Want to convert between different odds formats?

Whether you’re Matched Betting, Arbing, Value Betting or Betfair Trading — you want the odds to be in decimal “European” format. In this post I’ll show you how to convert all other odds types into this format (and vice versa). You’ll also learn how to convert your decimal odds into an implied probability %.

**Fractional Odds**

It’s a traditional to use fractions in the UK and Ireland (e.g. 6/4, 1/3, 2/1). In all honestly I think they should be abolished. I don’t find it particularly easy to quantify the value of fractional odds, and the Bookies probably like it that way.

Importantly, unlike decimals odds, Fractional odds show us the possible *profit* (without the stake included).

### Calculating Profit: [Stake x Fraction]

**Fractional Odds of…**

- 2/1 = £200 profit on a £100 stake.
- 1/2 = £50 profit on a £100 stake.
- 1/1 = £100 profit on a £100 stake (“evens” or “even money”).

### Convert to Decimal: [Fraction + 1]

**Fractional Odds of…**

- 3/1 = 3.0 + 1 = 4.0 decimal odds
**.** - 1/2 = 0.5 + 1 = 1.5 decimal odds.
- 1/1 = 1 + 1 = 2.0 decimal odds.

To convert decimal odds to fractions: Decimal Odds - 1.0, and then find the nearest whole integers (e.g. 3.75 - 1 = 2.75/1, or 11/4).

**American Odds**

American odds are of course very popular at US bookmakers. They’re often called “money line” or “lines”. Importantly, the odds are different for underdogs and favourites. It’s represented in units of $100.

**If the odds are lower than evens (2.0 decimal)**, then American odds are negative and it shows how much money must be wagered to win $100.

**If the odds are higher than evens (2.0 decimal)**, then American odds are positive and it shows how much money will be won on a wager of $100.

### Calculating Profit (Favourites): [-100/Odds x Stake]

**American Odds of…**

- -200 = (-100/-200) = 1/2. Therefore, $50 profit on $100 staked.
- -400 = (-100/-400) = 1/4. Therefore, $25 profit on $100 staked.
- -500 = (-100/-500) = 1/5. Therefore, $10 profit on $50 staked.

### Calculating Profit (Underdogs): [Odds/100 x Stake]

**American Odds of…**

- 200 = (200/100) = 2/1. Therefore $200 profit on $100 staked.
- 300 = (300/100) = 3/1. Therefore $300 profit on $100 staked.
- 500 = (500/100) = 5/1. Therefore $250 profit on $50 staked.

### Convert to Decimal (Favourites): [-100/Odds + 1]

**American Odds of…**

- -500 = (-100/-500) +1 = 1/5 + 1 = 1.2 decimal odds.
- -400 = (-100/-400) + 1 = 1/4 + 1 = 1.25 decimal odds.
- -100 = (-100/-100) + 1 = 1 + 1 = 2.0 decimal odds.

### Convert to Decimal (Underdogs): [Odds/100 + 1]

**American Odds of…**

- 500 = (500/100) +1 = 5 + 1 = 6.0 decimal odds.
- 400 = (400/100) + 1 = 4 + 1 = 5.0 decimal odds.
- 200 = (200/100) + 1 = 3.0 decimal odds.

To convert Decimal odds of 2.00 or greater to American odds: (Decimal Odds – 1) x 100To convert Decimal odds of less than 2.00 to American odds: (-100)/(Decimal Odds -1)

**Hong Kong Odds**

Hong Kong odds are adopted by many Asian bookmakers. The odds are simple to work out, and are a cross between decimal and fractional odds. The profit calculation works just the same as fractional odds — only they’re presented in a decimal format.

### Calculating Profit: [Stake x odds]

**HK Odds of…**

- 2.0 = £200 profit on a £100 stake.
- 0.5 = £50 profit on a £100 stake.
- 3.0 = £150 profit on a £50 stake.

### Convert to Decimal: [Odds + 1]

**HK Odds of…**

- 0.4 = 0.4 + 1 = 1.4 decimal odds.
- 5.0 = 5.0 + 1 = 6.0 decimal odds.
- 1.5 = 1.5 + 1 = 6.5 decimal odds.

To convert decimal odds to Hong Kong odds:(Decimal Odds -1)

**Indonesian Odds**

These are like US odds — except instead of $100 it’s in terms of $1. So when it’s a negative value, it shows how big the wager is needed for a profit of $1. And when it’s positive, it shows the profit from a wager of 1.

### Calculating Profit (Favourites): [-1/Odds x Stake]

**Indonesian Odds of…**

- -2.0 = (-1/-2) = 0.5. Therefore, $0.5 profit on $1 staked.
- -1.25 = (-1/-1.25) = 0.8. Therefore, $80 profit on $100 staked.
- -1.5 = (-1/-1.5) = 2/3. Therefore, $40 profit on $60 staked.

### Calculating Profit (Underdogs): [Odds x Stake]

**Indonesian Odds of…**

- 4.0 = $400 profit on $100 staked.
- 3.0 = $300 profit on $100 staked.
- 5.0 = $250 profit on $50 staked.

### Convert to Decimal (Favourites): [-1/Odds + 1]

**Indonesian Odds of…**

- -5.0 = (-1/-5) +1 = 1/5 + 1 = 1.2 decimal odds.
- -4.0 = (-1/-4) + 1 = 1/4 + 1 = 1.25 decimal odds.
- -1 = (-1/-1) + 1 = 1 + 1 = 2.0 decimal odds.

### Convert to Decimal (Underdogs): [Odds + 1]

**Indonesian Odds of…**

- 5.0 = 5 +1 = 6.0 decimal odds.
- 4.0 = 4 + 1 = 5.0 decimal odds.
- 2.0 = 2 + 1 = 3.0 decimal odds.

To convert Decimal odds of 2.00 or greater to Indonesian odds: (Decimal Odds – 1)To convert Decimal odds of less than 2.00 to Indonesian odds: (-1)/(Decimal Odds -1)

**Malaysian Odds**

Malaysian odds are the opposite of the US and Indonesian format.

### Calculating Profit (Favourites): [Odds x Stake]

**Malaysian Odds of…**

- 5.0 = $500 from on $100 staked.
- 4.0 = $400 profit on $100 staked.
- 1.0 = $50 profit on $50 staked.

### Calculating Profit (Favourites): [-1/Odds x Stake]

**Malaysian Odds of…**

- -2.0 = (-1/-2) = 0.5. Therefore, $0.5 profit on $1 staked.
- -1.25 = (-1/-1.25) = 0.8. Therefore, $80 profit on $100 staked.
- -1.5 = (-1/-1.5) = 2/3. Therefore, $40 profit on $60 staked.

### Convert to Decimal (Positive): [Odds + 1]

**Malaysian Odds of…**

- 5.0 = 6.0 decimal odds.
- 4.0 = 5.0 decimal odds.
- 1.0 = 2.0 decimal odds.

### Convert to Decimal (Negative): [-1/odds +1]

**Malaysian Odds of…**

- -5.0 = -1/-5 + 1 = 1.2 decimal odds.
- -4.0 = -1/-4 + 1 = 1.25 decimal odds.
- -0.6 = -1/-0.6 + 1 = 2.67 decimal odds.

To convert Decimal odds of 2.00 or less to Malay odds: (Decimal Odds – 1)To convert Decimal odds of greater than 2.00 to Malay odds: (-1)/(Decimal Odds -1)

## The Probability (Implied Odds)

Probabilities aren’t used by Bookmakers or the betting exchanges — but it’s good to know how to translate odds into the implied chance (%). The implied chance value tells us the % chance, according the odds, of an event happening.

### Convert From Decimal: [1 / Decimal Odds]

**Decimal Odds of…**

- 5.0 = (1/5) = 0.2 = 20% chance
- 2.0 = (1/2) = 0.5 = 50 % chance
- 1.5 = (1/1.5) = 2/3 = 66.67% chance

### Convert To Decimal : [100/Chance %]

**Implied Chance of…**

- 40% chance = 100/40 = 2.5 decimal odds
- 90% chance = 100/90 = 1.11 decimal odds
- 25% chance = 100/25 = 4.0 decimal odds

#### Further Reading:

How Do Bookmakers Earn? How Big Is Their Edge?

Sports Spread Betting Explained + Fixed Odds Comparison

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