You open a sportsbook app before Sunday’s game. You see this next to the Chiefs and Raiders: Chiefs -180, Raiders +150. There is no context. No explanation. Just numbers with symbols stuck in front of them, like a code nobody handed you the key to.
The first time I saw a board like that, I closed the app. I did something else for an hour instead. It looked harder than it really was.
How to read American betting odds comes down to two things: the sign in front of the number and what that number says about a $100 bet. This is all there is to it. Understand this, and everything else is basic math. There is no special app or magic formula; it’s just some simple math that you know how to do.
What the plus and minus signs mean
Minus marks the favorite. Plus marks the underdog. That rule never changes, no matter the sport.
-180 Chiefs means that the sportsbook believes that they will win. +150 Raiders means that they are considered the underdog, at least from the perspective of this line. The books derive these figures based on their likelihood of winning. Then they add a small fee for themselves. Sportsbooks are businesses, after all. We will get to that fee soon, because it matters more than most people think.
Here is what trips people up. The minus number tells you what you would need to risk to win $100. The plus number tells you what a $100 bet would actually pay you. Nobody is forcing you to bet $100. It is just the number everything else is based on, whether you bet five dollars or five hundred.
Try it with baseball too. Yankees -140 against Red Sox +120 works the exact same way. The team with the minus sign is the favorite. The team with the plus sign pays more if they pull off the win. Same signs, same math, whether it’s football, baseball, or a UFC card on a Saturday night.
How to calculate your payout
Math gets easier once you plug in real numbers.
Take -180. Now divide 100 by 180, then multiply the result by your wager. If you placed a bet of $50 on the Chiefs, you will make about $27.78. The $50 added to the amount gives you a total of $77.78. Not much of a win there for going with the favorite.
Also, plus odds can be calculated using the opposite process of the minus odds. Now divide the number by 100, and multiply the result by your wager. Your same $50 wager on the Raiders at +150 will give you $75.
Underdogs pay more when they win. There is no trick to it. A sportsbook charges more because the outcome is less likely. Whether that extra money is worth chasing depends on how sure you actually are, not which team is more famous.There’s a faster way to eyeball this without doing the full formula. Bigger minus numbers mean smaller payouts, because the team looks like a safer bet. Bigger plus numbers mean bigger payouts, because the team looks like a bigger long shot. You do not always need the full formula to get a rough idea of what a bet is worth.
Reading odds as implied probability
Odds are not just a payout number. They also tell you how likely the sportsbook thinks something is to happen.
For a minus number, divide it by itself plus 100. Then multiply by 100. Run -180 through that, and you get about 64%. Plus numbers work in reverse. Divide 100 by the number plus 100, then multiply by 100. Do that with +150, and you get about 40%.
Now add both numbers together. You would expect 100%. Instead, you get 104%.That extra 4% has a name. It is called the vig, or sometimes the juice. It is the reason a sportsbook stays in business, even when equal money is bet on both sides. Think of it like a small cover charge baked into every bet on the board.
A quick example from a real game
Los Angeles Lakers: – 130; Boston Celtics: + 110. For $20 placed on the Lakers to win, you receive around $15.38 in return, assuming the Lakers win the game. That’s pretty much it. The same $20 placed on the Boston Celtics would give you $22 should this team pull off an upset.
The true essence of making bets in sports lies not in the ability to choose winners, but in identifying when the reading that you have about a team is worth more than the implied chances suggested by the odds. Are you sure that the Celtics have better than a 47% chance to win? Then you have yourself a good bet regardless of which side is favored. Slowing down for ten seconds before you tap the bet button fixes most of that.
Comparing odds across sportsbooks
One book has the Chiefs at -180. Another has them at -170. Same game. Same team. Ten points apart. That gap changes what lands in your account.
Shopping around sounds boring, but it is worth it. jet10casino.net lists current lines across many markets. Finding the better number on the same game takes seconds instead of five open tabs and a headache.
Two people can pick winners at the same rate all season. Yet they can end up with very different amounts of money. The only difference is one of them checked for a better price before betting.
Over a whole season, those small gaps add up. A few extra dollars here and there does not feel like much on one bet, but it turns into real money over a hundred bets.
Making sense of the board yourself
Learn how to read American betting odds once, and a sportsbook page stops looking like noise. Minus means favorite. “Plus” means underdog. Both are based on that same $100 number, no matter what you actually bet.
Practice beats memorizing every time. Pull up tonight’s games. Look at the moneyline. Try to work out the payout yourself before the sportsbook’s odds payout calculator does it for you. Skip a couple of times, and it’ll suddenly get easier for you than you think. Curious to see how the numbers change as the day of the game draws near? jet10casino.net shows live odds you can practice reading in real time.
Frequently Asked Questions
What does the minus sign mean?
Favorite. It shows what you would need to risk to win $100. At -200, you are risking $200 to win $100. No more, no less.
What does the plus sign mean?
Underdog, and the payout on a $100 bet. A team at +200 turns $100 into $200 if it wins.
Why do sportsbooks add a vig?
Because that is how they make money. Add up the implied probability on both sides of a bet, and it comes out a bit over 100%. That extra bit is the house’s cut, win or lose, every time.
Do I have to bet exactly $100?
No. This is simply the point of reference for the entire system. Bet five dollars or five hundred, and the payout ratio will be the same.
Should I always bet the favorite since they win more often?
Not necessarily. The favorites win more frequently but do not pay much. The important thing is whether you can beat the odds with your personal reading of the situation.
