David spent 25 years as both a writer and editor within the betting/casino industries - including at The Guardian, Racing Post, 888Casino and Sky Sports Racing - prior to joining BBI. He has a diploma in sub-editing and law, is the author of four books, and remains a successful sports tipster.
All posts by David MyersPlus and minus are common terms used in sports betting that refer to the American odds format. This format is used primarily in the United States and Canada, and it is based on the concept of betting $100. The plus and minus signs indicate whether a team or player is favored or unfavored to win a particular game or match.
In American odds, the plus sign represents the underdog, and the minus sign is reserved for the favorite. Take a game between the New York Yankees and the Boston Red Sox as a simple example. Should the Yankees have a plus sign next to their odds, that means they are the underdogs, and a bet on them would pay out more money if they win. The Red Sox, by contrast, might show a minus sign next to their odds. That makes them the favorites, so a bet on them would pay out less money if they win.
Plus and minus are also commonly used in over/under bets and spreads. In a total bet, the sportsbook will set a total number of points, runs, or goals that both teams are expected to score. Bettors can then bet on whether the total score will be over or under that number. If the total score is exactly the same as the number set by the sportsbook, the bet is considered a push, and the bettor receives their money back.
For a spread bet, the sportsbook sets a point spread: the number of points the favorite has to win by for a bet on that team to pay out. The underdog works the other way around, since it can lose by as many as that same number of points and a bet on it still wins. A minus sign sits in front of the favorite’s spread, which acts as a handicap. Put another way, in betting terms the favorite starts the game trailing the other team by that number of points.
How Do American Odds Work?
American odds are a way of expressing the likelihood of an outcome in a sporting event or other form of gambling. They work around the number 100 and are displayed with either a plus (+) or minus (-) sign, followed by a number. If the odds are displayed with a plus sign, you would win that amount if you placed a $100 bet. If the odds are displayed with a minus sign, it indicates the amount you would need to bet in order to win $100.
To work out your return from US odds you need to use a one of two simple formulas: If you are betting on the favorite i.e., the team with a minus sign before the odds you use the formula (100/odds)*stake. So you divide 100 by the odds on a selection and, whatever that number is should be multiplied by your stake.
If you are betting on the underdog, the team with a plus before their odds, then the formula is (stake/100)*odds.
An example can be found in the image below where, in the MLB, the Baltimore Orioles take on the Washington Nationals.
In this example, the Baltimore Orioles are priced at -140 in the moneyline, making them the favorites, whereas the Washington Nationals are +130, making them the underdogs. If you placed a $100 bet on the Nationals and they pulled it off, you would secure a profit of $130 ((100/100) x 130) on top of your returned stake.
The Orioles are -140, meaning that you would need to stake $140 to earn a $100 profit. However, should you stake $100 and need to work out your return you would divide 100 by the odds (140) which gives you 0.71 and then multiply that by your stake, to see a profit of $71.
How to Calculate Your Payout
When you bet with plus and minus odds at an online sportsbook, your potential payout based on your stake will typically be automatically displayed, so you won’t need to calculate it yourself. However, if you want to know how to calculate your own payout, it is possible to do so with American odds. Although it may initially seem confusing, it is actually quite simple and can be done in just a few seconds with the help of a calculator.
As American odds have + and – betting there are two formulas depending on if you are betting on the positive or negative odds. We will take a look at an example from an MLB game between the New York Yankees and the Cleveland Guardians.
Profit Formula for Positive American Odds = (Odds/100) x Wager
In this example, the Yankees are +132, therefore:
Profits for a $50 bet on the Yankees = (132/100) x 50 = $66
You would receive a payout of $116 which is your $66 profit plus your $50 stake.
Profit Formula for Negative American Odds = (100/odds) x Wager
In this example the Guardians are -143, therefore:
Profits for a $50 bet on the Guardians = (100/143) x 50 = $34.97
You would receive a payout of $84.97 which is your $34.97 profit plus your $50 stake.
How + and – Works With Different Markets
Sports betting offers a huge variety of markets, and although plus and minus betting with American odds functions consistently across them, there are instances where these symbols can represent something other than the odds themselves. Below, we’ll cover some of the most popular sports betting types and explain how plus and minus signs come into play within each market.
Moneyline
Moneyline betting is one of the most popular and simplest plus and minus betting types to understand. In this type of bet, you are wagering on what player or team is going to win outright.
In most cases, there will be a favorite and an underdog. The favorite will have negative odds and the underdog will have positive odds. In certain games or events, the oddsmakers may think that either team has as good a chance as the other of winning and the odds for either team will be the same.
Point Spread
In spread betting, you are betting on the margin of victory rather than who will win and there are two sets of plus and minuses in spread bets. The first set is for the odds like a moneyline.
The other set of plus and minus is in relation to the points spread. The favorite will have a minus sign and the underdogs will have a plus sign and this relates to the number of points, runs, goals, etc. that a team will need to win by or not lose by more than.
In the example given, the Chicago Bulls are considered the underdogs because the spread is +5.5, which means a bet on them would be a winner as long as they either win the game outright or lose by 5 and a half points or less. The Miami Heat, on the other hand, are the favorites, and they would need to win by 5 and a half points or more for a bet on them to be a winner.
The odds on either bet are the same at -110, which is the standard odds you will find on spread bets whether you are betting on the favorite or the underdog. Although the odds may differ slightly, it’s typically going to be around -110.
However, many sportsbooks will also offer alternate lines and allow you to buy points, meaning a team will either need to win by more or lose by less than the standard spread. The odds on alternate lines can differ significantly.
Over / Under
Over/under bets also known as totals are bets on whether the points, goals or runs will be higher or lower than an agreed-upon value. The most common type of over/under bet is betting on the combined score of a game.
In the image below the total value is set at 228, meaning that if the combined score of the Heat and the Hawks in their game is above 228 the over bet would be a winner and if it’s lower than this value then the under bet would be a winner. If the amount was exactly 228 the bet would be a push.
For over and under wagers, the odds are nearly always pegged at -110, though slight variations can occur. As is the case with spreads, many online sportsbooks also offer alternate lines for totals.
Odds Conversion Table – American Odds vs. Fractional Odds vs. Decimal Odds
In the United States, most sportsbooks have the odds display set to American odds as default. However, most also have the option to change this to either fractional odds or decimal odds. In the table below you can see how the odds are shown across the different formats and the implied probability of the odds.
American Odds (Moneyline)
Fractional Odds
Decimal Odds
Implied Probability
-10000
1/100
1.01
99%
-500
1/5
1.2
83.3%
-400
1/4
1.25
80%
-300
1/3
1.33
75%
-200
1/2
1.5
66.7%
-110
10/11
1.91
52.4%
+100
1/1 (evens)
2
50%
+200
2/1
3
33.3%
+300
3/1
4
25%
+400
4/1
5
20%
+500
5/1
6
16.7%
+600
6/1
7
14.3%
+700
7/1
8
12.5%
+800
8/1
9
11.1%
+900
9/1
10
10%
+1000
10/1
11
9.1%
+2000
20/1
21
4.8%
+5000
50/1
51
2%
+10000
100/1
101
1%
+100000
1000/1
1001
0.1%
FAQs
Before you put any of this into practice with real money, make sure the sportsbook is licensed in your state. Sports betting is only legal in states that have regulated it, and each one keeps a public list of approved operators, for example the New Jersey Division of Gaming Enforcement, the Pennsylvania Gaming Control Board and the New York State Gaming Commission. You must be 21 or older in most states. If betting stops being fun, call or text 1-800-GAMBLER or visit the National Council on Problem Gambling for free, confidential help.
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