Betting odds guide: Everything to know about how to read odds and how odds work

Here's everything you need to know about the different types of betting odds and what all the numbers mean

Sports betting 101 begins with knowing how to read the odds and understanding how they work. Otherwise, an uninformed bettor may think that wagering money at -105 odds on the Super Bowl coin flip to come up tails provides value when, in the long run, it's a losing proposition.

With all due respect to Han Solo -- who upon being told that the possibility of successfully navigating an asteroid field was 3,720-1, replied, "Never tell me the odds" -- bettors should always know the odds when making wagers at their favorite sports betting apps.

What are odds?

The definition of the word odds is this: the probability a thing will or will not happen. For example, the probability that the Super Bowl coin flip will land on heads is 50% and tails is also 50%. So the true odds for each side of the coin would be +100. 

However, in sports betting, sportsbooks are also trying to make a profit. So the betting odds that sportsbooks post on an event will also factor in the sportsbook's commission, or "juice" or "vig." That means rather than receiving $100 for correctly betting $100 on the Super Bowl coin flip, a bettor may get only a $95.24 return if heads is -105 and tails is -105 instead of +100. The probability that an event will or will not happen based on the sportsbook's odds are implied odds. We'll talk more about the difference between sports betting odds and implied odds later.

What are the different types of betting odds?

Betting odds are most commonly expressed at sportsbooks in three different ways: American, fractional and decimal. Here is an overview of each:

American odds

These betting odds are the most common format among sportsbooks in the United States. Also known as "money line odds," American odds use either a plus or minus sign to represent potential payouts and implied probability.

When there are just two sides of a bet -- like when two football teams play -- the favorite generally is designated by the minus sign, and the underdog is designated by the plus sign. For example, in the 2025 College Football Playoff Championship Game between the Ohio State Buckeyes and Notre Dame Fighting Irish, the Buckeyes were listed at -400 to win the contest, while the Irish were +310. That means that Ohio State was the favorite, and anyone betting on the Buckeyes would have to wager $400 to win $100 (or $4 for every $1 for smaller bets). Meanwhile, Notre Dame was the underdog, and anyone betting on the Irish would win $310 on a $100 bet (or $3.10 for every $1 for smaller bets).

There are some instances in which both teams are designated by the minus sign. This occurs in games between teams deemed by the sportsbook as evenly matched. For example, in the 2025 Super Bowl odds between the Kansas City Chiefs and Philadelphia Eagles, FanDuel closed with the Chiefs at -118 and the Eagles at -108. Even though Philadelphia was the underdog in the game according to the sportsbook's NFL odds, an Eagles bettor needed to bet $108 to win $100. 

The American odds format is also used when there is more than one side, like on the winner of the Masters golf tournament or the Daytona 500. During the NCAA men's basketball tournament, for example, a sportsbook will post odds on each of the Final Four team's chances to win the national championship. Entering the 2024 Final Four, those odds were UConn Huskies (-200), Purdue Boilermakers (+200), Alabama Crimson Tide (+1600) and NC State Wolfpack (+1800). 

Fractional odds

Fractional odds are a different way to express the same sports betting odds, this time in a fraction format. It is most commonly used by British and Irish sportsbooks, but in the United States, horse racing uses the fractional odds format exclusively. Fractional odds can be identified by either a hyphen (-) or slash (/) between digits.

In simple terms, the number on the right of the fraction is what you'd need to bet in order to win the number on the left.

Using the 2024 Final Four example from above, the fractional odds were the following: UConn (1-2), Purdue (2-1), Alabama (16-1) and NC State (18-1). To calculate the potential payout, multiply the bet amount by the fraction. So a $10 bet on the Boilermakers to win the championship at 2-1 odds would have won $20 ($10 x 2/1) in addition to the initial $10 stake for a total potential payout of $30. However, the Huskies won the title, so people betting $10 on UConn at 1-2 odds received $5 in winnings ($10 x ½) plus their initial stake of $10 for a total payout of $15.

Fractional odds are the easiest to convert into probability percentages. A horse with 1-1 odds to win the Kentucky Derby, for example, has an implied probability of 50% to win. A horse with 2-1 odds has a 33% probability; 3-1 means a 25% chance, and so on. So the smaller the fraction (i.e. 1/2), the shorter the odds and the heavier the favorite. And the bigger the fraction (i.e. 100/1), the longer the odds and the bigger the underdog.

