Learn about betting odds, probability, and how to use our calculators effectively
Betting odds represent the probability of an event occurring and determine how much you can win from a bet. They show the ratio between the amount wagered and the potential payout. Higher odds indicate lower probability events with larger potential payouts, while lower odds suggest more likely outcomes with smaller returns.
Example: If a team has odds of 2.50 (decimal), there's approximately a 40% chance they'll win, and a $100 bet would return $250 total ($150 profit + $100 stake).
Decimal odds show your total return for every $1 wagered, including your original stake. They're the most straightforward format for calculating payouts.
How to calculate:
Total Return = Bet Amount × Decimal Odds
Profit = (Bet Amount × Decimal Odds) - Bet Amount
Examples: Odds of 1.50 = $150 return on $100 bet (50% implied probability) | Odds of 3.00 = $300 return on $100 bet (33.33% implied probability)
Fractional odds (also called UK odds) show the ratio of profit to stake. They're written as fractions like 3/1 or 5/2, popular in the UK and Ireland.
How to read: The first number shows potential profit, the second shows the stake required.
3/1 = Win $3 for every $1 bet (plus your $1 stake back)
5/2 = Win $5 for every $2 bet (plus your $2 stake back)
1/4 = Win $1 for every $4 bet (favorites have smaller first numbers)
Moneyline odds use positive (+) and negative (-) numbers to show favorites and underdogs, based on a $100 bet.
Positive odds (+): Show profit on a $100 bet
+200 = Win $200 on a $100 bet (underdog)
+150 = Win $150 on a $100 bet
Negative odds (-): Show how much to bet to win $100
-200 = Bet $200 to win $100 (strong favorite)
-150 = Bet $150 to win $100
Implied probability converts odds into a percentage that represents the bookmaker's assessment of an event's likelihood. It's crucial for identifying value in betting markets.
Formula: Implied Probability = 1 ÷ Decimal Odds × 100
Examples:
Odds of 2.00 = 50% implied probability
Odds of 1.50 = 66.67% implied probability
Odds of 4.00 = 25% implied probability
Why it matters: Compare implied probability with your own assessment to find value bets where you believe the true probability is higher than what the odds suggest.
Converting odds formats helps you:
Compare across bookmakers: Some use decimal, others fractional or moneyline
Calculate payouts easily: Decimal odds are simplest for quick calculations
Understand probability: Convert to percentage for better decision-making
Regional preferences: Use familiar formats for your location
Pro tip: Learn to quickly recognize good value regardless of format - odds of 2.00, 1/1, or +100 all represent the same 50% implied probability.