How To Convert Odds

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How do you convert odds into their implied probabilities? And how do you convert implied probability into the range of popular odds formats? Use our odds conversion calculator or learn the formulas behind.

 

Knowing how to convert betting odds can be very helpful. In fact, if you don't know how to convert betting odds into their respective implied probabilities, you're not helping your chances of coming away as a long term winner in the competitive world of sports betting. Understanding the implied probability behind the odds on offer is key to assessing the potential value in a particular betting market. And it is just as important when assessing the value that exists with regards to specific odds on a particular outcome. If the implied probability is less than your own assessed probability of a particular outcome occurring, that outcome represents a value betting opportunity.

Converting Odds To Implied Probability

Typically, there are three kinds of odds you will come across in the sports betting landscape.

  • Decimal odds: represented as 1.65 or 2.95 etc.
  • Fractional odds: represented as 5/2 or 3 to 2 'on' etc.
  • Moneyline odds: represented as -120 or +140 etc.

They all reflect the same thing, the return you will receive on a given amount of money placed on a bet. To convert your odds to implied probabilities or an implied probability to odds, you can either use our odds conversion calculator or do it by hand with the formulas provided below the calculator.

Odds Conversion Calculator

Converting Decimal Odds

Decimal odds are a simple reflection of the return you will receive for each single unit placed. For example, let's say bookmaker Matchbook is offering odds of 1.65 for Manchester United to win. This means that for every 1.00 you bet on that particular outcome, you will receive a profit of 0.65 should Manchester United win.

To convert these odds to their respective implied probabilities we make a simple calculation.

Converting decimal odds to implied probability formula:

Implied probability = 1 / decimal odds

Let's look at an example, in which Diego Costa to get a yellow card is odds 1.65.

Example: How to convert decimal odds to its implied probability

1 / 1.65 = 0.606 = 60.6%

Multiplied then by 100 to express as an implied probability percentage of 60.6%.

Converting Fractional odds

Fractional odds are generally the most traditional form of expressing betting odds. They are a simple reflection of the return you will receive for a particular amount bet.

So for example, let's say bookmaker Ladbrokes is offering odds of 5/2 for a particular horse to win an upcoming race. The odds of 5/2 (expressed as "5 to 2") means that for every 2 units that you bet, you will receive 5 back as profit. So if you bet €200 on that horse, you would have received €500 profit in return plus your original stake of €200.

Converting fractional odds into implied probability formula:

Implied probability = denominator / (denominator + numerator)

Let's look at an example, in which Diego Costa to get a yellow card is odds 5/2.

Example: How to convert fractional odds to its implied probability

5 / 2 = 2 / (2 + 5) = 2 / 7 = 0.2857 = 28.57%

Multiplied then by 100 to express as a implied probability percentage of 28.57%

Converting Moneyline Odds

Moneyline odds, also known as 'American odds' are probably the most foreign odds format to those of us outside of North America. And at first they appear a little confusing. But it is helpful to understand what these odds represent especially when listening to Americans speaking about gambling odds in sports broadcasts or podcasts. So, let's see how we can convert Moneyline odds into their respective implied probabilities.

There are two instances of Moneyline odds: 'minus' moneylines and 'plus' moneylines.

The first are 'minus' moneylines. This is expressed as for example, -120. But what does this mean exactly? Well, let's say bookmaker bet365 are offering odds of -120 for the Los Angeles Lakers to win a game. This is essentially saying that to win $100 you have to bet $120. In other words, if you place $120 on that outcome, you will receive a profit of $100.

The other instance are 'plus' moneylines. This is expressed as for example +180. In this case, let's say bookmaker Winner Sports have offered odds of +180 for the New York Yankees to win a game. This simply means that if you bet $100, you will win $180.

So how do we convert the the 'minus' and the 'plus' moneyline odds into their implied probabilities? Let's start out with the 'minus' moneyline conversion:

Converting 'minus' moneyline odds into implied probability formula:

Implied probability = ( - ( 'minus' moneyline odds ) ) / ( - ( 'minus' moneyline odds ) ) + 100

So let's take an example, in which Titanbet offers the following bet: San Diego Chargers to win against New England Patriots at odds -120.

Example: How to convert 'minus' moneyline odds to its implied probability

(- (-120) / ( (- (-120) ) + 100) = 120 / 220 = 0.545 = 54.5%

Multiplied then by 100, we get the implied probability percentage of 54.5%.

