The American odds format has a branding problem. It calls itself “American” but manages to confuse more Americans than any other system. Two symbols — a plus and a minus — carry the entire weight of conveying risk, reward, and probability, and they do it in a way that feels designed to trip up beginners. One side tells you what you need to risk. The other tells you what you stand to win. And neither side uses the same math as the other.
Once you crack the code, though, American odds become second nature. They are the default language on every major U.S. sportsbook, and they appear on every NFL, NCAA, and soccer betting line offered to American bettors. This article breaks down exactly how the plus and minus signs work, walks through the payout formulas, and shows you how to use these numbers to make smarter decisions with your money.
Pricing Heavy Favorites with Minus American Odds
When you see a minus sign in front of a number, you are looking at the favorite. The number tells you exactly how much money you need to risk in order to win $100 in profit. It is a measure of cost, not reward.
Take a line of -150 on the Kansas City Chiefs. That means you need to wager $150 to earn $100 in profit. If the Chiefs win, your sportsbook pays back your $150 stake plus $100, totaling $250 in your account. The sportsbook is telling you the Chiefs are more likely to win, and that likelihood comes with a price — you put up more money than you stand to gain.
The formula for calculating your profit on a negative American odds bet is: Profit = (Stake / Absolute Odds Value) x 100. If you bet $75 at -150, your profit calculation is (75 / 150) x 100 = $50. Your total return would be $125 — your $75 stake plus $50 profit. The total return formula is simply Stake + Profit, or alternatively: Total Payout = Stake x (1 + 100 / Absolute Odds Value).
The deeper the minus number goes, the more the sportsbook expects that team to win. A line of -300 means you risk $300 to win just $100. At -600, you are putting up $600 for $100 in profit. Those kinds of lines appear on heavy mismatches — a top-ranked NFL team hosting a team that has won two games all season, for example. The payout looks unimpressive, but the implied probability is high. At -300, the sportsbook believes the favorite wins about 75% of the time. At -600, that number climbs to roughly 85.7%.
The Plus Sign: Pricing Underdogs
The plus sign marks the other side of the line — the underdog. Here, the number tells you how much profit you earn on a $100 bet. The logic reverses completely from the minus side, which is where most of the confusion lives.
A line of +200 on the Detroit Lions means that a $100 wager returns $200 in profit if Detroit wins. Your total payout comes to $300 — the $200 profit plus your original $100 stake. The sportsbook is saying Detroit is less likely to win, and to compensate for that risk, they offer you a bigger return.
The formula for positive odds: Profit = (Stake x Odds Value) / 100. So a $50 bet at +200 earns (50 x 200) / 100 = $100 in profit. Total payout: $150. At +350, a $50 bet earns (50 x 350) / 100 = $175 in profit, for a total return of $225. The bigger the plus number, the bigger the perceived gap between the two teams — and the bigger the potential reward.
Plus odds in football betting range from small underdogs at +110 or +120 (nearly a coin-flip game, just slightly less likely to win) all the way to massive long shots at +1000 or higher. You will see plus-1000 and beyond primarily in futures markets — such as a rebuilding team’s odds to win the Super Bowl at the start of the season. In weekly game markets, plus-300 to plus-500 covers the range of significant underdogs, while anything above that suggests a near-impossible upset in the eyes of the bookmaker.
Real-World American Odds in Action
Understanding the formulas is one thing. Seeing them play out across an actual NFL betting board is another. Consider a Week 8 matchup where the sportsbook posts the following moneyline:
- Philadelphia Eagles: -180
- Dallas Cowboys: +155
The Eagles at -180 require a $180 wager to win $100 profit. The implied probability is 180 / (180 + 100) = 64.3%. The Cowboys at +155 offer $155 profit on a $100 bet, with an implied probability of 100 / (155 + 100) = 39.2%. Add those up: 64.3% + 39.2% = 103.5%. That extra 3.5% above 100% is the sportsbook’s built-in margin — the vigorish.
Now consider a point spread line on the same game:
- Eagles -3.5 at -110
- Cowboys +3.5 at -108
Both sides carry minus odds here because the spread is designed to make the contest roughly even. At -110, you risk $110 to win $100. At -108, you risk $108 to win $100. The sportsbook profits regardless of which side covers because each bettor pays slightly more than they stand to win. The slight difference between -110 and -108 reflects a minor imbalance in where the money is flowing — the book adjusted the Cowboys’ side to attract more action.
This asymmetry appears everywhere. Totals markets, props, futures — every line carries some version of this margin. Understanding how American odds display it helps you recognize when you are paying a steep price and when the margin is thinner than usual.
The Vig: What American Odds Do Not Tell You Directly
American odds communicate payout information, but they obscure one critical piece of data: the true cost of placing the bet. That cost is the vig, and it lives in the gap between the two sides of any market.
In a theoretically fair market — no sportsbook edge — a 50/50 outcome would be priced at +100 on both sides. Bet $100, win $100. But sportsbooks do not offer +100/+100. They offer -110/-110, which means each bettor risks an extra $10 for the same potential $100 profit. That $10 per side is the vig. Over thousands of bets, the sportsbook collects that margin regardless of outcomes, as long as they balance action on both sides.
The vig fluctuates. Standard juice on NFL spreads and totals sits at -110, but you will occasionally see -105 on promotions, or -115 on high-demand markets. Some sportsbooks offer reduced juice as a permanent feature, typically at -105 or -107, which saves bettors real money over time. The difference between paying -110 and -105 across hundreds of bets compounds significantly. A bettor placing 500 wagers a year at -105 instead of -110 saves roughly 2.3% of total handle, which translates to hundreds or thousands of dollars depending on stake size.
American odds make the vig visible if you know where to look, but they never explicitly label it. You have to calculate implied probability on both sides and add them up. The amount above 100% is the vig percentage, and lower is always better for the bettor.
The Sign Language of Sportsbooks
Here is something nobody tells beginners: the plus and minus signs are not just math symbols. They are a communication system, and the sportsbook is always talking.
When a line moves from -3 (-110) to -3.5 (-105), the book is saying “we need more people on this side, so we are sweetening the price.” When an underdog shifts from +200 to +180, the book is saying “too much money came in on this team, and we are shortening the payout to manage our risk.” Every movement in American odds tells a story about money flow, public perception, and the bookmaker’s own risk exposure.
Experienced bettors read line movement the way traders read stock tickers. A sudden shift from -150 to -170 on a favorite might indicate sharp money — large bets from professional bettors who typically have better information or models. A slow drift from +130 to +145 on an underdog could mean the public is hammering the favorite, and the book is adjusting to balance its liability. None of this is hidden. It is all right there in the plus and minus signs, updating in real time.
The next time you look at a betting board and see -110 or +250, do not just see a number. See a price tag. See a probability estimate. See the sportsbook’s opinion about what is going to happen, expressed in the most compact financial shorthand that exists in sports. Your job, once you understand the language, is to decide when that opinion is wrong.
