Tool
Odds Calculator
Payout, profit, and implied probability for a single bet — plus the same odds in every format at once.
Enter odds to see the payout and implied probability.
Why the format even matters
American, decimal, and fractional odds are three different ways of writing the exact same thing. American odds (like -110 or +150) are standard at most US sportsbooks. Decimal odds (like 1.91) are common internationally and are what this calculator — and our parlay calculator — actually multiply together under the hood. Fractional odds (like 10/11) are standard in the UK and Ireland. None of them is more honest than another — but if a promo or a friend quotes you odds in a format you don’t normally use, converting it yourself takes ten seconds here instead of trusting someone else’s math.
What implied probability actually means
Every set of odds implies a probability — the chance of that outcome the book is effectively pricing in. Decimal odds of 2.00 imply a 50% chance. That number is worth comparing honestly against how confident you actually are, not just treated as a formality on the way to the payout figure. See Why RTP Actually Matters for the same idea applied to casino games instead of sports odds.
How do you convert American odds to decimal?
For positive American odds, divide by 100 and add 1 (e.g. +150 becomes 2.50). For negative American odds, divide 100 by the absolute value and add 1 (e.g. -110 becomes 1.91). This calculator does the conversion automatically in either direction.
What does implied probability mean?
The probability of an outcome that a given set of odds represents mathematically. Decimal odds of 2.00 imply a 50% chance; odds of 1.50 imply about 67%. It's a useful honesty check against how confident you actually are in a bet.
Is decimal or American odds better?
Neither — they're just two ways of expressing identical odds. American odds are standard at most US sportsbooks; decimal odds are more common internationally and are easier to multiply together for parlay math, which is why calculators tend to convert to decimal internally either way.