Implied Probability Calculator

Enter your betting odds in American, Decimal, or Fractional format along with your Bet Amount to get the Implied Probability, To Win amount, and total Payout. The Implied Probability Calculator converts any odds format into a percentage representing the bookmaker's assessed likelihood of that outcome — helping you spot value bets by comparing implied probability against fair odds.

Odds Format *

Enter negative odds for favorites (e.g. -110) and positive for underdogs (e.g. +150)

Decimal odds include your stake (e.g. 2.00 = even money)

Enter the top number of the fraction (e.g. 10 in 10/11)

Enter the bottom number of the fraction (e.g. 11 in 10/11)

$

Enter the amount you plan to wager

Results

Implied Probability

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To Win

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Total Payout

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Fair American Odds (No-Vig)

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Fair Probability (No-Vig)

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Frequently Asked Questions

How to calculate Implied Probability in betting?

Implied probability is calculated by converting betting odds into a percentage that reflects the bookmaker's assessment of an outcome's likelihood, including their profit margin (vig/juice). The formula differs by odds format: for American odds, for Decimal odds, and for Fractional odds. Once you have the implied probability, you can compare it against your own assessment of the true probability to identify value bets.

How to convert American odds into implied probability?

For negative American odds (favorites), use: Implied Probability = |odds| / (|odds| + 100) × 100. For example, -110 gives 110 / 210 × 100 = 52.38%. For positive American odds (underdogs), use: Implied Probability = 100 / (odds + 100) × 100. For example, +150 gives 100 / 250 × 100 = 40%.

How to convert Decimal Odds into implied probability?

To convert decimal odds to implied probability, divide 1 by the decimal odds and multiply by 100. The formula is: Implied Probability = (1 / Decimal Odds) × 100. For example, decimal odds of 2.50 give an implied probability of (1 / 2.50) × 100 = 40%. Decimal odds always include the return of your stake.

How to convert Fractional Odds into implied probability?

For fractional odds expressed as numerator/denominator, the formula is: Implied Probability = Denominator / (Numerator + Denominator) × 100. For example, odds of 10/11 give 11 / (10 + 11) × 100 = 52.38%. Fractional odds show how much profit you earn relative to your stake.

What is the difference between implied probability and fair probability?

Implied probability includes the bookmaker's profit margin (known as vig or juice), making the total implied probabilities across all outcomes sum to more than 100%. Fair probability (no-vig probability) removes this margin to show the true underlying probability the bookmaker has assigned to each outcome. If your assessment of the true probability is higher than the implied probability, you may have found a value bet.

What does it mean when implied probability is lower than fair probability?

When the offered implied probability of a bet is lower than the calculated fair (no-vig) probability, it suggests the bet may have positive expected value (EV+). This means the bookmaker's vig-adjusted line is slightly in your favor relative to the true probability, which is a key signal professional bettors look for when identifying profitable opportunities.

What is the vig or juice in sports betting?

The vig (short for vigorish) or juice is the bookmaker's built-in commission on a bet. It's the reason that both sides of a standard bet don't each have 50% implied probability — instead, they typically add up to around 104–110%, with the excess representing the bookmaker's edge. For example, a standard -110 line on both sides of a bet gives a total implied probability of about 104.8%.

Can implied probability be used to find value bets?

Yes — comparing implied probability against your own probability estimates is a core strategy for finding value bets. If you believe an outcome has a 55% chance of occurring but the bookmaker's implied probability is only 50%, there is potential value in that bet. Consistently finding and betting on positive EV opportunities is the basis of professional sports betting and sharp betting strategies.