Decimal odds

This format is a third way to express the same odds, this time using decimals. This format is more common in continental Europe, Australia and Canada. Decimal odds represent the total return of the bet, including what was risked, for every dollar wagered.

Once again using the 2024 Final Four example from above, the decimal odds were the following: UConn (1.50), Purdue (3.00), Alabama (17.00) and NC State (19.00). So a person who bet $10 on NC State at 19.00 had a potential payout of $190 ($10 initial stake x 19.00 decimal odds). This payout includes the $10 initial stake.

Implied odds

All three of the betting formats—American, fractional and decimal—can and should be converted into implied odds by a bettor. Implied odds are a conversion of American, fractional or decimal odds into a percentage while also taking into account the sportsbook's edge.

Let's use the Super Bowl coin flip as an example. During Super Bowl LIX, some sportsbooks were offering heads at -105 and tails at -105. Converted into implied odds, -105 means this bet has a 51.22% chance of happening when, in fact, we all know that a coin flip is a 50% proposition. Anyone who bet one of these sides at -105 and wagered $100 received only $95.24 (plus their initial $100 stake) if the bet won. This is negative value that is a losing proposition in the long run.

Implied odds can help bettors place the sportbook's odds in a better perspective and help identify when a bet is a bad one.

Here is a table with some common sports betting odds expressed in American, fractional and decimal formats, as well as the corresponding implied odds for each.

Odds across different sports

For the four major North American sports—football, basketball, baseball and hockey—sports betting odds will look very similar.

Football

NFL and college football betting odds will be available for point spread, total and money line wagers for regular season games. Player props and team props will also be available. For bigger games for football betting, such as the Super Bowl and College Football Playoff Championship Game, sportsbooks will offer an endless array of betting options ranging from whether the coin toss will be heads or tails to which player will score the game's final touchdown.

Basketball

College basketball or NBA odds are very similar to those in football. Like in football, the most common basketball bets are point spread, money line and total. However, player props in basketball betting will obviously include points, rebounds and assists versus those in football (passing yards, rushing yards, receiving yards, etc.). 

Baseball

Baseball betting varies slightly from football and basketball. The main baseball bets are money line, run line, totals and prop bets. Money line, totals and prop bets in baseball work exactly the same as those in football and basketball. Prop bets will include hits, home runs and strikeouts, among other stats.

Since baseball teams score in runs and not points, the run line is the baseball betting equivalent to the point spread bet in football or basketball. However, the same principles apply. The run line bet will look something like this: Houston Astros -1.5 (-215) vs. Detroit Tigers +1.5 (+170). In this case, an Astros bettor would need Houston to win by two or more runs, while a Tigers backer would need the Tigers to either win or lose by one run.

Hockey

Once again, betting on hockey is very similar to football, basketball and baseball; only some terminology has changed. The main hockey bets are money line, puck line, totals and prop bets. Money line, totals and prop bets in hockey betting work exactly the same as those in football, basketball and baseball, except with different stats (goals, assists, shots, saves, etc.). 

The puck line bet is hockey's equivalent to the point spread bet in football/basketball and the run line bet in baseball. 

For hockey, sportsbooks also offer 60-minute lines, which give NHL odds based on three periods, not including overtime. While a bettor might find a "better" price on 60-minute lines than a standard money line, the bettor risks losing if the game goes into overtime.

Golf

The most common wagers in golf betting are tournament winner, top-five finish, top-10 finish, top-20 finish and first-round leader. A person could also wager on head-to-head and three-way matchups.

Horse racing

Horse racing is the only sport in North America in which the odds are almost exclusively in fractional format, not in American. The traditional bets are win, place (a wager on a horse to finish first or second) and show (a wager on a horse to finish first, second or third). There are also exotic wagers such as exacta (top two horses in the exact order), trifecta (top three horses in the exact order) and superfecta (top four horses in the exact order). And there are multi-race wagers in which bettors must string together the winner of two (known as the double), three (Pick 3), four (Pick 4), five (Pick 5) or six (Pick 6) races in a row.

However, unlike in other sports where a bettor gets the odds when the bet is placed, bettors in horse racing get the final odds when the starting gate opens.

Odds across different types of bets

The sportsbook odds will refer to something different depending on the type of bet.

Money line

As explained above, American odds are also known as money line odds. Money line bets can be offered when there are only two sides (Ohio State Buckeyes -400 vs. Notre Dame Fighting Irish +310) or when there are multiple betting options (Odds to win the Masters: Scottie Scheffler +370, Xander Schauffele +900, Rory McIlroy +1000, etc.). With money line, you are choosing the side that is the outright winner.  

