Reading Odds: American, Decimal & Fractional
Definition
Reading Odds: American, Decimal & Fractional in sports betting the three ways odds are displayed - and how to read each one.
Think of it this way
Like Celsius vs Fahrenheit for temperature. Same information, different scales. 32F = 0C = freezing. -150 odds = 1.67 decimal = same bet.
Reading Odds: American, Decimal & Fractional
Before you can bet, you need to read the language. Odds come in three formats, and understanding them is your first skill.
The Three Formats
Different sportsbooks and countries use different formats. Here's the same 60% probability bet in each:
| Format | Example | Used In |
|---|---|---|
| American | -150 | United States |
| Decimal | 1.67 | Europe, Australia, Canada |
| Fractional | 2/3 | United Kingdom |
All three say the same thing. Let's break them down.
American Odds (US Standard)
This is what you'll see on most US sportsbooks. It uses plus (+) and minus (-) signs.
Minus Odds (Favorites)
-150 means: Bet $150 to win $100.
The number tells you how much you need to risk to win $100.
| Odds | You Bet | You Win | Total Return |
|---|---|---|---|
| -100 | $100 | $100 | $200 |
| -150 | $150 | $100 | $250 |
| -200 | $200 | $100 | $300 |
| -300 | $300 | $100 | $400 |
The bigger the minus number, the bigger the favorite.
Plus Odds (Underdogs)
+150 means: Bet $100 to win $150.
The number tells you how much you win on a $100 bet.
| Odds | You Bet | You Win | Total Return |
|---|---|---|---|
| +100 | $100 | $100 | $200 |
| +150 | $100 | $150 | $250 |
| +200 | $100 | $200 | $300 |
| +500 | $100 | $500 | $600 |
The bigger the plus number, the bigger the underdog.
The Key Rule
- Minus (-) = Favorite = Bet more to win $100
- Plus (+) = Underdog = Bet $100 to win more
Decimal Odds (International)
Decimal odds show your total return per $1 bet (including your stake).
1.67 means: For every $1 you bet, you get back $1.67 total.
Converting to Profit
Your profit = (Odds - 1) x Stake
| Odds | Bet $100 | Total Return | Profit |
|---|---|---|---|
| 1.50 | $100 | $150 | $50 |
| 2.00 | $100 | $200 | $100 |
| 2.50 | $100 | $250 | $150 |
| 3.00 | $100 | $300 | $200 |
Why Some Prefer Decimal
- Simpler math (just multiply)
- No plus/minus confusion
- Easy to compare across bets
2.00 = Even money (same as +100 or -100 American)
Fractional Odds (UK Style)
Fractional odds show profit relative to stake.
3/1 (read "three to one") means: Win $3 for every $1 bet.
| Odds | You Bet | You Win | Total Return |
|---|---|---|---|
| 1/1 (evens) | $100 | $100 | $200 |
| 2/1 | $100 | $200 | $300 |
| 5/1 | $100 | $500 | $600 |
| 1/2 | $100 | $50 | $150 |
Reading Fractional Odds
- 2/1 = You win 2 for every 1 you stake (profit is 2x your bet)
- 1/2 = You win 1 for every 2 you stake (you're betting on a favorite)
Quick Conversion Cheat Sheet
| American | Decimal | Fractional | Implied Prob |
|---|---|---|---|
| -200 | 1.50 | 1/2 | 66.7% |
| -150 | 1.67 | 2/3 | 60% |
| -110 | 1.91 | 10/11 | 52.4% |
| +100 | 2.00 | 1/1 | 50% |
| +150 | 2.50 | 3/2 | 40% |
| +200 | 3.00 | 2/1 | 33.3% |
| +300 | 4.00 | 3/1 | 25% |
DMP Note
DMP uses American odds throughout the platform because most US sportsbooks do. But understanding all formats helps you:
- Compare lines across international books
- Read odds from any source
- Convert mentally when needed
You now speak the language. Every odds format tells you the same thing - just in different ways.
How DMP uses this
DMP displays American odds since that's what US sportsbooks use. Understanding all formats helps you compare lines anywhere.
Common mistake
Getting confused by minus vs plus. Remember: minus = favorite (you risk more), plus = underdog (you win more).
After this lesson
You can read odds in any format and understand what they mean.
Apply These Concepts in Real Betting Markets
The DumbMoneyPicks app scans thousands of player prop lines to find potential +EV opportunities and role shifts caused by injuries.
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