Odds Converter Tool and Helpful Charts

This handy tool instantly converts odds from one format to the next. It also calculates the implied probability of a set of odds. It鈥檚 super easy to use and it鈥檚 completely free.

ODDS CONVERTER
American Odds:
Decimal Odds:
Fractional Odds:
Implied Probability:

Not sure what鈥檚 going on here? If you鈥檙e not familiar with sports betting odds and how they work, please take a look at our page that explains odds in sports betting flawlessly.

Alternatively, we鈥檝e provided a quick overview of each of the different odds formats further down this page. We鈥檝e explained implied probability too. Additionally, there鈥檚 an odds conversion chart for easy reference. And last but not least, there鈥檚 a list of calculations needed to convert the different formats, for anyone who鈥檚 interested in mathematics behind everything.

About Moneyline Odds

  • Also known as American odds.
  • Used primarily in the United States.
  • Can be positive or negative.
  • When positive, the number shows how much you could win from a $100 stake.
  • When negative, the number shows how much must be staked to win $100.
$10Stake
Odds of
+100
$20Potential Return

($10 win + $10 initial stake)

$10Stake
Odds of
+150
$25Potential Return

($15 win + $10 initial stake)

$10Stake
Odds of
-200
$15Potential Return

($5 win + $10 initial stake)

About Decimal Odds

  • Also known as European odds.
  • Used primarily in Europe, but increasingly popular worldwide.
  • Are always a number greater than 1.00.
  • The number shows the multiple of your stake returned, including your initial stake.
$10Stake
Odds of
2.00
$20Potential Return

($10 win + $10 initial stake)

$10Stake
Odds of
5.00
$50Potential Return

($40 win + $10 initial stake)

$10Stake
Odds of
1.50
$15Potential Return

($5 win + $10 initial stake)

About Fractional Odds

  • Also known as British odds or traditional odds.
  • Used primarily in the United Kingdom, but their use is declining.
  • The first number in the fraction shows you how much you can win per amount in the second number staked.
$10Stake
Odds of
2/1
$30Potential Return

($20 win + $10 initial stake)

$10Stake
Odds of
5/2
$35Potential Return

($25 win + $10 initial stake)

$10Stake
Odds of
1/2
$15Potential Return

($5 win + $10 initial stake)

What is Implied Probability?

Implied probability is basically the conversion of odds into a percentage. That percentage then shows the likelihood of an outcome happening based on the size of the odds. High odds suggest a low probability of something happening, while low odds suggest a high probability of something happening.

For example, imagine a tennis player is +200 to win an upcoming match. This would be 3.00 in decimal odds, and 2/1 in fractional odds. The implied probability for these odds is 33.33%. In this example, the odds suggest that the player has a 33.33% chance of winning the match.

This doesn鈥檛 mean that this is the player鈥檚 EXACT chance of winning the game.

In sports, the probability of something happening is usually subjective. There are several factors to take into account and there鈥檚 always a chance of the unexpected. No one can state definitively the exact probability of a player or team winning a game they鈥檙e taking part in. There鈥檚 an element of personal opinion involved.

Calculating the implied probability is useful though. It helps us decide whether or not we think a bet offers any positive value. We should always look for positive value when betting, and it exists when our estimated probability of an outcome happening is greater than the implied probability that the odds on that outcome suggest.

Confused? Don鈥檛 worry! It鈥檚 not as complicated as it may seem. To make this easier to understand, let鈥檚 continue with the example of the tennis player at +200 to win his match. As we鈥檝e said, the implied probability here is 33.33%. So if we think that the player has a GREATER than 33.33% of winning, then it makes perfect sense to bet on him. If we think his chances are less than 33.33%, it鈥檚 wise not to bet on him.

If you鈥檇 like a more complete explanation on this subject, there鈥檚 an article in our sports betting guide that explains value and implied probability in further detail.

Odds Conversion Chart

The following chart shows the different formats for various commonly used odds.