Point spread

For point spread bets, which are most popular in football and basketball, one team will generally be favored by a certain number of points over the opponent. In this case, the betting odds will refer to the chances of the favorite winning by more than the point spread or the underdog losing by less than the point spread (or even winning outright). 

For example, let's say the Boston Celtics and Los Angeles Lakers play in a game, and the sportsbook's NBA odds have the Celtics at -5.5 (-112) and the Lakers at +5.5 (-108). If a person places a $100 bet on Boston to cover, that bettor needs the Celtics to win by six or more points in order to win $89.29. On the other hand, a Los Angeles backer who places $100 on the Lakers to cover needs them either to win outright or lose by five or fewer points in order to win $92.59.

Over/under (total)

Over/under or "total" bets work the same way as point-spread bets, but in this case the total number of points scored in the game is what is in question.

Let's imagine that the Texas Longhorns and Michigan Wolverines are scheduled to play a football game, and the sportsbook has posted the total on the game as the following: Over 54.5 (-112) and Under 54.5 (-108). If a person places a $100 bet on the Over, that bettor needs the teams to combine for 55 points or more in order to win $89.29. On the other hand, an Under backer who places $100 on the Under needs 53 or fewer points scored in order to win $92.59.

Player props

Just like for the total, a player prop is a bet that you can get Over or Under on and the odds are the price you pay to wager on your side of the bet. Let's say Shai Gilgeous-Alexander's points prop for an upcoming Oklahoma City Thunder game was 30.5, with Over 30.5 at -120 and Under 30.5 at +100. A $100 bettor who wants the Over would need Gilgeous-Alexander to score 31 or more points for a $183.33 return ($100 initial stake plus $83.33 profit if the bet hits). Conversely, a $100 bet on the Under would pay out $200 ($100 initial stake plus $100 profit) if he scores 30 or fewer points.

Futures

Futures betting is similar to money line in that the odds are the price of the outright winner. Futures were already released the 2026 Super Bowl, with the defending champion Philadelphia Eagles serving as the +650 favorites to repeat. A $100 wager on the Eagles at +650 would award the bettor with a total of $750 ($100 initial stake plus $650 profit) if they were to win it all again.

Parlay

A parlay is multiple bets that all have to hit in order for the parlay bet to win. Using two of the examples above, let's say a bettor wanted to build an NBA parlay featuring the Celtics -5.5 (-112) and Shai Gilgeous-Alexander Over 30.5 points (-120). By combining those two wagers, the parlay odds are now at +247. So a $100 bet on the parlay would have a potential payout of $347 ($100 initial stake and $247 profit). 

FAQ

Why do odds change?

Odds change when a sportsbook needs to adjust the price of a betting market. It can be due to injury news, weather information, sharp money coming in on a specific wager or other factors. Outside of horse racing, once you place a bet in any sport, you are locked into those odds even if they change afterwards. 

What is a "push" in sports betting?

A push is when the outcome lands exactly on the line, so the bet neither wins nor loses and the bettor receives the initial stake back. If the Philadelphia Eagles are -7 (-110) over the New York Giants and they win 27-20, a bettor who placed $100 on either Eagles -7 (-110) or Giants +7 (-110) would get their $100 returned. 

How do odds impact payout?

The odds impact your payout in two different ways. One is whether there is a plus sign or minus sign next to the odds. The other is the number next to the sign. Let's use two different cases, where one bet is -150 and the other is +300. With -150, the minus sign and the 150 tell bettors that they have to lay $150 to win $100 (or $75 to win $50 or any equivalent). With +300, the plus sign and the 300 mean that bettors would wager $100 to win $300 (or $20 to win $60 or any equivalent).

What does it mean when odds are negative?

When the odds of a bet are negative, it means that the sportsbook has given the implied probability of that outcome happening at greater than 50%. The betting favorite of any game will have a minus sign next to its money line and point spread since it is viewed that that team is more likely to win. It's important to remember how often you need to win your bets to break even when employing betting strategies for minus odds. For example, to break even betting -110 odds, a bettor needs to win 52.4% of his bets. 

What are Vegas Odds?

Vegas odds are lines that are featured from sportsbooks based in Las Vegas, including Caesars, BetMGM and Circa. People will sometimes use the phrase Vegas odds when referring to any odds; however, sportsbooks like FanDuel and DraftKings don't operate out in the state of Nevada.

Gene Menez

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