Question 1

What's the difference between decimal and American odds?

Accepted Answer

Both describe the same underlying probability, formatted differently. Decimal odds (e.g. 2.50) show your total return per $1 staked, including your stake back. American odds show how much you'd win on a $100 bet (positive, e.g. +150) or how much you'd need to stake to win $100 (negative, e.g. -150).

Question 2

How do I convert odds to an implied probability?

Accepted Answer

For decimal odds, implied probability is 1 divided by the decimal value, as a percentage — 2.50 decimal odds implies a 40% chance. This tool does that conversion (and the reverse) automatically as you type in any field.

Question 3

Why do the odds add up to more than 100% implied probability?

Accepted Answer

That gap is the bookmaker's or operator's margin, built into the price — it's the same underlying idea as house edge on a casino game, just expressed through the odds instead of a stated percentage.

Odds & Probability Converter

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