How Do Sports Betting Odds Work: #1 Guide to Understand The Odds

Have you ever wondered what the odds are on a sports game? What does it mean to say that the odds are whatever they are? Why do they place odds on the games and events?

Many questions looking to be answered… Which is precisely what our experts did! One thing is undeniable: new gamblers should know about it before placing a sports bet. So, let’s find out how do sports betting odds work!

Key Takeaways

  • Learn how to calculate your winning chances.
  • You’ll know which and when type of odd to peak to boost your sport bets.

My Personal Experience with Sports Betting Odds

Growing up, I never grasped what sports betting odds meant. The Carolina Panthers were +3.5, Cam Newton was -350 for the first pick in the 2011 NFL Draft, and I was clueless about these numbers. I simply didn’t understand sports gambling at all.

Years later, I’ve mastered these terms, and it has transformed my involvement in sports. Now, I can navigate the sports betting industry with ease, which allows me to make money and deepens my engagement with the sports I love.

Additionally, understanding the odds has enhanced my grasp of the games themselves and made me a savvier bettor and a more informed fan. And the good news? You can do it, too! With this article and our betting 101 section, you’ll be able to master sports betting in no time!

What Are Sports Betting Odds? Calculate the Chances To Win!

Sports betting odds indicate the likelihood of an outcome, with lower or negative numbers suggesting a higher probability of occurrence. This is how experts predict outcomes in the unpredictable realm of sports.

DraftKings, a recognized and reliable sportsbook, explains that odds are typically presented in a “number to number” format, where the first number indicates the less favorable outcome.

For example: 3 to 1 odds mean there is a three times greater chance of losing than winning.

Betting odds are a tool that reveals an oddsmaker’s opinion (or stance) on a particular game, event, or proposition. They also reflect how much money bettors must risk winning a specific amount.

The odds are primarily tied to two things: Probability and money. 

Matt De Saro & Brian Pempus of Forbes, Betting Experts

Despite the inherent unpredictability of sports, setting odds is a way to bring some predictability and control, using extensive information to reflect the most likely reality before an event.

Types of Betting Odds Explained: Decimal, American, and Fractional Odds

To beat the odds in sports betting, you need to know exactly what types of odds you are dealing with. There are 3 types of betting odds you should be aware of.

Decimal Odds

Decimal odds represent the total payout you receive for every $1 wagered, including your original bet. More common outside the United States, but still relevant for U.S. bettors to understand.

Decimal odds provide a straightforward way to see total potential winnings relative to the stake.

Decimal odds are shown as one number, which is the amount a winning bet would collect on a $1 bet. If the odds are listed as 6, a winning bet would receive a $5 profit and the original $1 bet.

Anything between 1 and 2 is a favorite bet, and 2 is an even money bet.

Betting expert Dan Santaromita of The Athletic

American Odds

American odds are based on a $100 betting unit. They indicate how much you would win for every $100 wagered. These odds can be more challenging to understand due to their $100 baseline.

American odds help you calculate potential winnings, aiding in assessing whether the bet is worth the risk.

Dan Santaromita, here, said:

If the odds are -110, a common number for a bet involving a spread, you would need to bet $110 to win $100. If your odds are -200, you would need to bet $200 to win $100.

Of course, bets don’t have to be that size, but that proportion will scale up or down. A $10 bet with -200 odds would give you $5 plus your original $10 bet back.

Fractional Odds

Fractional odds represent winnings as a fraction, where the numerator (top number) is the amount you could win and the denominator (bottom number) is the amount you bet.

Favorites vs. Underdogs: Favorites have a denominator greater than the numerator (e.g., 1-2, 2-5), indicating lower winnings for higher stakes. Underdogs have a numerator greater than the denominator (e.g., 4-1, 9-2), offering higher winnings for lower stakes.

Though not always used, fractional odds are effective for quickly understanding potential returns on bets.

For fractional odds, he said:

In America, fractional odds are most commonly used in futures betting where almost all the odds have a denominator of 1, making them easier to understand.

How to Read and Calculate Betting Odds: Work Out What They Mean

Odds to ReadExplanation
+150 MoneylineBet $100 to win $150 (plus the original bet back) if it hits
-2.5Team is favored to win by 3 or more
+200Team is underdogs by 200, their opponent is likely minus something in comparison
Over/Under 23.5Player is predicted to score 23.5, you have to choose if he will hit more or less
6/1The chances it will happen. The lower the top number, including if it’s lower than the bottom number, the higher the chance of it happening. 

