📊 Implied Probability Calculator
Convert between different odds formats and see the implied probability.
Odds Formats
Implied Probability
What This Means
These odds suggest a 50% chance of the event occurring, according to the bookmaker's prices (including their margin).
About Implied Probability
Implied probability is the likelihood of an outcome occurring based on betting odds. It's used to assess betting value and convert between odds formats.
Understanding Odds Formats
A £1 bet at 5/1 odds returns £5 profit plus £1 stake = £6 total
A £1 bet at 6.00 odds returns £6 total (including stake)
+500 means a $100 bet wins $500 profit; -200 means you bet $200 to win $100
Conversion Formulas
(1 / decimal odds) × 100
Positive odds: 100 / (odds + 100) × 100
Negative odds: |odds| / (|odds| + 100) × 100
denominator / (numerator + denominator) × 100
Frequently Asked Questions
What is the bookmaker's margin?
When you add up the implied probabilities for all possible outcomes in an event, they usually total more than 100%. This excess is the bookmaker's margin (also called overround or vig), which represents their built-in profit.
How do I find value bets using implied probability?
Compare the implied probability from the odds to your own assessment of the true probability. If you believe the true probability is higher than the implied probability, that bet may offer value. For example, if odds imply 40% but you assess 50%, you have positive expected value.
Why does higher implied probability mean lower payout?
Higher implied probability means the bookmaker considers the outcome more likely to occur. Since there's less risk for the bettor, the potential payout is lower. Conversely, lower implied probabilities (longshots) offer higher potential returns to compensate for the increased risk.
Usage Tips
- Higher implied probability means lower potential payout
- Total implied probability over 100% indicates bookmaker margin
- Compare implied probabilities across bookmakers to find value
- Use this calculator to quickly convert between different odds formats