Odds converter
American, decimal, fractional and implied probability are four ways of writing the same price. Enter any one and the rest follow.
Enter any one format
Type in one box. The other three update as you type.
- American
- —
- Decimal
- —
- Fractional
- —
- Implied probability
- —
- Hong Kong
- —
- Profit on 100 staked
- —
- Total return on 100
- —
What the number means
All four formats describe the same thing: how much you get back if the bet wins. Decimal states the total return per unit staked, American states the profit on 100 (positive) or the stake needed to win 100 (negative), fractional states profit against stake, and implied probability restates the price as a percentage.
The conversion is exact and reversible. Small rounding differences appear
because American odds are usually quoted in whole numbers while decimal is
quoted to two or four places, so -110 and 1.91 are
not quite the same price. That gap is real money over a large number of bets,
which is why the decimal column here is shown to four places.
Where it misleads
Implied probability from a single quoted price is not the market's estimate
of the outcome. It includes the operator's margin, so the implied
probabilities of both sides of a two-way market add up to more than 100%. Two
sides at -110 imply 52.38% each, which totals 104.76%. Stripping
that margin out is a separate step, and the
vig calculator does it.
American odds strictly between -100 and +100 do
not exist. +100 and -100 are the same price
(decimal 2.00, even money). If you type something inside that range this page
tells you instead of quietly showing a wrong answer.
Read next
Guides on this site that use the same maths.