American odds

American odds, also refered to as moneyline odds, are the odds favoured by American bookmakers. The odds are quoted as either positive or negative and are accompanied with a plus or minus symbol to show the favourite and the underdog.

How to read American odds

Positive odds represent the underdog in a bet, meaning this outcome is considered less likely to happen than not. The positive odds indicate how much money would be won from a $100 bet.

For example, if odds of +300 were quoted, then a $100 bet would see returns of $300 and a total payout of $400.

Negative odds represent the favourite in a bet, meaning this outcome is considered more likely to happen than not. The negative odds represent how much money must be bet to see returns of $100.

For example, if odds of -300 were quoted, then a $300 bet would see returns of $100 and a total payout of $400.

Odds of +100 are also referred to as evens, meaning the bookmaker is suggesting that the chance of the outcome occurring is 50/50.

Calculating returns using American odds

It is relatively straight forward to calculate returns using American odds if you are placing a $100 bet - but often this is not the exact figure of our stake.

Calculating returns with positive odds

To calculate returns on a positive odds bet, the following formula is used:

Stake * (odds / 100)

For example

  • Arsenal vs Chelsea - Arsenal to win odds of +250 with a $10 bet stake

10 * (250 / 100) = 25

Therefore returns would be $25.

Calculating returns with negative odds

To calculate returns on a negative odds bet, the following formula is used:

Stake * ((100 / (odds * - 1))

For example

  • Liverpool vs Everton - Liverpool to win at odds of -400 with a $10 stake

10* ((100 / (-400 * -1)) = 2.5

Therefore returns would be $2.50.

Converting American odds into decimal odds

In order to convert American odds into decimal odds, the following formulas are used.

For positive odds, the formula for converting American odds into decimal odds is as follows:

Odds / 100 + 1

For example

  • Atalanta vs Roma - over 2.5 goals at odds of +150

150 / 100 + 1 = 2.50

For negative odds, the formula for converting American odds into decimal odds is as follows:

100 / Odds + 1

For example

  • Inter Milan vs AC Milan - Inter to win at odds of -250

100 / 250 + 1 = 1.40

Converting decimal odds into American odds

To convert decimal odds of over 2.00 into American odds, the following formula is used:

(Decimal - 1) * 100

For example

(3.35 - 1) * 100 = +235

To convert decimal odds of under 2.00 into American odds, the following formula is used:

-100 / (decimal - 1)

For example

  • Roma vs Atalanta - Roma to win at odds of 1.65

-100 / (1.65 - 1) = -154

Converting American odds into fractional odds

In order to convert American odds into fractional odds, the odds are arranged in a certain way and then reduced to their simplest form.

For positive odds, to convert American odds into fractional odds, the odds are arranged as follows:

Odds/100

And then reduced into simplest form.

For example

  • Barcelona vs Real Madrid - Real Madrid to win at odds of +300

300/100 reduces down into 3/1

For negative odds, to convert American odds into fractional odds, the odds are arranged as follows:

100/odds

And then reduced into simplest form.

For example

  • Atletico Madrid vs Valencia - Atletico Madrid to win at odds of -250

100/250 reduces down to 2/5

Converting fractional odds into American odds

Fractional odds above 1/1 will provide positive American odds. To convert fractional odds of above 1/1 into American odds, the following formula is used:

(numerator / denominator) *100

For example

(7 / 4) * 100 = +175

Fractional odds of under 1/1 will provide negative American odds. To convert fractional odds under 1/1 into American odds, the following formula is used:

-100 / (numerator / denominator)

For example

  • Juventus vs Roma - Juventus to win at odds of 1/4

-100 / (1 / 4) = -400

Converting American odds into implied probability

Implied probability is the conversion of odds into a percentage to show the expected probability of an outcome.

The formula for converting positive American odds into implied probability is as follows:

100 / (odds + 100) * 100 = implied probability

For example

  • Chelsea to beat Manchester United at odds of +200

100 / (200 + 100) * 100 = 33.3%

The formula for converting negative American odds into implied probability is as follows:

Negative American odds / (odds + 100) * 100 = implied probability

For example

  • Manchester United vs Chelsea - Manchester United to win at odds of -200

200 / (200 + 100) * 100 = 66.7%

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