Converting a 'plus' moneyline is a bit different. Calculating the implied probabilities on these look like this:

Converting 'plus' moneyline odds into implied probability formula:

Implied probability = 100 / ( 'plus' moneyline odds + 100 )

So let's take an example, in which Paddy Power offers odds +180 for Los Angeles Lakers to beat Miami Heat.

Example: How to convert 'plus' moneyline odds to its implied probability

( 100 / 180 + 100 ) = 100 / 280 = 0.357 = 35.7%

Multiplied then by 100, we get the implied probability percentage of 35.7%.

How Do We Convert Implied Probability Into Odds?

Knowing how to convert one form of odds to another can be helpful, especially if you have come into possession of a large amount of betting data that has odds formatted in an unfamiliar way.

To do this, we first need to convert any odds format to their implied probability. Once we have done this, the calculations are fairly straight forward.

Converting Implied Probability Into Decimal Odds

Converting implied probability into decimal odds formula:

Decimal odds = 100 / implied probability

Let's take an example. In this example we think that Arsenal has a 75 % probability of defeating Stoke. To calcluate our decimal odds target, we want to covert 75 % into odds:

Example: How to calculate implied probability to decimal odds:

100 / 75 = 1.33

Implied probability of 75% would return decimal odds of 1.33.

Converting Implied Probability Into Fractional Odds

Convert implied probability into fractional odds formula:

Fractional odds = ( 100 / implied probability ) -1

Let's look at an example, where we think Wayne Rooney has 25% probability of scoring a goal. In this example, the fractional odds target will be calculated as:

Example: How to convert implied probability to fractional odds:

(100 / 25) - 1 = 4 - 1 = 3

The outcome of this formula is 3, meaning we will express the odds as fractional odds = 3 to 1.

Converting Implied Probability Into Moneyline Odds

Converting implied probability into moneyline is a bit more complicated than converting it into decimal or fractional odds. The calculation depends on whether the implied probability is above 50% or below.

When the implied probability is above 50%, we make the following calculation.

Convert implied probability (50% and above) into moneyline odds formula:

Moneyline Odds = - ( implied probability / (100 - implied probability)) x 100

Let's look at an example, where we think Lionel Messi has a 75 % chance of scoring against Levante. In this example, the moneyline odds target will be calculated as:

Example: How to convert implied probability (50% and higher) to moneyline odds:

- (75 / (100 – 75)) x100 = - (75 / 25) x 100 = - 3 x 100 = - 300

Moneyline odds = - 300.

When the implied probability is below 50%, the calculation is adjusted a little.

Convert implied probability (below 50%) into moneyline odds formula:

Moneyline odds = (100 - implied probability / implied probability ) x 100

Let's look at an example, where we think Niclas Bendtner has a 25 % chance of scoring against VfB Stuttgart. In this example, the moneyline odds target will be calculated as:

Example: How to convert implied probability (below 50%) to moneyline odds:

((100 - probability)/(probability) x 100) = ((75) / (25) x 100) = 3 x 100 = 300

Moneyline odds = + 300.

Odds Conversion Chart

As a quick comparison guide, we've created an odds conversion chart which displays the odds and implied probability across each odds format.