→ You can insert your own numbers into these templates and come out with the same examples. Swap the 150 in the first example for a 100 bet, then it means you’d have to bet $100 to get the $100 back and another $100 on top.

The – and + on a sports betting line indicates both your potential payout and whether you’re betting on the favorite or the underdog in moneyline odds. Negative numbers signify the favorite on a moneyline bet.

The negative number indicates how much you’d need to bet to win $100. If there’s a positive number, you’re looking at the underdog, and the number refers to the amount of money you’ll win if you bet $100.

Sports betting expert, Patrick Cwiklinski for Sports Betting Dime

Understanding Positive and Negative Odds: Both Types of Odds, Explained

Understanding positive and negative odds is not that complicated. My fellow TrustnBet specialists, and I, have deciphered these types of odds for you:

  • Negative Odds (-): Indicate the favorite.
  • Positive Odds (+): Indicate the underdog.

Example: In the Super Bowl,

  • The San Francisco 49ers are favored with odds of -130.
  • The Kansas City Chiefs are the underdog with odds of +108.

    Only two teams remain, creating a scenario where one has negative odds (favorite) and the other positive odds (underdog).

Early in the NFL season, futures bets on awards are typically positive for all candidates due to the high unpredictability over the 17-week season.

For instance: Lamar Jackson might start the season at +250, but as the season progresses, odds fluctuate based on performance and other variables.

This example underscores how odds reflect the likelihood of events, with negative odds assigned to more probable outcomes (favorites) and positive odds to less probable outcomes (underdogs).

Special Focus: Vegas Odds and Their Influence

Understanding Vegas odds is directly linked to knowing who’s setting the sports betting odds.

Vegas odds refer to the betting odds set by sportsbooks, commonly in Las Vegas, the betting capital of America. These odds are integral to American sports betting, often including point spreads and total points predictions (over/under bets).

Example: Las Vegas sportsbooks might set the Oklahoma City Thunder as -4.5 favorites over the Philadelphia 76ers or predict Nikola Jokic as +175 to win NBA MVP.

Las Vegas has a pivotal role in setting and changing these odds, affecting all American markets. Changes can occur due to various factors, including live betting and cash-out options. Las Vegas’s influence dates back to when it was one of the few places in the U.S. legally allowing gambling.

Vegas odds are not just specific figures, but a broad term that encapsulates the odds-making process in American sports betting, dominated by Las Vegas bookmakers.

Practical Examples and Betting Strategies To Read Sports Betting Odds

The spread is a prevalent form of odds that predicts the victory margin in a game.

For instance, in the 2024 Super Bowl, the opening odds set the Chiefs against the 49ers with a 1.5 point spread.

In my experience, larger spreads suggest better betting odds. A team favored by -9.5, for instance, is less likely to cover the spread against a competent NFL team capable of keeping the game close.


Regarding the Chiefs +1.5 in the Super Bowl, I would advise caution. Given their underdog status, the slim margin makes it a risky bet. Instead, betting on the 49ers to cover makes more sense, as one-point games are rare in the NFL, and the 49ers are likely to win by more than a field goal.

The spread is crucial for gauging how tightly contested a game might be, guiding strategic betting decisions.

Apply this Knowledge of Odds in Your Future bets

Mastering sports betting odds is crucial for successful betting. Different odds signal various outcomes, and knowing how to interpret them is essential to pick the best odds in sports betting.

Education is your best weapon in navigating sportsbooks effectively. We’re here to help you understand and convert odds, enhancing your gambling strategy.

Refine your skills and dive deeper into this topic on our website—your next win could just be a bet away!

Frequently Asked Questions

What do odds of -200 mean?

-200 odds means that a team is favored to win, and the bet would require $100 to win $200 back. 

How do sports betting odds work NBA?

Sports betting odds in the NBA are set by oddsmakers in an attempt to determine the outcome and the spread, score, and more. They represent the likelihood of an outcome in the basketball world happening. 

What do the + and – mean in sports betting?

The + in sports betting means they’re not the favorite, while the – symbol means they are. 

What does minus 1.5 mean in betting?

Minus 1.5 means that the team, whichever is the minus, is expected to win by two points. The decimal is set in between points to force bettors to choose whether it will be more or less. 

Is it better to be plus or minus in odds?

It is better to be minus in odds, since that means it’s a better chance of happening.