Decimal vs American Odds: How Betting Odds Work and Convert
Learn the difference between decimal and American betting odds, how to convert between formats, calculate payouts and read implied probability.
Decimal and American odds describe the same betting prices in different formats. Decimal odds are commonly used outside the United States, while American odds—also called moneyline odds—are standard in the US. Knowing how to convert between them helps you compare sportsbooks, understand potential returns and assess the probability implied by a price.
What is the difference between decimal and American odds?
Decimal odds show the total return for every unit staked, including the original stake. For example, decimal odds of 2.50 return $25 from a $10 bet: $25 total, made up of a $15 profit and the $10 stake.
American odds use positive and negative numbers. Positive odds show how much profit a $100 stake would make. Negative odds show how much you must stake to make $100 profit.
- +150: A $100 stake produces $150 profit and returns $250 in total.
- -150: You need to stake $150 to make $100 profit, receiving $250 in total if the bet wins.
Decimal odds are usually easier for comparing total returns, while American odds quickly indicate which side is the favorite and which side is the underdog.
How to convert decimal odds to American odds
The conversion depends on whether the decimal price is above or below 2.00. A decimal price of 2.00 represents even odds, equivalent to American odds of +100.
- Decimal odds of 2.00 or higher:
(decimal odds - 1) × 100 - Decimal odds below 2.00:
-100 ÷ (decimal odds - 1)
For example, decimal odds of 2.50 convert as follows: (2.50 – 1) × 100 = +150.
For decimal odds of 1.67, the calculation is -100 ÷ (1.67 – 1), which is approximately -149. Sportsbooks may display this as -150 after rounding.
How to convert American odds to decimal odds
Use one formula for positive American odds and another for negative odds:
- Positive odds:
1 + (American odds ÷ 100) - Negative odds:
1 + (100 ÷ absolute value of American odds)
For +200, the calculation is 1 + (200 ÷ 100) = 3.00 decimal odds.
For -125, the calculation is 1 + (100 ÷ 125) = 1.80 decimal odds.
The absolute value is used for negative prices, so -125 is treated as 125 in the calculation.
Decimal and American odds conversion table
| Decimal odds | American odds | Implied probability |
|---|---|---|
| 1.25 | -400 | 80.00% |
| 1.50 | -200 | 66.67% |
| 1.67 | Approximately -150 | 59.88% |
| 2.00 | +100 | 50.00% |
| 2.50 | +150 | 40.00% |
| 3.00 | +200 | 33.33% |
| 4.00 | +300 | 25.00% |
Small differences can occur because sportsbooks round displayed prices. A conversion calculator may therefore show a slightly different American number from the one listed by a bookmaker.
How to calculate betting payouts
With decimal odds, multiply the stake by the decimal price:
total return = stake × decimal odds
A $20 bet at 2.40 returns $48, including $28 profit. The profit calculation is:
profit = stake × (decimal odds - 1)
With American odds, positive prices use:
profit = stake × (American odds ÷ 100)
A $20 bet at +150 earns $30 profit and returns $50 in total.
For negative American odds, use:
profit = stake × (100 ÷ absolute value of American odds)
A $20 bet at -150 earns approximately $13.33 profit and returns approximately $33.33 in total.
How implied probability works
Odds can be converted into an implied probability, which is the percentage suggested by the price before accounting for the sportsbook’s margin.
- Decimal odds:
1 ÷ decimal odds × 100 - Positive American odds:
100 ÷ (American odds + 100) × 100 - Negative American odds:
absolute value of American odds ÷ (absolute value of American odds + 100) × 100
Decimal odds of 2.50 imply a probability of 40%. American odds of -150 imply a probability of 60%. This is not necessarily the true chance of an outcome because the sportsbook builds a margin, often called the vig, over the market.
Which odds format is easier to use?
Decimal odds are often the most straightforward format for calculating a complete return and comparing prices across international sportsbooks. Every increase in the decimal number directly changes the total payout per unit staked.
American odds are useful for identifying market favorites. Negative numbers indicate the side expected to win more often, while positive numbers indicate an underdog. However, the size of a negative number can be less intuitive until you are familiar with the required stake and profit.
Regardless of format, compare the same market, outcome and settlement rules before judging one price against another. A better-looking number may reflect different conditions, such as overtime rules, player participation or void terms.
