Understanding how sports betting odds work is one of the first steps toward becoming a confident bettor. Odds tell you two key things: how likely an outcome is to happen and how much you can potentially win. Whether you bet online, at a casino, or through a sportsbook, learning how to read different formats of odds is essential.
Types of Sports Betting Odds
There are three main formats used around the world. Each represents the same concept — probability and payout — but in a different way.
- American (Moneyline) Odds – Common in the United States
- Fractional Odds – Used mostly in the United Kingdom and Ireland
- Decimal Odds – Standard in Europe, Canada, and Australia
All three formats lead to the same payout amount when converted correctly.
How American (Moneyline) Odds Work
Understanding Favorites and Underdogs
Moneyline odds show how much you need to risk or how much you can win, based on a $100 reference point.
- Favorites have a minus sign (−). The number shows how much you must bet to win $100.
- Underdogs have a plus sign (+). The number shows how much you’ll win for every $100 wagered.
Example:
If a basketball team is listed at −150, you need to bet $150 to win $100.
If another team is +200, a $100 bet returns $200 profit (plus your $100 stake).
The bigger the difference between the two sides, the more heavily favored one team is.
Real-World Example
Suppose Team A is −300 and Team B is +250.
A $300 bet on Team A would return $400 total ($100 profit).
A $100 bet on Team B would return $350 total ($250 profit) if they pull off the upset.
How Fractional (British) Odds Work
Fractional odds, often seen as 6/1 or 9/2, show the ratio of profit to stake.
Example:
At 6/1 (six to one), you win $6 for every $1 bet — plus your stake back.
So, a $10 wager at 6/1 returns $70 total ($60 profit + $10 stake).
Interpreting Fractional Odds
If the Brooklyn Nets are listed at 13/5, and the Milwaukee Bucks at 7/1, the Nets are favorites because their odds offer a smaller potential profit, implying a higher probability of winning.
Calculation Formula:
Total Return = (Stake × (Numerator ÷ Denominator)) + Stake
How Decimal (European) Odds Work
Decimal odds display the total payout per $1 wagered, including your stake.
They are the simplest format for quick calculations.
Formula:
Total Return = Stake × Decimal Odds
Example:
If the decimal odds are 4.00, a $100 bet pays $400 total ($300 profit).
If the odds are 1.50, the same bet pays $150 total ($50 profit).
Understanding Probability
Lower decimal odds mean the outcome is more likely.
For instance, odds of 1.30 reflect a strong favorite, while 4.00 indicates an underdog.
Common Bet Types
Over/Under (Totals)
A wager on whether the combined score will be over or under a number set by the sportsbook.
Parlay (Accumulator)
Multiple bets combined into one. Every selection must win for the parlay to cash, making it riskier but with higher payouts.
Teaser
A modified parlay that lets you adjust point spreads in your favor. It lowers the risk but also reduces the payout.
Proposition (Prop) Bets
Bets on specific outcomes within a game — for example, which player scores first or how many home runs a team hits.
How Odds Affect Payouts
The higher the odds, the bigger the payout — but also the lower the probability of winning.
For example:
- 5/1 means $5 profit per $1 bet.
- 7/2 means $7 profit per $2 bet.
Always balance potential return with risk and realistic probability.
What the Plus (+) and Minus (−) Mean
- A plus sign (+) marks the underdog and tells you how much you’d win on a $100 bet.
- A minus sign (−) marks the favorite and shows how much you need to bet to win $100.
Example: +200 means bet $100 to win $200. −150 means bet $150 to win $100.
Vegas Odds Explained
Vegas odds are simply American moneyline odds originating from Las Vegas sportsbooks.
They may include point spreads — the margin of victory predicted by bookmakers — allowing bets not only on who wins but by how much.
Practical Tips for Reading Odds
- Start small: practice with low stakes while learning.
- Track implied probability to compare value.
- Bet on sports you understand for better judgment.
- Avoid emotional betting — rely on logic, not loyalty.
Odds don’t guarantee results, but understanding them improves your decision-making.
The Bottom Line
American, British, and European odds are simply different ways to express the same concept — probability and payout.
Mastering all three formats helps you compare value across sportsbooks and make informed choices.
If you or someone you know struggles with gambling, contact the National Problem Gambling Helpline at 1-800-GAMBLER or visit ncpgambling.org/chat for support.
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FAQ: Common Questions About Sports Betting Odds
What are the three main types of sports betting odds?
The three main types are American (moneyline), Fractional (British), and Decimal (European) odds. Each format shows the same information about probability and payout, just in a different way depending on regional preference.
What does +200 mean in betting odds?
A +200 moneyline means you would win $200 on a $100 bet if your pick wins. The plus sign indicates the underdog, showing how much profit you earn for every $100 wagered.
What does -150 mean in sports betting?
A -150 moneyline represents the favorite. You must bet $150 to win $100 in profit. Negative odds show how much you need to risk to make $100, reflecting higher win probability.
Which odds format is easiest to understand?
Most beginners find decimal odds easiest because they include your total return in a single number. For example, odds of 2.50 mean a $10 bet would return $25 total ($15 profit + $10 stake).
How do odds determine payouts?
Odds indicate both the likelihood of an outcome and your potential payout. Higher odds mean a lower chance of winning but a larger profit, while lower odds indicate a stronger favorite with smaller returns.