May 17, 2021

How to Convert Betting Odds and Calculate Betting Profits Without Using Technology

Understanding different odds formats, what they mean, and how much money your bets will win if they are successful is pretty easy when you use online tools to help you out.

However, when you want to quickly judge whether a bet is worth it or not, sometimes it’s more effective to know exactly how to calculate these things yourself.

What is more, three different types of odds are commonly used at betting websites worldwide, which means that even if you understand decimal odds, you may encounter fractional or American odds in the future and not have a clue what they mean.

With this in mind, we’ll examine Decimal, Fractional, and American odds formats, how you can convert these odds into each other and how you can calculate your profits for each odds type.

Where do you find different odds types?

Decimal odds are most commonly used in Europe, except for in the UK and Ireland where fractional odds tend to be the most common. In the USA, Canada, and Latin America, American odds, or Moneyline odds are the most common.

In countries like New Zealand, many aspects of betting culture are borrowed from a variety of other places around the world. That means that on New Zealand betting sites you’ll see a variety of different odds formats, although there will usually also be an option to change your odds type to your most preferred format.

What do odds tell us?

Odds represent the likelihood of an outcome happening. Betting odds also tell you how much your bet stake will be multiplied by if you place a bet at these odds.

In this way, the higher the odds are, the less likely something is to happen and the more money you will win if you place a successful bet at these odds.

It’s also interesting to note that the odds displayed on betting sites never represent the true likelihood of an outcome happening. That’s because bookmakers must factor in a margin to their odds so that they always have an edge over bettors.

Calculating Profits from Decimal Odds

Decimal odds are displayed as numbers with decimal places.

For example, let’s say that Manchester United is playing against Chelsea FC in the English Premier League.

The odds are given as follows:

• Manchester United to Win: 2.50
• Draw: 3.40
• Chelsea FC to Win: 2.80

For decimal odds, your winnings can be calculated by multiplying your bet stake (the amount you bet), by the decimal odds of this outcome.

Winnings = Bet Stake x Decimal Odds

Therefore a \$10 bet on Manchester United would return \$25.

Winnings = \$10 x 2.50 = \$25

Your profits can then be calculated by subtracting your initial bet stake

Profit = \$25 – \$10 = \$15

In the same way, a correct bet on the draw would return \$34 and a correct bet on Chelsea FC would return \$28 for \$24 and \$18 in profit respectively.

Calculating Profits from Fractional Odds

As you can probably guess, fractional odds are displayed as fractions.

Fractional odds are specifically designed to tell you exactly what your profits will be and exactly what the implied probability of an outcome occurring is.

Overall, they are pretty similar to decimal odds.

If we continue with the example used above, the same odds for the Manchester United vs Chelsea FC match expressed as fractions are:

• Manchester United to Win: 3/2
• Draw: 12/5
• Chelsea FC to Win: 9/5

For fractional odds, your profits can be calculated easily by multiplying your bet stake by the fractional odds of your bet.

Profit = Bet Stake x Fractional Odds

For the Manchester United Win bet:

Profit = \$10 x 3/2 = \$15

Winnings = \$15 + \$10 = \$25

To get the implied probability of your bet occurring i.e. how likely the bookmaker thinks the bet is (with their margin taken into account) simply divide the bottom number in the fraction by the sum of both the bottom and top number in the fraction.

For example, the implied probability of Manchester United winning is 40%:

2 ÷ (3 + 2) = 2/5 = 40%

Calculating Profits from American Odds (Moneyline)

American odds or Moneyline odds are a bit different.

American odds can be displayed as positive or negative numbers. A ‘-’ sign will precede negative numbers while positive numbers may have a ‘+’ or it may be implied that the odds are positive.

For the Manchester United vs Chelsea FC match, the American odds are:

• Manchester United to Win: +150
• Draw: +240
• Chelsea FC to Win: +180

American odds are designed to tell you what your winnings will be based on \$100 bets.

• Positive American Odds tell you how much money you will win on a \$100 bet. Eg. if you bet \$100 on Manchester United to win you can expect to win \$150
• Negative American Odds tell you how much money you have to bet to win \$100. Eg. if you bet \$125 at odds of -125 you would win \$100

How to calculate your profits from American odds bets depends on whether the odds are a positive or negative number:

• For Positive American Odds multiply your bet stake by your odds over 100

Profits = Bet Stake x Odds/100

For the Manchester United Win bet:

Profits = \$10 x 150/100 = \$15

• For Negative American Odds divide your bet stake by your odds over -100

Profits = Bet Stake ÷ Odds/-100

For a \$10 bet at odds of -125:

Profits = \$10 ÷ -125/-100 = \$8.00

Winnings = \$8 + \$10 = \$18

How to Convert Decimal Odds to Fractions and American Odds

Converting between decimal, fractional and American odds is easy as long as you know how to.

Convert Decimal Odds to Fractional Odds

Subtract your decimal odds by 1 and then convert to a fraction to get the fractional odds. To convert 2.50 to fractional odds:

2.50 – 1 = 1.50 = 3/2

Convert Decimal Odds to American Odds

If your decimal odds are 2.00 or larger, subtract your decimal odds by 1 and then multiply the result by 100. To convert 2.50 to American odds:

(2.50 – 1) x 100 = 1.50 x 100 = +150

If your decimal odds are smaller than 2.00, take -100 and then divide it by your decimal odds minus 1. To convert 1.80 to American odds:

-100 ÷ (1.80 – 1) = -100/0.80 = -125

Convert Fractional Odds to Decimal Odds

Convert your fractional odds to decimal and then add 1. To convert 3/2 to decimal odds:

3/2 + 1 = 1.50 + 1 = 2.50

Convert Fractional Odds to American Odds

If your fractional odds are larger than 1/1, multiply your fractional odds by 100 and then convert your answer to a whole number. To convert 3/2 to American odds:

3/2 x 100 = 300/2 = +150

If your fractional odds are smaller than 1/1, take -100 and divide it by your fractional odds and then convert your answer to a whole number. To convert 4/5 to American odds:

-100 ÷ (4/5) = -500/4 = -125

Convert American Odds to Decimal Odds

If your American odds are positive, divide the American odds by 100, convert this number to a decimal and then add 1. To convert +150 to decimal odds:

150/100 + 1 = 3/2 + 1 = 1.50 + 1 = 2.50

If your American odds are negative, divide 100 by the American odds, convert this number to a decimal and then take 1 and minus it from your answer. To convert -125 to decimal odds:

1 – (100/-125) = 1 – (4/-5) = 1 – -0.80 = 1.80

Convert American Odds to Fractional Odds

If your American odds are positive, divide the American odds by 100. To convert +150 to fractional odds:

150/100 = 3/2

If your American odds are negative, divide -100 by the American odds. To convert -125 to fractional odds:

-100/-125 = 4/5