Odds Converter
Convert betting odds between decimal, fractional, American (moneyline), and Hong Kong formats. Also displays implied probability and the inverse no-vig fair odds.
What is the Odds Converter?
The odds converter translates betting odds between decimal (European), fractional (UK), American (moneyline), and implied probability formats. Useful when comparing prices across bookmakers in different regions or feeding odds into a prediction model.
How to use the Odds Converter
- Choose the format of the odds you have (decimal / American / fractional / implied probability).
- Enter the odds value.
- All four formats appear instantly on the right.
The formula
Decimal → American:
if decimal >= 2: american = (decimal - 1) * 100
else: american = -100 / (decimal - 1)
Decimal → Implied Probability:
implied = 1 / decimal
Implied → Decimal:
decimal = 1 / impliedWorked example
You see +150 American odds on Mexico to win their World Cup opener. What does that mean in other formats?
- Decimal: 2.50 (a $100 bet returns $250 total - $150 profit + your stake)
- Fractional: 3/2 (bet 2 to win 3)
- Implied probability: 40.00% (Mexico must win at least 40% of the time for this bet to break even)
If you think Mexico will actually win 45%+ of the time, this is a value bet by ~5 percentage points.
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Frequently Asked Questions
What's the difference between decimal and American odds?
Decimal odds show your total payout per unit staked (e.g. 2.50 = $2.50 back per $1 bet). American odds show profit per $100 bet (positive numbers = underdogs, negative = favourites).
How do I calculate implied probability?
Implied probability = 1 / decimal odds. So 2.00 = 50%, 1.50 = 66.7%, 3.00 = 33.3%. Add all outcomes' implied probabilities to find the bookmaker's overround (vig).
What is no-vig (fair) odds?
Bookmakers add a margin to their odds. No-vig fair odds are what the prices would be if the bookmaker took zero margin. Calculated by dividing each implied probability by the total overround.
Do you support Hong Kong / Malay / Indonesian odds?
The converter handles decimal, American, fractional, and implied probability - the four most common formats globally. Hong Kong odds are essentially decimal-1 if you need to convert manually.
How accurate is the conversion?
Exact for decimal ↔ implied probability ↔ American. Fractional odds are returned as a reduced fraction (e.g. 5/2 not 10/4) which is the standard UK display format.
Why does my bookmaker show different odds?
Different bookmakers price events differently based on their model and risk. Lines vary across Bet365, Pinnacle, Betfair, etc. See our [odds API](/odds-api) for live comparison.