Odds Calculator

Convert between American, decimal, and fractional odds instantly

American Odds → Probability
Example: -110, +200, -150, +300
→

Probability

-
Probability → American Odds
%
Example: 52.4, 60, 33.3, 75
→

American Odds

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Decimal Odds → Probability
Example: 1.91, 2.00, 1.50, 3.00
→

Probability

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Probability → Decimal Odds
%
Example: 52.4, 60, 33.3, 75
→

Decimal Odds

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Probability → Fractional Odds
%
Example: 60, 33.3, 50, 25
→

Fractional Odds

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Fractional Odds → Probability
Numerator
/
Denominator
Example: 3/2, 2/1, 1/2, 5/1
→

Probability

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Common Odds Reference
-110 = 1.91 decimal = 10/11 = 52.4%
Standard point spread / totals
+200 = 3.00 decimal = 2/1 = 33.3%
Underdog — 1 in 3 chance
-200 = 1.50 decimal = 1/2 = 66.7%
Strong favorite — 2 in 3 chance
+100 = 2.00 decimal = 1/1 = 50.0%
Even odds — coin flip
-150 = 1.67 decimal = 2/3 = 60.0%
Moderate favorite
How Odds Work

American Odds: Negative (-110) means favorite — bet that amount to win $100. Positive (+200) means underdog — bet $100 to win that amount.

Decimal Odds: Your total payout per $1 wagered. Odds of 2.50 mean a $10 bet returns $25 total ($15 profit + $10 stake).

Fractional Odds: Show profit relative to stake. Odds of 3/1 mean $3 profit for every $1 bet.

Implied Probability: The real percentage chance the odds represent. Compare this to your own estimate to find value bets.