Betting odds tell us everything about a wager. The amount of money you can win, the likelihood of a certain outcome, and the amount of risk you're taking are all displayed by betting odds aka the price.
There are three primary forms for odds:
- American Odds - Used in the USA
- Decimal Odds - Used in Europe and the Rest of the World
- Fractional Odds - Used in the UK
Reading odds correctly is crucial whether you're betting on an NBA or NFL game, a Premier League matchup or any other sports betting wagers you wish to place and even for sportsbook promos.
Betting Odds Explained – US/American Odds

In the United States, sportsbooks betting odds are typically shown in the American format. These odds are centered around a $100 base value and appear with either a minus (-) or plus (+) sign.
- If your bet wins, you get the profits and your stake back so this must be factored into any potential payouts from a wager. Your stake is always returned to you on a winning bet.
Understanding this system is the foundation of smart sports betting. It not only tells you how much you could win but also hints at the bookmaker’s view of a team’s chances.
Favourites (Minus Sign)
Negative odds ( with a - sign) means the team is the favorite. The number shows how much you must bet to win $100.
Underdogs (Plus Sign)
Positive odds (with a + sign) means the team is the underdog. The number in front of the sign denotes how much you would win if you were to bet $100
American Odds Made Easy
American or US odds, as they’re commonly known, are the most popular type of pricing in the United States on both sports betting apps and sites. While they might seem tricky at first, they’re easy to master once you know what to look for. Here's how to identify the favorite and underdog in a flash:
- Underdogs: Odds that indicate how much you may win on a $100 wager are shown by a plus sign.
- Favorites: The odds of winning $100 are indicated by the betting odds with a - sign.
Take note that every successful bet returns the profit plus the original stake.
For Underdogs (+):
- Winnings = (Stake × Odds) / 100
- Example: A $100 bet @ +110
- Math: (100 × 110) / 100 = $110
- So: $110 Winnings + $100 Stake = $210 Payout
For Favorites (−):
- Winnings = (Stake / Odds) × 100
- Example: A $100 bet @ -150
- Math: (100 / 150) × 100 = $50
- So: $50 Winnings + $100 Stake = $150 Payout
How to Read Betting Odds (US) – NBA Betting Example
Using a real-world example from a popular US sport, let's examine how American odds operate. Let's say the NBA season begins with the Golden State Warriors against the Philadelphia 76ers. The odds might be as follows: If any of the terms below confuse anyone, fear not our sports betting glossary has all the answers.
- Philadelphia 76ers @ +155
- Golden State Warriors @ -180
Here’s what that means:
For the 76ers (Underdogs) @ +155:
- Winnings = (Stake × Odds) / 100
- Example: A $100 bet @ +155
- Math: (100 × 155) / 100 = $155
- So: $155 Winnings + $100 Stake = $255 Payout
For Warriors (Favorites) @ -180:
- Winnings = (Stake / Odds) × 100
- Example: A $100 bet @ -180
- Math: (100 / 180) × 100 = $20
- So: $20 Winnings + $100 Stake = $120 Payout
How US Betting Odds Work – Superbowl Betting Example
Now that we understand the fundamentals of US betting, let's apply them to a real-world scenario. Consider the Kansas City Chiefs vs. Philadelphia Eagles Super Bowl game from the previous year, which saw Philadelphia win handily: Eagles 40, Chiefs 22. Let's examine the moneyline odds, which are utilized while placing bets on the game's clear winner:
- Kansas City Chiefs @ -120
- Philadelphia Eagles @ +200
We can rapidly determine the possible payments for both favorites and underdogs using these odds.
Favorite: Kansas City Win @ -120
- Stake: $120
- Profit: $100
- Total Winnings: $220 (Stake + Profit)
Underdog: Philadelphia Win @ +200
- Stake: $100
- Profit: $200
- Total Payout: $300 (Stake + Profit)
Naturally, we know that most people are not betting $100 on every event or play. Let’s look at a lower stake—say, $5—to see how American odds work at smaller levels.
US Gambling Odds with a $5 Stake
Favorite: Kansas City @ -120
- Math: ($5 ÷ 120) × 100 = $4.17 profit
- Total Payout: $4.17 + $5 = $9.17
Underdog: Philadelphia @ +200
- Math: ($5 × 200) ÷ 100 = $10 profit
- Total Payout: $10 + $5 = $15
So, whether you’re betting big or small, understanding how to read sports betting odds helps you measure potential returns. With American odds, the key rules to remember are
- Favorites (-): How much do you need to stake to win $100
- Underdogs (+): How much you’ll win if you bet $100
Gambling Odds - Soccer Preview
Major League Soccer has returned. Every one of the league's 30 teams is starting from scratch, all bidding to topple Lionel Messi and Inter Miami. It’s the dawn of a new season where every club will face its own set of trials and tribulations on the road to the playoffs.
MLS Opening Day
We start on Saturday with St Louis City taking on Charlotte. Charlotte FC secured a playoff berth last season, finishing 4th in the East. and have bolstered their ranks with Wilfred Zaha. A St Louis side that finished 13th in the West shouldn’t challenge too much.
Meanwhile, a true heavyweight clash features LAFC and Son Heung-min taking on Messi’s Inter Miami. It’s a classic East-meets-West showdown that will have the stars out in full force to witness some of the world's most iconic players. LAFC will be hunting for some redemption after being dominated by the Miami squad during their last encounter.
Transfer Tracker
Minnesota United is making headlines after snagging Colombian sensation James Rodriguez. The former Real Madrid and Everton star is the centerpiece of a Minnesota team looking to improve on their top-four finish from last year. His first test comes against an Austin FC side that will have to be at their absolute best to contain him.
San Jose is also looking like a playoff contender after signing Timo Werner from the European ranks. The German forward has played for some of the biggest clubs in the world, and his arrival in San Jose signals a new era for the Earthquakes' front line.
In another major signing, André Gomes joined the Columbus Crew. The former Barcelona and Everton midfielder is a high-level addition to the Crew’s roster as they prepare to take on the Portland Timbers—a team that is always a difficult opponent for anyone in the league.
Betting Odds Explained Decimal – European Odds

