American odds are the default format at every US sportsbook. They look strange at first (why −110? why +240?), but they follow two simple rules. Once you know them, you can read any price instantly and calculate payouts in your head.
The two rules
- Negative odds (−): the amount you must bet to win $100.
- Positive odds (+): the amount you win on a $100 bet.
So −150 means you risk $150 to win $100. +150 means you risk $100 to win $150. In both cases you also get your stake back when you win.
Payout examples
| Odds | Bet | Profit if it wins | Total returned |
|---|---|---|---|
| −200 | $100 | $50 | $150 |
| −150 | $60 | $40 | $100 |
| −110 | $110 | $100 | $210 |
| +100 | $100 | $100 | $200 |
| +150 | $40 | $60 | $100 |
| +300 | $25 | $75 | $100 |
The formulas for any stake:
- Negative odds: profit = stake × 100 ÷ |odds|
- Positive odds: profit = stake × odds ÷ 100
Favorites and underdogs
(New to the signs themselves? See what plus and minus mean in betting.)
The minus side is usually the favorite: you risk more to win less because it is more likely to happen. The plus side is the underdog. When both sides show a minus (for example −110 / −110 on a point spread), the market sees them as roughly even and the minus on both is the book's margin.
From odds to implied probability
Every price implies a win chance. This is the most useful conversion in betting.
- Negative odds: probability = |odds| ÷ (|odds| + 100)
- Positive odds: probability = 100 ÷ (odds + 100)
Examples:
- −150 → 150 ÷ 250 = 60%
- +150 → 100 ÷ 250 = 40%
- −110 → 110 ÷ 210 = 52.4%
If you think a bet wins more often than its implied probability, the price is good for you. (Implied probability explained.)
Converting to decimal odds
Decimal odds are easier for math because they include the stake:
- Positive: decimal = 1 + odds ÷ 100 (+150 → 2.50)
- Negative: decimal = 1 + 100 ÷ |odds| (−150 → 1.667)
(Decimal odds explained · Odds converter.)
Quick conversion table
| American | Decimal | Implied % |
|---|---|---|
| −300 | 1.333 | 75.0% |
| −200 | 1.500 | 66.7% |
| −150 | 1.667 | 60.0% |
| −120 | 1.833 | 54.5% |
| −110 | 1.909 | 52.4% |
| +100 | 2.000 | 50.0% |
| +120 | 2.200 | 45.5% |
| +150 | 2.500 | 40.0% |
| +200 | 3.000 | 33.3% |
| +300 | 4.000 | 25.0% |
| +500 | 6.000 | 16.7% |
Why the same bet has different odds at different books
Each sportsbook sets its own prices. On the same game you might see −145 at one book and −130 at another. That is 15 cents of price for the exact same outcome, and over hundreds of bets those differences decide whether you win or lose. (What is line shopping?.) The OddsHype odds screen shows every legal book's price side by side.
Frequently asked questions
What does +200 mean in betting?
A $100 bet at +200 wins $200 in profit, returning $300 in total. The implied probability is 33.3%.
What does −300 mean in betting?
You must bet $300 to win $100 in profit. The implied probability is 75%.
Is it better to bet plus or minus odds?
Neither is better on its own. What matters is whether the price beats the true probability. A −200 bet can be a great value and a +300 bet can be terrible.
What does even money mean?
Even money is +100 (decimal 2.00): you win the same amount you risk.