Implied Probability Calculator | Odds to Probability

Calculate Implied Probability

Enter one betting price to convert it into a percentage.

Result

Entered odds 2.50

Decimal equivalent 2.50

Raw implied probability 40.00%

Break-even probability 40.00%

Potential return for entered stake 250.00

Calculation: 1 ÷ 2.50 × 100 = 40.00%

For one fixed price, raw implied probability and break-even probability have the same numerical value. Potential return is the gross return and includes the original stake.

What the Result Means

Implied probability is the percentage represented by a betting price. For decimal odds, divide 1 by the odds and multiply by 100. Decimal odds of 2.50 therefore represent a 40.00% implied probability.

Decimal, fractional and American odds use different notation, but each format can represent the same underlying price. Converting the price into a percentage makes those formats directly comparable.

Shorter odds correspond to a higher implied probability. Longer odds correspond to a lower implied probability. Decimal odds of 2.00, for example, represent 50%, while decimal odds of 4.00 represent 25%.

The percentage comes from the entered price. It is not an independent forecast of how likely the outcome is to occur.

Formulas by Odds Format

Decimal odds Implied probability = 1 ÷ decimal odds × 100

Fractional odds For A/B odds: implied probability = B ÷ (A + B) × 100

Positive American odds Implied probability = 100 ÷ (odds + 100) × 100

Negative American odds Implied probability = |odds| ÷ (|odds| + 100) × 100

Worked Examples

Decimal odds: 1.80

1 ÷ 1.80 × 100 = 55.56%. A stake of 100 at decimal odds of 1.80 produces a potential gross return of 180.

Fractional odds: 5/2

Odds of 5/2 equal decimal odds of 3.50. The implied probability is 2 ÷ (5 + 2) × 100 = 28.57%. A stake of 100 produces a potential gross return of 350.

American odds: -120

Odds of -120 equal decimal odds of approximately 1.83. The implied probability is 120 ÷ (120 + 100) × 100 = 54.55%. A stake of 100 produces a potential gross return of approximately 183.33.

Scope and Limitations

The calculation uses only the betting price entered above. It converts that price into a percentage and, when a stake is provided, calculates the corresponding gross return.

One price at a time: the result applies only to the selection entered in the calculator.
No full-market assessment: prices for other possible outcomes are not included in this calculation.
No bet-quality verdict: the percentage shows what the price represents, not whether the price is attractive.
Stake does not affect probability: changing the stake changes only the potential return. The implied probability is determined by the odds.

Related Calculators

Bookmaker Margin Calculator Analyse the prices across a complete betting market rather than a single selection. Expected Value Betting Calculator Compare your probability estimate with an available betting price. Bankroll Staking Calculator Calculate stake size separately when the question is bankroll allocation rather than price conversion.

FAQ

What is implied probability in betting?

Implied probability is the percentage represented by a betting price. It converts the odds into a probability on a 0% to 100% scale.

What probability do decimal odds of 2.00 imply?

Decimal odds of 2.00 imply 50%. The calculation is 1 ÷ 2.00 × 100 = 50%.

Why are implied probability and break-even probability the same here?

For a single fixed price they have the same numerical value. Implied probability describes the percentage represented by the odds, while break-even probability is the win rate required to break even at that price over repeated equivalent bets.

Does potential return include the original stake?

Yes. Potential return is stake multiplied by decimal odds, so it includes the original stake. It is not the same as profit.

Can I use fractional and American odds?

Yes. Select the required format before entering the price. Fractional odds can be entered as 3/2 or 5/1, and American odds as +150 or -120.

Does implied probability predict the actual outcome?

No. The percentage is derived from the betting price. It does not independently estimate the true chance that the outcome will occur.