Decimal odds are the easiest format for new bettors to understand. Popular in Europe, Canada, and Australia, these odds show you exactly how much your total payout will be, including both your profit and your original stake.
Here’s how it works:
- You multiply your stake by the decimal number to get your total return.
- There’s no need to break out formulas or ratios—just a quick calculation and you’re done.
- So if the odds are 3.00, a $10 bet returns $30 total (that’s $20 profit + $10 stake).
Favorites and Underdogs with Decimal Odds
Decimal prices also make it easy to spot favorites and underdogs:
- Numbers under two: 1.25, 1.5, 1.66 = Favorites
- Numbers over two: 2.35, 3.50, 5.90 = Underdogs
The lower the decimal, the more likely the sportsbook thinks that team is going to win, and the less you’ll earn for betting on them. Let’s see how this looks in a live sports setting.
How do betting odds work (Decimals) – NBA Betting Example
Let’s shift over to the NBA for this one. Consider a major matchup between the Boston Celtics and the New York Knicks. The odds might be as follows:
- New York Knicks @ 1.57
- LA Lakers @ 1.57
Favorite: New York Knicks @ 1.57
- Stake: $20
- Total payout: $20 × 1.57 = $31.4
- Profit: $11.40
Underdog: LA Lakers @ 2.00
- Stake: $20
- Total payout: $20 × 2.00 = $40.00
- Profit: $20.00
Let’s break this down again with a smaller, $5 wager to show the simplicity of decimal odds.
Boston Celtics @ 1.57
- $5 × 1.57 = $7.85 total (profit: $2.85)
New York Knicks @ 2.00
- $5 × 2.00 = $10 total (profit: $5)
Decimal odds are often favored by beginners because they require just one quick multiplication. Simply glance at the number to determine which team is the favorite without using plus or minus signs.
Betting Odds Explained Fractional – UK Odds

