If you’re just starting out in sports betting, understanding how to read odds is your first crucial step. Betting odds tell you how likely an event is to happen and how much money you can win based on your wager. At first, the numbers may seem confusing, but once you understand the different formats, you’ll be able to place smarter, more confident bets.
The most commonly used odds formats are decimal, fractional, and moneyline (also called American odds). Each one shows the same underlying probability, just in a different way. Sportsbooks may use different formats depending on where you are or what sport you’re betting on, so being familiar with all three helps you adapt quickly.
In this beginner-friendly guide, you’ll learn how to read each odds type, how to calculate potential payouts, and what those numbers are really telling you about the likelihood of an outcome.
Decimal Odds Explained (Popular in Europe and Online)
Decimal odds are the simplest to understand and are used widely across Europe, Canada, Australia, and online sportsbooks. The number shown represents your total return for every unit bet, including your stake.
For example:
- Odds of 2.00 mean that for every $1 you bet, you get $2 back if you win (your $1 stake + $1 profit).
- Odds of 1.50 return $1.50 for every $1 bet (50 cents profit).
- Odds of 3.75 return $3.75 (meaning $2.75 profit).
To calculate your profit:
Profit = (Stake × Decimal Odds) – Stake
So, a $50 bet at odds of 2.50:
- $50 × 2.50 = $125 total return
- $125 – $50 = $75 profit
Decimal odds make it very easy to compare bets. Higher numbers mean lower probability but higher potential profit.
Fractional Odds (Traditional in the UK)
Fractional odds are most common in the UK and Ireland, especially at traditional bookmakers. They show how much profit you’ll make in relation to your stake.
For example:
- 5/1 (read “five to one”) means you win $5 for every $1 bet.
- 1/2 (read “one to two”) means you need to bet $2 to win $1.
- 9/4 means you win $9 for every $4 you bet.
To calculate your total return:
Total Return = Stake + (Stake × Fractional Odds)
So, a $20 bet at odds of 3/1:
- You win $60 in profit and get back your $20 stake
- Total return = $80
Lower fractions like 1/4 represent strong favorites, while longer odds like 12/1 represent underdogs. It takes a little more math than decimal odds, but it becomes second nature with practice.
Moneyline (American Odds)
Moneyline odds are primarily used in the United States and are based on either positive or negative numbers.
- A negative number (e.g., –150) shows how much you need to bet to win $100.
- A positive number (e.g., +200) shows how much profit you’ll make on a $100 bet.
Examples:
- –150: You must bet $150 to win $100 (favorite).
- +200: A $100 bet wins you $200 profit (underdog).
- –110: A standard line for even matchups (common in point spreads).
Formulas:
- For negative odds:
Profit = (100 / Odds) × Stake - For positive odds:
Profit = (Odds / 100) × Stake
So a $50 bet at –200:
- You win $25, plus your original stake
A $50 bet at +300: - You win $150, plus your original stake
Moneyline odds require you to understand who’s favored and by how much. Negative odds mean the outcome is more likely, but the reward is smaller.
What Do the Odds Tell You About Probability?
Odds also reflect implied probability—how likely a sportsbook thinks an event is to happen. You can calculate it like this:
- Decimal odds: 1 / Decimal Odds × 100
- Fractional odds: Denominator / (Denominator + Numerator) × 100
- Moneyline odds:
- Positive: 100 / (Odds + 100) × 100
- Negative: –Odds / (–Odds + 100) × 100
Example: Decimal odds of 2.00 imply a 50% chance of winning.
Sportsbooks build in a margin to ensure profit, so the combined implied probabilities of all outcomes usually exceed 100%.
Tips for Beginners When Reading Odds
- Stick to one format at first—decimal is the most beginner-friendly.
- Compare odds between sportsbooks to find better value (known as line shopping).
- Understand the favorite and underdog by checking if odds are low (favorites) or high (underdogs).
- Don’t just chase big payouts—higher odds come with lower probability.
- Use online calculators if you’re unsure how to calculate profit.
Learning to read betting odds is your first step toward informed and strategic wagering. Whether you prefer decimal, fractional, or moneyline formats, odds tell you how much you can win—and how likely that win really is. Mastering this skill makes the rest of your betting journey far smoother and helps you spot better opportunities in the long run.