Lesson 1
American Odds, Explained
Two numbers, a plus or a minus, and most of what you need to know is in that sign. Here's how to read either one in about five seconds.
Quick answer
Minus odds show what you'd have to risk to win $100 (favorite). Plus odds show what a $100 bet would win (underdog). -180 means risking $180 to win $100; +150 means a $100 bet wins $150.
The sign tells you who's favored
Minus means favorite. Plus means underdog. That's really the whole rule. -180 is a favorite. +150 is an underdog. The number just tells you by how much.
Minus odds: what you'd have to risk to win $100
A minus number tells you how much you'd need to bet to profit $100. -180 means putting up $180 to win $100 (you'd get $280 back total if it hits). The bigger the minus number, the bigger the favorite, and the less you get back for what you risked.
Reading -180
| You risk | $180 |
| You profit | $100 |
| You get back | $280 |
Plus odds: what $100 would win you
A plus number tells you the profit on a $100 bet. +150 means a $100 bet wins you $150 (you'd get $250 back total). The bigger the plus number, the longer the shot, and the more it pays off if it hits.
Reading +150
| You risk | $100 |
| You profit | $150 |
| You get back | $250 |
You don't have to bet $100
Odds get quoted against $100 because it's an easy number to think in, not because that's what you're supposed to bet. The same ratio works at any size. At -180, a $18 bet still profits $10. At +150, a $10 bet still profits $15. Just scale it up or down.
Even money
+100 and -100 mean the same thing: bet $100, win $100. You'll almost never actually see a line sit right there, because sportsbooks build a little margin into both sides no matter what. That margin is the vig, and it's why a "50/50" number almost never actually pays out like one. More on that next.
A smaller stake at two very different prices
| $40 at -125 | $32 profit · $72 returned |
| $25 at +180 | $45 profit · $70 returned |
The plus or minus number defines a ratio; it does not force a $100 stake. At -125, multiply the stake by 100/125. At +180, multiply it by 180/100.
Common mistake: confusing return with profit
A $100 ticket at +150 returns $250, but only $150 of that is profit; the other $100 is the original stake coming back. This distinction matters when tracking ROI. Another common mistake is treating a minus price as a prediction that cannot lose. -300 still implies a loss roughly one time in four before removing the book's margin. Favorites win more often, but an expensive price can make a strong win rate unprofitable.
American odds: frequently asked questions
What does -180 mean in betting odds?
It means risking $180 to win $100 in profit. A winning ticket returns $280: the original $180 stake plus $100 profit.
What does +150 mean in betting odds?
It means a $100 stake wins $150 in profit. A winning ticket returns $250 after the original stake is included.
What is even money in betting?
Even money is +100 or -100. The potential profit equals the stake, although a sportsbook normally adds margin instead of offering both sides at even money.
How do you calculate profit from American odds?
For plus odds, use stake × odds ÷ 100. A $40 stake at +150 profits $60. For minus odds, use stake × 100 ÷ absolute odds. A $40 stake at -180 profits $22.22. Add the original stake only when calculating the total return.