Fractional odds—also known as UK odds—are commonly used in the United Kingdom and by some US-facing sportsbooks. They’re displayed as a fraction, such as 5/1 or 1/2, and show bettors how much they’ll win relative to their stake.
- The first number (the numerator) tells you how much profit you’ll make.
- The second number (the denominator) is the amount you need to stake to earn that profit.
- So, odds of 10/1 mean that for every $1 you stake, you’ll get $10 profit plus your original $1 back—$11 total.
Spotting Favorites and Underdogs
Fractional odds also make it easy to see the favorite and underdog:
- If the first number is bigger than the second (e.g. 5/1), that team is the underdog.
- If the second number is bigger than the first (e.g. 1/3), that team is the favorite.
These odds are often used in horse racing and soccer, but you may also find them offered on big US games. Let’s look at how they work using the same Super Bowl example from earlier.
How to Read Betting Odds (Fractional) – NFL Betting Example
Let’s go back to the Buffalo Bills vs Baltimore Ravens, but now view it through the lens of fractional odds. Instead of American odds, the same lines might be offered like this:
- Buffalo Bills @ 5/6
- Baltimore Ravens @ 2/1
Here’s how those would play out:
Favorite: Buffalo Bills @ 5/6
- For every $6 staked, you’d win $5 in profit
- Stake: $12
- Winnings: $10 profit + $12 stake = $22 returned
Underdog: Baltimore Ravens @ 2/1
- For every $1 staked, you’d win $2 in profit
- Stake: $10
- Winnings: $20 profit + $10 stake = $30 returned
Let’s take another example from the NBA this time—say, the Boston Celtics vs. Denver Nuggets- betting $20 this time:
- Celtics @ 4/7 (favorites)
- Nuggets @ 5/2 (underdogs)
Favorite: Celtics @ 4/6
- For every $6 you bet, you get $4 in profit.
- So if you bet $20, that will be 20 × 4/6 = $13.33 profit
- Total payout: $13.33 Winnings + $20 Stake = $33.33 Payout
Underdog: Nuggets @ 5/2
- For every $2, you get $5 in profit.
- So for a $20 bet, you’d earn $50 profit
- Total payout: $50 Winnings + $5 stake = $55 Payout
With fractional odds, it’s all about how much you need to bet to earn back a return. But if the fractions are confusing, many US sportsbooks allow you to switch odds formats in your account settings.
Additionally, a lot of online sportsbooks allow you to change your settings between American, decimal, and fractional odds.
After dissecting each of the main odds formats, let's examine how odds represent chance in more detail and how knowing this may help you identify value in your wagers.
Betting Odds Probability Explained
We can go a bit farther now that you understand how to read American, fractional, and decimal betting odds. These odds are typically used to calculate the likelihood that a wager will win.
Probability in sports betting is the chance that an event will occur. This possibility is reflected in the odds used by sportsbooks, where shorter odds indicate a higher chance of an event playing out and longer odds indicate less likelihood of an occurrence. Understanding how to determine implied probability from odds is beneficial for bettors since it:
- Can suggest whether a bet is worth the risk
- Spot when sportsbooks may undervalue or overvalue a side
- Make more informed picks when choosing between close matches. Odds format uses its simple formula to work out the implied probability. Don’t worry—it’s easier than it sounds.
Why Implied Odds Matters for Bettors
By converting odds into probability, you can:
- Compare your odds with what the sportsbook believes
- Identify value bets where you think the chance of success is higher than the implied odds
- Avoid bets that look flashy but are priced against you
This is how sharper bettors spot good lines and make smart wagers over the long run—not just by knowing teams, but by knowing the numbers.
US Gambling Odds Probability Explained
With American odds, the math depends on whether the wager is on a favorite (-) or an underdog (+).
For Favorites (-):
- Favorites Formula: Probability (%) = Odds / (Odds + 100) × 100
- Example: @ -300
- Math: 300 / (300 + 100) × 100 = 75%
For Underdogs (+):
- Underdogs Formula: Probability (%) = 100 / (Odds + 100) × 100
- Example: @ +400:
- Math: 100 / (400 + 100) × 100 = 20%
So in the examples above:
- A -300 favorite has a 75% implied chance to win
- A +400 underdog has a 20% implied chance to win
Fractional Betting Odds Probability Explained
For Fractional odds, the formula is also quite easy—just flip the fraction into numbers and plug them in. There is only one piece of math for it handily.
Fractional Odds Formula:
- Probability (%) = Denominator / (Denominator + Numerator) × 100
For Favorites (Bottom Heavy):
- Example: 4/5
- Math: 5 / (5 + 4) × 100 = 55.56%
For Underdogs (Top Heavy):
- Example: 6/1
- Math: 1 / (1 + 6) × 100 = 14.29%
So in this case:
- 4/5 odds suggest a 55.56% chance
- 6/1 odds implies a 14.29% chance
Decimal Gambling Odds Probability Explained
Decimal odds are the most straightforward when calculating probability, with just a single and supremely simple bit of math.
Formula:
- Probability (%) = 1 / Decimal Odds × 100
For Favorites (Under 2):
- Example: 1.40
- Math: 1 / 1.40 × 100 = 71.43%
For Underdogs (Over 2):
- Example: 2.75
- Math: 1 / 2.75 × 100 = 36.36%
So with decimal odds:
- 1.40 odds imply a 71.43% chance of winning
- 2.75 odds imply just a 36.36% chance
Betting Odds Explained – Common Bet Types
Since you have a firm grasp on how betting odds operate, next we’ll look at the kinds of bets you will encounter. With US sportsbooks, there are various events to place bets on, including scores, margins, statistics, and even player performance, in addition to winners and losers.
Here are the most common types of bets that new and experienced bettors alike encounter.
Moneyline Odds

