American Betting Odds Explained: How to read odds and understand what they mean

JUMP TO:

• What are American betting odds?
• How positive (+) and negative (–) odds work
• Examples of American odds in action
• How to calculate potential payouts
• Comparing American odds to decimal and fractional odds
• Tips for beginners learning odds

New players join the sports betting community every day, but they often don't take the time to fully understand how betting works.

One of the most important details to learn when beginning a sports wagering journey is odds.

Once you get to know odds, how to read them and what they mean, you will be in a much better place as a new bettor. This guide will help you learn the basics about American odds, familiarizing you with understanding value and making you comfortable enough to begin betting like a pro. 

What are American betting odds?

The most important thing to know in sports betting is how to understand the odds. Odds are pretty straightforward once you know the three basic terms:

• Moneyline
• Point spread
• Over/Under total

These are oddsmakers' projections for how a game will turn out, including the winner/loser, margin of victory, and final score combined points. Let's go into a little more detail before we proceed.

Moneyline

Moneylines are simple: it's a number — either positive or negative — assigned to each team in a set matchup. That number represents each team's odds to win. When bettors pick the straight-up winner of the game and put money on it, they're betting the moneyline.

The negative number (usually -105 or greater) typically represents the odds for the favorite, the team that the sportsbooks expect to win. The positive number (typically +100 or greater) represents the odds for the underdog, or the team less likely to win the game.

You will always win less of a payout on a winning bet with negative odds, and profit more on the payout of a winning bet with positive odds.

Moneylines allow oddsmakers to set and tweak odds for games based on each team's implied win probability. No sportsbook would ever give you 2-to-1 odds on an outright winner if that team was widely known to be the superior of the two in a matchup.

We often see lopsided or uneven matchups, even in the playoffs. Moneyline odds allow bettors to pick straight winners while also enabling sportsbooks to limit their liabilities attached to the overwhelming favorites.

How to read a moneyline

Reading moneylines is simple: Favorites have negative (-) odds, with the number indicating how much you would need to risk to make your potential profit $100. Underdogs have plus (+) odds, with the number indicating what you would win on a $100 bet.

Let's say you're betting on the NFL, with interest in backing the Eagles over the Giants in a regular season NFL game. If Philadelphia is listed as a -350 favorite, that means you would need to risk $350 to net a profit of $100 if Philly wins.

If you think the Giants will pull off a surprising upset, you could bet $100 on them at +350 and walk away with a $350 profit if New York indeed comes away with the win. 

Point Spread

Another way for oddsmakers to set odds for a game is through the spread. This is the process by which oddsmakers analyze both teams in a matchup, consider their strengths, weaknesses, and other factors, and assign a point spread that predicts how much the favorite will win by.

Betting the spread swaps out the moneyline odds for points. The favorite has points taken away from it, and the underdog receives those points.

If a team is projected to win, that favorite must win by more than the set amount — the spread — to cover. Similarly, teams projected to lose can only cover if that underdog either (a) wins or (b) loses by fewer points than the set spread.

Let's go back to the hypothetical Eagles-Giants game. Philly was listed as a -350 favorite, which roughly translates to an eight-point favorite against the spread (-8). That means you would have to bet on either the Eagles to win by more than eight or New York to lose by less than eight.

If the Eagles win by exactly eight, it's a push, and your initial wager would be refunded (for that reason, sportsbooks typically add a half-point to every spread amount, since teams can't win or lose by a half-point).

Point spreads always have a second set of odds alongside them, which indicate the cost of placing the bet (also known as the "vig" or the "juice"). Most point spreads have a vig of -110 — to win $100, you would need to risk $110. Vigs can be adjusted depending on betting action and can vary from book to book.

Over/Under total

People love betting the over/under, also known as the total. Betting the total is simple: the sportsbook lists a projected points total for a game, and you either bet on the two teams to finish with a combined score OVER or UNDER that total.

This is a very easy bet type to understand. If the total combined score winds up higher than the projected total, then the OVER wins. If the final score total is lower than the projected total, then the UNDER wins.

How positive (+) and negative (–) odds work

The plus (+) and minus (-) in sports betting refer to either the point spread or betting odds.

Spread

In spread betting, the "-" always refers to the favorite, and the "+" always refers to the underdog. The favorite is giving points to the underdog, who, in turn, is getting points.

To cover the spread, the favorite needs to win by more than that amount of points. The underdog doesn't need to win to cover — it can cover by simply losing by less than the spread.

