Types of odds: how odds are expressed in the various parts of the world

As we know, the odds determine how much one wins in a bet. These are, so to speak, applied to the wager to calculate the possible winnings.

Odds with the same value - that is, that result in the same identical payoff - can be presented in different ways. Some bookmakers offer multiple formats, providing simple conversion instruments.

Before moving on to the analysis, let's look at this comparison of the various odds that will be used in the examples below.

Decimal odds

Widely used in Europe - leading to them sometimes being called European or continental odds - when multiplied by the amount bet, they show the total paid by the bookmaker. Indeed, as is well known, the punter pays the bet in advance and then, if he wins, he collects on his earnings. European odds tell us how much will be paid out.

For example:
A bet of €1000 at 1.40 will result, if victorious, in a payment of €1400.
1,000 x 1.40 = 1,400
To calculate the profit, it is necessary to take the amount bet away from the payment.
1,400 - 1,000 = 400

Fractional odds

Commonly used in the UK and Ireland, odds in this format, multiplied by the bet, show the potential profit.

For example:
A bet of €1,000 at 2/5, will result, if victorious, in a profit of €400.
1,000 x 2/5 = 400
To calculate the payment, it is necessary to add the profit and amount bet together.
1,000 x (1+2/5) = 1,400

Fractional odds present a small problem when on tries to convert them into other formats.
The factions used are standardised.

Odds of 2/7 expressed in decimal format should be 1.2857, but a bet of €1000 at 2/7 often does not result in winnings of €285.70

The rounding off of the amount actually paid might be equal to €280 or €285.

American odds.

In contrast to what was noted before, American odds can be negative and positive. Interpreting the odds in this format thus varies depending on the sign.

The case of the winnings being less than the bet.

When a specific event - to use a simplification - has a less than 50% chance of happening, the potential winnings are less than the amount bet. This happens when the decimal odds are less than 2.00 and the fractional odds, 1/1 (normally expressed using the word "evens").

In American odds, the value of the odds indicates how much the bet must be to win 100 units. The - sign indicates in which of the two cases one is in and does not have a value in and of itself.

For example:
A bet of €1,000 at -250 will result, if victorious, in a profit of €400.
1,000 x 100/250 = 1,000 x 0.40 = 400
This is the formula for calculating the payment.
1,000 x (1+100/250) = 1,000 x (1+0.40) = 1,400

The case of the winnings being equal to or more than the bet.

In this case it is very simple, the odds indicate the winnings for every 100 units bet. To distinguish it from the case above, the + sign is placed in front of the odds.

For example:
A bet of €1,000 at +275 will result, if victorious, in a payment of €3,750.
1,000 x (1+275/100) = 1,000 x (1+2.75) = 3,750
To calculate the profit.
1,000 x 275/100 = 1,000 x 2.75 = 2,750

Malay odds

Once again, these odds have two "cases", although they are not quite the same as for the American system.

The case of the winnings being less than the bet.

In this case - and only to help us understand the situation we find ourselves in - the sign placed in front of the odds can help us. In this case, the sign used is + (in many cases, it is actually left out, so unless the sign is - , then it is definitely +).

For example:
A bet of €1,000 at +0.40 will result, if victorious, in a profit of €400.
1,000 x 0.40 = 400
This is the formula for calculating the payment.
1,000 x (1+0.40) = 1,000 x 1.40 = 1,400

The case of the winnings being equal to or more than the bet.

In this case, it is very simple: the odds indicate the amount that must be bet to win 1 unit.
The sign in front of odds is negative, but needs to be ignored when making the calculation.

For example:
A bet of €1,000 at 0.36 will result, if victorious, in a payment of €3,750.
1,000 x (1+1/0.36) = 1,000 x (1+2.77) = 3,777
To calculate the profit.
1,000 x (1/0.36) = 1,000 x 2.77 = 2,777

NB: in Malay odds, evens or 2.00 is expressed with 0.

The difference compared to the previous examples is due to the rounding off. In Malay odds, only two decimal points are used, while the exact conversion of 3.75 expressed in Malay format would be -0.3636. Here are the precise calculations.
1,000 x (1+1/0.3636) = 1,000 x 1+2.75 = 3,75
1,000 x (1/0.3636) = 1,000 x 2.75 = 2,750

Indonesian odds.

Indonesia odds are the same as American ones, but divided by 100.

The case of the winnings being less than the bet.

In this case, the odds indicate the value of a bet needed to win a single unit.

Clearly, the – sign is solely a convention.

For example:
A bet of €1,000 at -2.50 will result, if victorious, in a profit of €400.
1,000 x 1/2.50 = 1,000 x 0.40 = 400
This is the formula for calculating the payment.
1,000 x (1+1/2.50) = 1,000 x (1+0.40) = 1,400

The case of the winnings being equal to or more than the bet.
In this case it is very simple, the odds indicate the winning for each unit bet. To distinguish it from the case above, the + sign is placed in front of the odds.

For example:
A bet of €1,000 at +2.75 (or simply 2.75) will result, if victorious, in a payment of €3,750.
1,000 x (1+2.75) = 1,000 x 3.75) = 3,750
To calculate the profit.
1,000 x 2.75 = 2,750

Hong Kong odds
This is probably the simplest format and was also used in Italy prior to the introduction of the regulated market in 1998. For those who remember the old "Totonero betting forms", it is not unlike those. It worked a bit like fractional odds, where the odds simply indicated the net possible winnings.
For example:
A bet of €1,000 at 0.40 will result, if victorious, in a profit of €400.
1,000 x 0.40 = 400
or if the odds are 2.75
1,000 x 2.75 = 2.750

To calculate the payment, it is necessary to add the profit and amount bet together.
1,000 x (1+0.40) = 1,400
or if the odds are 2.75
1,000 x (1+2.75) = 3,750

Converting between the decimal and Hong Kong formats does not present any rounding off problems.

Some of the formulas to convert to and from decimal odds: