Understanding betting odds is essential if you want to make informed decisions when placing wagers. While UK bettors are most familiar with fractional odds and many European sportsbooks use decimal odds, American odds are widely used across major sportsbooks, particularly in the United States.
In this guide for BonusReferrerCode.com, we break down how American odds work, how to convert them into decimal and fractional formats, how to calculate potential returns, and where you are most likely to encounter each odds format. By the end, you will know exactly how to read American odds and which format is the simplest for calculations, especially if you are not using a bet calculator.
American odds, also known as moneyline odds, are expressed using either a plus (+) or minus (−) sign in front of a number. They show how much you can win relative to a standard stake of $100.
There are two types of American odds:
Unlike decimal odds, American odds do not immediately show your total return including stake. Instead, they are based around the benchmark figure of 100.
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Positive American odds show how much profit you would make from a $100 stake.
For example:
Formula to convert positive American odds to decimal:
Decimal = (American Odds ÷ 100) + 1
So for +200:
(200 ÷ 100) + 1 = 3.00
Fractional conversion:
American Odds ÷ 100
200 ÷ 100 = 2/1
Positive American odds are typically seen on underdogs or longer-priced selections.
Negative American odds show how much you need to stake in order to win $100 profit.
For example:
Formula to convert negative American odds to decimal:
Decimal = (100 ÷ American Odds) + 1
Note: Use the absolute number, ignoring the minus sign.
For −150:
(100 ÷ 150) + 1 = 1.67
Negative American odds are used for favourites.
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Here is a comparison table to help visualise equivalent formats:
| American | Decimal | Fractional |
|---|---|---|
| +100 | 2.00 | 1/1 |
| +200 | 3.00 | 2/1 |
| +300 | 4.00 | 3/1 |
| −110 | 1.91 | 10/11 |
| −150 | 1.67 | 2/3 |
| −200 | 1.50 | 1/2 |
Each format represents the same implied probability, but displayed differently.
If you are unsure how to calculate potential returns using American odds, a Bet Calculator makes the process simple.
Choose the amount you wish to wager.
Input either the positive (+) or negative (−) odds value.
The calculator automatically converts the odds and shows:
For example:
Stake: $50
Odds: +200
Profit = $100
Total Return = $150
For negative odds:
Stake: $50
Odds: −150
Profit = $33.33
Total Return = $83.33
Bet calculators remove manual errors and are particularly helpful when working with multiple selections or accumulator bets.
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If you are betting in the UK, you will most frequently encounter fractional and decimal odds, bet365 uses both these options. However, many online bookmakers allow you to switch formats in your account settings.
For pure calculations, decimal odds are generally the easiest to use.
With decimal odds:
Total Return = Stake × Decimal Odds
For example:
£20 at 2.50
£20 × 2.50 = £50 return
This simplicity makes decimal odds the preferred format for many experienced bettors. American odds require an additional step of calculation, particularly when dealing with negative numbers.
However, American odds are intuitive once understood because they clearly show whether a selection is favourite or underdog based on the plus or minus symbol.
With sports betting becoming increasingly global, you may encounter American odds when:
Knowing how to convert American odds into decimal or fractional formats allows you to quickly assess value and compare markets effectively.
+100 means you win $100 profit from a $100 stake. It is equivalent to 2.00 decimal or 1/1 fractional.
−110 means you must stake $110 to win $100 profit. It converts to approximately 1.91 in decimal format.
No format is better in value terms. They represent the same probabilities. Decimal odds are generally simpler for calculations.
Negative odds indicate how much you need to stake to win $100 profit. Favourites are more likely to win, so the return per unit staked is lower.
Most modern online bookmakers allow users to switch between American, decimal and fractional formats in account settings.
Convert them to decimal format and compare the implied probability to your own assessment of the event’s likelihood.
Understanding how to read American odds is an essential skill for any serious sports bettor. While they may initially seem confusing compared to decimal or fractional formats, they follow a clear structure based around a $100 reference point.
For simplicity in calculations, decimal odds remain the easiest option. However, with the global nature of sports betting, being comfortable with American odds ensures you can interpret prices accurately wherever you place your bets.
Using a bet calculator can help you translate the value of a bet in any odds format.
Keep learning, compare markets carefully, and always check your chosen bookmaker for the latest odds before placing a wager.
18+ Always remember to gamble responsibly. Check out bet365’s Safer Gambling page for more details or go to GambleAware.org for advice, tools and support.
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