Odds

Favorites usually have a "-" unless it's a pick'em (coin-flip) and both teams have negative odds. But in most cases, the favorite will have a "-" in front of its moneyline odds, while the underdog will have a "+" preceding the line.

Moneyline betting has nothing to do with the winning or losing margin but everything to do with wins and losses. Minus odds tell you how much you will need to risk to win $100. Plus odds tell you how much you will make on a $100 bet. 

Examples of American odds in action

Betting the moneyline

Say you're betting on a favorite, also known as the side the sportsbooks project to win a sporting event. In this case, we'll use the Philadelphia Eagles as an example, with the Kansas City Chiefs as the underdog (sorry, KC fans!).

Philadelphia Eagles -150
Kansas City Chiefs +120

If you bet on the Eagles (-150), you must wager $150 for the chance to win $100 in profit.

If you bet on the underdog Chiefs (+120), you will win $120 on a $100 wager.

Betting the spread

Going back to the same example of the Eagles vs. the Chiefs, let's say the Eagles are -2.5 favorites and the Chiefs are underdogs at +2.5. The odds attached to either side of the spread are -110, basically even money plus -10 vig for the books.

If you bet on the Eagles (-2.5), you need them to win by at least a field goal in order to cover.

If you bet on the Chiefs (+2.5), you need them to either (a) win or (b) lose by less than three points to cover.

The spread is referred to as the run line in MLB betting, the puck line in NHL betting, and handicap in soccer betting. It can also be used in prop bets as the difference in statistics between two players or teams.

Betting the Over/Under

The over/under is the most simply of the three major American odds. Say the over/under total is set at 48.5 points for the Eagles vs. Chiefs game.

If you bet the OVER, you need the total score to equal more than 48 points (49 or more).

If you bet the UNDER, you need the total score to equal fewer than or equal to 48 points. 

How to calculate potential payouts

Calculate payouts for negative odds (favorites) 

Formula:
Profit = (100 / [Odds]) * Stake 
Example: -150 odds on a $50 bet
Profit: (100 / 150) * 50 = $33.33

Total Payout: Your $33.33 profit plus your original $50 stake, for a total payout of $83.33. 

Calculate payouts for positive odds (underdogs)

Formula:
Profit = (Odds / 100) * Stake 
Example: +200 odds on a $50 bet
Profit: (200 / 100) * 50 = $100

Total Payout: Your $100 profit plus your original $50 stake, for a total payout of $150. 

Calculate a parlay payout

Parlays have become wildly popular over the years. In short, parlays allow bettors to combine multiple bets (legs) in one big bet for a larger potential payout. The odds of winning are longer because all bets in the parlay must win for the entire parlay to cash out even a penny. Thus, the potential reward is greater.

Bettors only need to combine two legs to make a parlay, but the most popular parlays tend to be in the range of 3-5 legs. The more wagers bettors add to parlays, the greater the risk for the bettor so therefore the bigger the potential payout. The odds get longer — the + number grows and grows — with every leg added.

Sportsbooks typically allow bettors to add between two and 12 games in a parlay. Some books will also allow you to incorporate player or game props, also known as over/under stat props.

Now that you know the definition of a parlay and how you can bet one, let's quickly break down how to calculate the odds for a parlay bet value.

Once you figure out the odds for each matchup, bet, or prop, just divide what the total payout would be by the bet amount.

Let’s imagine a $100 parlay bet on these teams:

• Dolphins (-150)
• Titans (+170)
• Texans (-120)

Miami: -150 to win 100 with a payout of $250 250/150 = 1.6666
Tennessee: +170 to win 170, with a payout of $270 270/100 = 2.7
Houston: -120 to win 100, with a payout of $220 220/120 = 1.8333E

Each of those three numbers we calculated is your multiplier.

Now, just multiply those numbers to get your parlay odds. 1.6666 x 2.7 x 1.8333 = 8.2495

That final number is 8.25, meaning your winnings would work out to be 7.25 for every dollar you bet on that particular parlay. Translation: your $100 bet just turned into a $725 win.

If you hate math or just don't want to go through the bother of calculating your parlay odds manually each time, have no fear. Most sportsbooks do the legwork for you, and you can also find a ton of independent parlay calculators all over the Internet.

Comparing American odds to fractional and decimal odds

While American odds use positive or negative numbers, fractional odds obviously use fractions and decimal odds obviously use decimals. 

Fractional odds (British or UK odds)

Generally used in the UK and Ireland, fractional odds display your potential profit relative to your stake. As you probably could have guessed, they are written as a fraction, such as 12/1 or 7/2.