The moneyline is the most basic form of sports betting—just pick who will win. There is no point spread or margin involved, and the odds are displayed in the American style (such as -150 or +200).
For instance, you would have to wager $120 to win $100 if the New York Knicks were favored by -120 to defeat the Miami Heat. If the Heat win, a $100 wager would provide a $110 profit if they are +110.
Pros: Simple and direct
Cons: Favorites offer lower returns
Totals (Over/Under)

When you place an Over/Under wager, you're forecasting the game's overall number of points rather than choosing a team.
Example:
- The Clippers vs. Blazers game has a total set at O/U 224.5 points.
- If you bet the over, it means both teams must score 225 points or more for your bet to be successful.
- And if you bet the under, the combined score of both teams needs to be 224 points or less.
Pros: Great when you have a read on game tempo or defense.
Cons: A close finish to the line can be a nail-biter
Spread (Point Spread)

Spread betting is about the margin of victory. The underdog was awarded extra points to even out the playing field. This is denoted with a number, as shown in the example below
Example:
- The Atlanta Falcons -4.5 vs the Los Angeles Rams
- If you bet on the Falcons, they need to win by 5 or more points.
- If you bet on the Rams, they need to lose by 4 or less (or win outright) for your bet to be successful.
Pros: More balanced odds between teams
Cons: Winning the game isn’t always enough to win the bet
- What does spread mean in betting? Our expert breaks it down here
Parlays

A parlay is when multiple bets are combined into one bet slip. All of the bets have to be successful for the parlay to pay out.
Example: You place a parlay on:
- Dallas Cowboys to win
- Saquon Barkley Anytime TD
- Jalen Hurts Over 200 Passing Yards
If just one leg fails, the entire bet loses. But if all hit, your payout is much higher than betting them separately.
Pros: Big payouts on small stakes
Cons: High risk—all picks must win
Props

Prop bets are bets within the game. It doesn’t depend on the final score of the game, but rather on little things like how many goals or points a player will score, corners taken by a team, and so on.
Examples:
- How many passing yards for Aaron Rogers?
- How man corners will PSG get in the second half?
- Will the first goal in a Chelsea game be scored in the first 32 minutes?
Highlights: Entertaining, targeted, and ideal for fans who are player-focused
Cons: High variance in expected outcomes.
Anyone who wants to wager well must comprehend these popular bet types. Knowing what you're betting on and why gives you the advantage, whether you're sweating a multi-leg parlay or supporting a favorite on the moneyline.
