Is implied probability the true chance?
No. It is the break-even rate calculated from the quoted price, not an independent estimate of the event’s true chance. The quoted odds may already include market margin.
Odds & probability
Implied probability
calculator.
Turn any odds line into the break-even chance it represents—then see the formula behind the percentage.
01 / Input
Enter the price
AMERICAN
Formula
100 ÷ (140 + 100)
Positive odds use the amount you could win on a $100 stake.
Try a common line
02 / Readout
Here’s the break-even rate
Implied probability
41.67%
Lower break-evenHigher break-even
American odds+140
Decimal odds2.40
Fractional odds7/5
Break-even rate41.67%
Profit on $100$140.00
Total return$240.00
i
At +140, the price implies a 41.67% break-even rate. You need to win more than that percentage over time to show a long-term profit.
Read it correctly
The percentage behind the price.
Implied probability is a break-even rate—not a prediction of what will happen next.
+
Positive odds
Divide 100 by the odds plus 100.
+140 → 41.67%−
Negative odds
Use the absolute value of the line.
−110 → 52.38%Common questions
Use the number with context
The percentage is useful because it gives you a clean starting point—not because it promises an outcome.
What does -110 mean?
A -110 line implies a 52.38% break-even rate. Winning exactly 52.38% would roughly break even before other costs.
Why can both sides add over 100%?
That difference is the market margin. Comparing both sides of a line helps show what the price is charging you.
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