How to calculate fractional odds

The fraction A/B means you will win 'A' units of profit for every 'B' units you put at stake.

Example: 7/2. For every $2 you bet, you will win $7 in profit. Your total return is $9 ($2 stake + $7 profit).

Fractional odds of 1/1 (aka "even money")

A bet of $10 wins you $10 in profit. This is equivalent to +100 in American odds or 2.0 in decimal odds. 

Decimal odds (European odds)

Commonly used in Europe, Canada, and Australia, decimal odds represent the total return for every $1 wagered, including your original stake.

Odds greater than 2.0 represent an underdog (a riskier bet with a higher potential payout).

Odds less than 2.0 represent a favorite (a safer bet with a smaller payout). 

How to calculate decimal odds 

To calculate decimal odds, multiply your stake by the decimal odd to calculate your total return.

Example: 2.50 odds. You stand to win $2.50 for every $1 wagered. A $10 bet will return $25 total ($10 stake + $15 profit).

U.S. odds conversion chart

Check out the conversion chart below to see how to easily translate odds from fractional and decimal to American. 

Advantage of using American odds, compared to decimal and fractional

Compared to U.K. and European odds, American odds typically give a more complete picture of your betting commitments, using the $100 betting foundation to clearly display how much profit a winning bet would actually earn the bettor. 

For instance, a winning +200 bet instantly reflects that you're getting $200 on top of your initial $100 stake.

This contrasts with the 3.0 decimal display not immediately conveying that your profit is only 2-to-1 on top of your stake.

While many fractional odds line up with easy double-ups and triple-ups, it's generally quicker to read +250 instead of calculating 5/2 once you've gained enough experience.

Tips for beginners learning betting odds

1. Price-compare to bet the best odds

Just like when you go shopping for something big, you want to place bets on the most economically priced odds. Get the most bang for your buck!

That means taking the time to join all the major sportsbooks in your state, then researching which book has the highest-possible payout on the bet you want to make.

Just like your investments and budget in everyday life, every little positive gain contributes to the big picture of your sports betting success.

The best way to accomplish this window-shopping is to use and odds screen at the betting data site of your choice.

2. Understand variables that shape odds

Consider the variables surrounding the sporting event so you can better understand the context of the game and therefore the reason the odds have been set a certain way.

Factors that can influence odds include injuries, weather, coaching changes, recent form or even the betting public. For instance, the Indiana Fever and Caitlin Clark might not be title favorites and MVP favorites, but if 75 percent of bets are on Indy and Caitlin, their odds will shorten quickly.

Understanding how variables play into oddsmaking can help you pinpoint value and land profits.

3. Read the betting reports

Most sportsbooks provide the betting numbers for sporting events, including the betting handle percentages and ticket percentages. The "handle" is the term for all the money bet on an event, and "tickets" refers to all bets made on that event.

Odds tend to reflect the market’s perception. If the majority of an events' bettors put their money on one outcome, the odds will likely shift to balance the betting.

Use this knowledge to your advantage by seeking out less popular bets that might offer better value. Considering the house usually wins, how often do you think the betting majority gets one over on the sportsbooks?

4. Research short-term and long-term stats/data

Get good at researching, and not just player stats. Look at previous matches between teams/players or check out past performances in similar conditions. History tends to repeat itself, and trends jump up all over the place in betting just like in sports in general. 

Get to know solid research sites like the Sports Reference umbrella and TeamRankings.com. Teach yourself how to interpret data so you can think like an oddsmaker or handicapper. Anticipate odds so you have a better grasp of value once odds go live for events.

5. Track your bets

Putting your wagers and win-loss statistics on paper -- or, say, online spreadsheets -- psychologically solidifies your monetary commitment, making things "real." 

You might also spot patterns in your strategy that could be frequently apply to picking your wagers or be improved toward achieving better results.

Always note which odds you locked in to see whether you're maximizing your return on investment.

Keeping this honest record will allow you to ...

6. Bet with your head, not your heart

Divorce your feelings from your betting method. You're trying to be an investor, not a fan.

Don't let losses get you down or force you into poor betting choices. Chasing losses is the equivalent of trying to dig yourself out of quicksand — it never ends well.

Stay consistent and trust your own process. Start small, with a bankroll strategy in mind, and never deviate from that until you multiple your bankroll exponentially.

Successful sports betting is a marathon, not a sprint, and you need to understand that you won't get rich quick unless you're really, really lucky. If you rely on savvy and preparedness over luck, you'll have a much better time as a sports bettor.