s built-in estimate of how likely an outcome is. Learning to convert odds to probability is the single most useful skill you can develop as a bettor, because it shifts your thinking from “who do I think will win” to “are these odds actually worth taking.”

Converting American odds to implied probability

For negative odds you divide 100 by (the absolute value of the odds + 100), then multiply by 100.

For positive odds you divide 100 by (the odds + 100), then multiply by 100.

Odds	$100 bet profit	Implied probability	Plain English
-300	$33	75.0%	Book thinks this team wins 3 out of 4
-200	$50	66.7%	Book thinks this team wins 2 out of 3
-110	$91	52.4%	Book thinks this is a slight lean
+100	$100	50.0%	Book calls it a coin flip
+150	$150	40.0%	Book thinks this team wins 2 out of 5
+300	$300	25.0%	Book thinks this team wins 1 out of 4
+600	$600	14.3%	Long shot

Key Terms Glossary when reading odds

These are the terms you’ll encounter on every sportsbook app and betting site in the US where some of them are self-explanatory once you know what to look for while others have specific meanings that differ from how they’re used in everyday language. 

Getting comfortable with this vocabulary won’t make you a better bettor overnight, but it will make sure you always know exactly what you’re agreeing to when you place a bet.

Term	What it means
Moneyline	A straight bet on who wins, no point spread involved
Point spread	A margin added to level the playing field between two teams
Over/under (total)	A bet on whether the combined score will be over or under a set number
Juice / vig	The sportsbook’s cut, typically built into the odds
Implied probability	The likelihood of an outcome as expressed by the odds
Favorite	The team or player expected to win; shown with a minus sign
Underdog	The team or player expected to lose; shown with a plus sign
Push	When the result lands exactly on the spread or total, and bets are refunded
Parlay	A single bet combining two or more picks, all of which must hit to win
Line movement	When odds shift between the time they open and when the game starts