Moneyline Decimal Fractional
-500 1.20 1/5
-400 1.25 1/4
-250 1.40 2/5
-200 1.50 1/2
-150 1.66 4/6
-125 1.80 4/5
-110 1.91 10/11
Moneyline Decimal Fractional
+100 2.00 1/1 or Evens
+110 2.10 11/10
+125 2.25 5/4
+150 2.50 6/4
+200 3.00 2/1
+250 3.50 5/2
+350 4.50 7/2

Odds Conversion Calculations

Since we鈥檝e provided this tool, you don鈥檛 need to know the calculations required to convert odds from one format to another. In the interests of completeness, however, we鈥檝e provided all of these calculations below. We鈥檝e included examples too.

Although you don鈥檛 NEED to know these, it won鈥檛 do you any harm to learn them. After all, there may be times when you need to convert odds but don鈥檛 have access to our conversion tool.

Moneyline format to decimal

There are two calculations for this. The first is used when converting positive moneyline odds. 鈥測鈥?is replaced by the relevant odds you want to convert.

(y + 100) / 100

Here鈥檚 an example, using +200 as the initial odds being converted.

(200 + 100) / 100 = 3

The second calculation is used when converting negative moneyline odds. Again, 鈥測鈥?is replaced by the relevant odds you want to convert. Please note that for the purposes of this calculation, the negative sign in the odds is ignored.

(y + 100) / y

Here鈥檚 an example, using -400 as the initial odds being converted.

(400 + 100) / 400 = 1.25

Moneyline format to fractional

The calculations for this conversion again depend on whether the moneyline odds are positive or negative. For positive moneyline odds, you create a fraction by placing the odds over 100. Then, if possible, you simplify the fraction. So, for +200, you鈥檇 create the fraction 200/100. This would be simplified to 2/1.

Negative moneylines work in the exact opposite way. So you create a fraction by placing 100 over the odds. The negative sign in the odds is ignored. So, for -400 you鈥檇 create the fraction 100/400. This would be simplified to 1/4.

Decimal format to moneyline

There are two calculations for this conversion too. The first is for when the decimal odds are greater than 2.00.

(y 鈥?1) x 100

You must add a positive sign to the result to get the correct moneyline odds. Here鈥檚 an example, using odds of 5.00.

(5 鈥?1) x 100 = 400

Add the positive sign, and we get +400.

Here鈥檚 the calculation required when the decimal odds are 2.00 or less.

100 / (y 鈥?1)

You must then add a negative size to get the correct moneyline odds. For this example, we鈥檒l use odds of 1.50.

100 / (1.50 – 1) = 200

Remember we need to add a negative sign this time. So the converted odds are -200.

Decimal format to fractional

Converting decimal odds to fractional format is a three step process. First you use the following calculation.

(y 鈥?1) x 100

Then you take the answer from that calculation and create a fraction by placing it over 100. In the third step, you simplify the fraction.

Let鈥檚 use 2.50 as an example. Here鈥檚 the first step.

(2.50 鈥?1) x 100 = 150

The second step then gives 150/100. For the third step, you simplify the fraction. 150/100 simplifies to 3/2.

Fractional format to moneyline

This is another conversion that requires two different calculations. The first is used when the odds are 鈥渙dds against鈥?(i.e. higher than evens).

(y) x 100

A positive sign must then be added to get the correct moneyline odds. For the example here, we鈥檒l use 3/1.

(3 / 1) x 100 = 300

Now add the positive sign and you get +300.

The second calculation is used when the odds are 鈥渙dds on鈥?(i.e. lower than evens).

100 / (y)

This time a negative sign must be added to get the correct moneyline odds. For this example, we鈥檒l use 1/2.

100 / (1 / 4) = 400

Now add the positive sign and you get -400.

Fractional format to decimal

We鈥檙e almost done. This is the last of the calculations for odds conversion. You鈥檒l be pleased to know it鈥檚 also very simple. Here it is.

(y) + 1

For this example, let鈥檚 use 5/2.

(5 / 2) + 1 = 3.50

That鈥檚 it! You now have all the tools you need to convert odds between any of the formats.