How do I convert odds to implied probability?

For positive American odds, divide 100 by the odds plus 100: +200 is 100 / 300 = 33.33%. For negative American odds, divide the odds without the minus sign by themselves plus 100: -150 is 150 / 250 = 60.00%. For decimal odds, divide 1 by the odds: 2.50 is 40.00%. For fractional odds, divide the denominator by the numerator plus the denominator: 5/2 is 2 / 7 = 28.57%.

What is the implied probability of -110?

52.38%, because 110 / (110 + 100) = 0.5238. That is also the share of -110 bets you need to win to break even. With -110 on both sides of a game, the two implied probabilities add up to 104.76%.

Why do implied probabilities add up to more than 100%?

Because the odds include the sportsbook’s margin, also called the vig. With -110 on both sides, each side is 52.38% and together they make 104.76%. The extra 4.76% is the margin. Removing it gives fair probabilities that add up to 100%, here 50% each. The no-vig calculator does that for you.

How do I convert implied probability back to odds?

Decimal odds are 1 divided by the probability: 25% is 1 / 0.25 = 4.00. For American odds, a probability of 50% or more is -(probability / (1 - probability)) × 100, so 60% is -150. Below 50% it is ((1 - probability) / probability) × 100, so 25% is +300. To enter a percentage here, choose Implied probability (%) as the odds format; the calculator shows its decimal odds.

What win rate do I need to break even?

The implied probability of the odds you bet. At -110 you need to win 52.38% of your bets to break even; at +150 you need 40.00%; at -200 you need 66.67%. The calculator shows this as Win Rate Needed, rounded to one decimal place.

How do I use implied probability to find value?

Compare it with your own estimate of the chance. If you think a +150 team wins 45% of the time and the odds imply 40.00%, your estimate is higher than the price and the bet has positive expected value by your numbers. If your estimate is lower than the implied probability, the price is against you.

Implied Probability Calculator: Odds to Percentage

Enter odds in any format to see their implied probability, the decimal odds and the win rate you need to break even.

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Odds (American Format)

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What is implied probability?

Implied probability is the chance of a result that the odds represent, written as a percentage: 1 divided by the decimal odds. It puts every price on the same scale, so -110 and 10/11 both read as 52.38%. Because sportsbook odds include a margin, the implied probabilities of every outcome in a market add up to more than 100%.

Why use an implied probability calculator?

Turn American, decimal, fractional, Hong Kong, Indonesian or Malay odds into a percentage
See the win rate you need to break even at a price
Compare the odds with your own estimate of the chance
See the margin when you add up both sides of a market

How to use the implied probability calculator

1Choose the odds format you have, such as American (-110) or decimal (1.91)
2Enter the odds
3Read the implied probability, the decimal odds and the win rate needed to break even

Example: -110 on both sides

A game priced at -110 on both teams. Each side is 110 / 210 = 52.38% implied probability, and 1.91 in decimal odds. Together the two sides add up to 104.76%, so the market carries a 4.76% margin. Without the margin, each side is 50%.

How to convert odds to implied probability

Positive American odds (+150): 100 / (odds + 100). +150 is 100 / 250 = 40.00%.

Negative American odds (-150): odds / (odds + 100), using the odds without the minus sign. -150 is 150 / 250 = 60.00%.

Decimal odds (2.50): 1 / odds. 2.50 is 40.00%.

Fractional odds (5/2): denominator / (numerator + denominator). 5/2 is 2 / 7 = 28.57%.

Implied probability of common odds

The implied probability of common American odds, which is also the win rate needed to break even at that price.

-300: 75.00%
-200: 66.67%
-150: 60.00%
-110: 52.38%
+100: 50.00%
+150: 40.00%
+200: 33.33%
+300: 25.00%
+500: 16.67%

Implied Probability FAQ

Understanding Probability

Implied probability is the chance of a result that the odds represent, written as a percentage. It is 1 divided by the decimal odds. Odds of +150 are 2.50 in decimal, so their implied probability is 1 / 2.50 = 40.00%. It includes the sportsbook’s margin, so it is a little higher than a fair estimate of the chance.

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