Implied Probability %Decimal OddsFractional OddsAmerican Odds
99.0 1.01 1/100 -10000
98.0 1.02 1/50 -5000
97.1 1.03 1/33 -3333
96.2 1.04 1/25 -2500
95.2 1.05 1/20 -2000
94.3 1.06 3/50 -1667
93.5 1.07 7/100 -1429
92.6 1.08 2/25 -1250
91.7 1.09 9/100 -1111
90.9 1.10 1/10 -1000
90.1 1.11 11/100 -909
89.3 1.12 3/25 -833
88.5 1.13 13/100 -769
87.7 1.14 7/50 -714
87.0 1.15 3/20 -667
86.2 1.16 4/25 -625
85.5 1.17 17/100 -588
84.7 1.18 9/50 -556
84.0 1.19 19/100 -526
83.3 1.20 1/5 -500
82.6 1.21 21/100 -476
82.0 1.22 11/50 -455
81.3 1.23 23/100 -435
80.6 1.24 6/25 -417
80.0 1.25 1/4 -400
79.4 1.26 13/50 -385
78.7 1.27 27/100 -370
78.1 1.28 7/25 -357
77.5 1.29 29/100 -345
76.9 1.30 3/10 -333
76.3 1.31 31/100 -323
75.8 1.32 8/25 -313
75.2 1.33 33/100 -303
74.6 1.34 17/50 -294
74.1 1.35 7/20 -286
73.5 1.36 9/25 -278
73.0 1.37 37/100 -270
72.5 1.38 19/50 -263
71.9 1.39 39/100 -256
71.4 1.40 2/5 -250
70.9 1.41 41/100 -244
70.4 1.42 21/50 -238
69.9 1.43 43/100 -233
69.4 1.44 11/25 -227
69.0 1.45 9/20 -222
68.5 1.46 23/50 -217
68.0 1.47 47/100 -213
67.6 1.48 12/25 -208
67.1 1.49 49/100 -204
66.7 1.50 1/2 -200
65.8 1.52 13/25 -192
64.9 1.54 27/50 -185
64.1 1.56 14/25 -179
63.3 1.58 29/50 -172
62.5 1.60 3/5 -167
61.7 1.62 31/50 -161
61.0 1.64 16/25 -156
60.2 1.66 33/50 -152
59.5 1.68 17/25 -147
58.8 1.70 7/10 -143
58.1 1.72 18/25 -139
57.5 1.74 37/50 -135
56.8 1.76 19/25 -132
56.2 1.78 39/50 -128
55.6 1.80 4/5 -125
54.9 1.82 41/50 -122
54.3 1.84 21/25 -119
53.8 1.86 43/50 -116
53.2 1.88 22/25 -114
52.6 1.90 9/10 -111
52.1 1.92 23/25 -109
51.5 1.94 47/50 -106
51.0 1.96 24/25 -104
50.5 1.98 49/50 -102
50.0 2.00 1/1 100
49.5 2.02 51/50 102
49.0 2.04 26/25 104
48.5 2.06 53/50 106
48.1 2.08 27/25 108
47.6 2.10 11/10 110
46.5 2.15 23/20 115
45.5 2.20 6/5 120
44.4 2.25 5/4 125
43.5 2.30 13/10 130
42.6 2.35 27/20 135
41.7 2.40 14/10 140
40.8 2.45 29/20 145
40.0 2.50 3/2 150
38.5 2.60 8/5 160
37.0 2.70 17/10 170
35.7 2.80 9/5 180
34.5 2.90 19/10 190
33.3 3.00 2/1 200
31.3 3.20 11/5 220
29.4 3.40 12/5 240
27.8 3.60 13/5 260
26.3 3.80 14/5 280
25.0 4.00 3/1 300
23.8 4.20 16/5 320
22.7 4.40 17/5 340
21.7 4.60 18/5 360
20.8 4.80 19/5 380
20.0 5.00 4/1 400
19.2 5.20 21/5 420
18.5 5.40 22/5 440
17.9 5.60 23/5 460
17.2 5.80 24/5 480
16.7 6.00 5/1 500
16.1 6.20 26/5 520
15.6 6.40 27/5 540
15.2 6.60 28/5 560
14.7 6.80 29/5 580
14.3 7.00 6/1 600
13.3 7.50 13/2 650
12.5 8.00 7/1 700
11.1 9.00 8/1 800
10.0 10.00 9/1 900
9.1 11.00 10/1 1000
8.3 12.00 11/1 1100
7.7 13.00 12/1 1200
7.1 14.00 13/1 1300
6.7 15.00 14/1 1400
5.0 20.00 19/1 1900
3.3 30.00 29/1 2900
2.5 40.00 39/1 3900
2.0 50.00 49/1 4900
1.0 100.00 99/1 9900
0.7 150.00 149/1 14900
0.5 200.00 199/1 19900

 

Bookmaker Odds Settings

Most online bookmakers now offer alternative display options for their odds. Below you can see the odds options available at bet365. Simply check your preferred odds format and all odds in all markets offered by bet365 will appear in that format.

bet365 sign up bonus

 

So let's sum it up.........

How To Convert Odds

Converting fractional odds to decimal we add the numerator to the denominator and divide the total by the denominator e.g 9/2 becomes 11/2 which equals decimal odds of 5.50. Then to convert decimal odds to their probabilities divide 1 by the decimal odds. e.g odds of 4.00, 1 divided by 4.00 equals a probability of 25%.

While there are many tools on the web that will help you convert odds to their implied probabilities and convert odds to other formats, it is still a good practise to understand the calculations behind these conversions. This will only help you better understand what the odds represent in terms of value as well as exercising your betting brain to think instinctively in terms of implied probabilities when odds are presented to you.


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