Odds Converter - Decimal, Fractional & American

Convert between decimal, fractional, and American odds formats instantly. See implied probability, potential payout, and profit for any set of odds.

Decimal odds

Used across Europe and Australia. The number represents your total return per unit staked, including your original stake. Decimal 2.50 means EUR 2.50 returned for every EUR 1 bet.

Fractional odds

Traditional in the UK and Ireland. Shown as a fraction (e.g. 3/2), representing profit relative to stake. 3/2 means EUR 3 profit for every EUR 2 staked.

American odds

Standard in the United States. Positive odds (+150) show profit on a EUR 100 stake. Negative odds (-200) show how much to stake for EUR 100 profit.

What is implied probability?

Implied probability converts odds into the percentage chance of an outcome occurring, as implied by the bookmaker's pricing. A fair market would have probabilities summing to exactly 100%. In practice, bookmaker margins (overround) mean the total exceeds 100% — the difference is the bookmaker's edge.

Frequently asked questions

Which odds format is best?

All formats contain the same information. Decimal is often easiest for quick payout calculations, fractional is traditional in the UK, and American odds are standard in the US.

Why does implied probability exceed 100%?

The extra percentage is the bookmaker margin, also called overround or vig. It represents the built-in advantage that ensures the bookmaker profits over the long run.

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