American vs Decimal Odds: How to Read and Convert Betting Odds
Odds are just a price written in a format. American odds (-110, +150) dominate US sportsbooks; decimal odds (1.91, 2.50) are standard almost everywhere else, and many offshore books let you switch between them. Our odds page has a Decimal / American toggle for the same reason. Once you can read both, you can compare any two books at a glance.
How to read American odds
American odds are built around $100.
- Negative number (favorite): how much you must risk to win $100. At -110, you risk $110 to win $100.
- Positive number (underdog): how much you win on a $100 stake. At +150, a $100 bet wins $150.
- +100 / -100: an even-money bet. Risk $100 to win $100.
The bigger the negative number, the bigger the favorite. The bigger the positive number, the bigger the underdog.
How to read decimal odds
Decimal odds show your total return per $1 staked, stake included.
- 1.909 means a $1 bet returns $1.909 in total: your $1 back plus $0.909 profit.
- 2.50 means a $100 bet returns $250: $100 stake plus $150 profit.
Anything under 2.00 is a favorite, anything over 2.00 is an underdog, and 2.00 is even money. To get profit only, subtract 1 and multiply by your stake.
Converting between the two
American to decimal
- Negative odds: 1 + (100 ÷ odds), ignoring the minus sign. -110 → 1 + 100/110 = 1.909
- Positive odds: 1 + (odds ÷ 100). +150 → 1 + 150/100 = 2.50
Decimal to American
- Decimal 2.00 or higher: (decimal − 1) × 100, shown as plus. 2.54 → +154
- Decimal below 2.00: −100 ÷ (decimal − 1). 1.58 → −100 / 0.58 = −172
Quick conversion chart
| Decimal | American | Implied probability |
|---|---|---|
| 1.58 | -172 | 63.3% |
| 1.71 | -141 | 58.5% |
| 1.78 | -128 | 56.2% |
| 1.909 | -110 | 52.4% |
| 2.00 | +100 | 50.0% |
| 2.19 | +119 | 45.7% |
| 2.50 | +150 | 40.0% |
| 2.54 | +154 | 39.4% |
Implied probability: the number inside every price
Every price carries a probability. With decimal odds it is simply 1 ÷ decimal: 1.58 implies a 63.3% chance. With American odds:
- Negative: risk ÷ (risk + 100). -110 → 110 / 210 = 52.4%
- Positive: 100 ÷ (odds + 100). +150 → 100 / 250 = 40%
Add up the implied probabilities of both sides of a game and you will get more than 100%. That overflow is the sportsbook's cut, the vig. At -110 on both sides the total is 104.8%. We break that down in what is vig, and the win rate you need to overcome it is in break-even win rate.
Which format should you use?
Whichever lets you compare fastest. Decimal is easier for math (multiply by your stake, done) and for spotting the better of two prices: higher decimal = better for you, always. American is what most US bettors grew up with. The prices are identical either way.
Betting odds FAQ
What does -110 mean in betting?
You risk $110 to win $100. If the bet wins you get $210 back in total. It is the standard price on spreads and totals at most US-facing books.
What does +200 mean?
A $100 bet wins $200 in profit, $300 returned in total. The implied probability is 33.3%.
Is 1.5 in decimal odds good?
It depends on the true chance of the outcome. 1.50 implies 66.7%. If you believe the team wins more often than that, the price has value; if not, it does not.
How do I convert decimal odds to American quickly?
If the decimal is 2.00 or higher, subtract 1 and multiply by 100 for a plus number. If it is below 2.00, divide -100 by (decimal minus 1).
Why do two books show different odds for the same game?
Each book sets its own prices and its own margin. Comparing them and taking the best number on every bet is one of the simplest edges available. That is what our odds page is for.
Bet within your limits
Understanding odds helps you avoid bad prices; it does not remove risk. Only stake what you can afford to lose. 18+ only.