Odds Conversion

This tool allows sports bettors to quickly and accurately convert odds between the American, decimal and fractional formats. The right-hand column of our betting odds converter also tells you the implied probability of winning in each case.

This odds converter is a vital tool for sports bettors, because you will often see the odds presented in different formats. The American format is naturally the most common at sportsbooks in the United States, but horse racing odds are typically presented in the fractional format.

Decimal odds are common in Europe and Canada, so you might see them when reading soccer, tennis and hockey picks. It helps to be able to quickly convert the odds to a format you understand, as that will help you make your wagering decisions.

There are some reasonably complex mathematical equations underpinning this odds converter. Using our betting odds converter means you do not need to do the math yourself. You can simply let BetTodayUSA work it out for you. Read on to learn more about each odds format and how this odds converter tool can benefit you.

American Odds

American odds can either begin with a minus symbol or a plus symbol. If you see a minus sign, it tells you the amount you would need to wager in order to generate a $100 profit. If the odds are -500, you must risk $500 in order to make a $100 profit. If the odds are -225, you need to stake $225 to earn a $100 profit.

If your bet is a winner, you get your stake back, so your return on a successful $225 bet at odds of -225 would be $325 (a $100 profit and the return of your $225 stake). You do not need to wager $100. It is just a guide. You could wager $20 at odds of -225 and make a profit of $8.89 if successful, or wager $5,000 and make a profit of $2222.22.

If the odds begin with a plus sign, it tells you the profit you stand to earn from a $100 bet. If you successfully wager $100 at odds of +125, you make a $125 profit. Once again, your stake is returned if your bet wins, so your return would be $225. If you wager $100 at odds of +900, you will earn a return of $1,000 if successful ($900 profit and $100 stake back). Check out the third column of this odds converter tool to see the American odds.

Fractional Odds

Horse racing odds are generally presented in the fractional format in the United States. It helps to have a thorough understanding of this format when betting on the Kentucky Derby, the Breeders’ Cup Classic and other big races.

Essentially, the number on the left of the backslash is the profit you will earn by wagering the number on the right. If the odds are 9/1, it tells you that you will earn a $9 profit for every $1 you wager. You get your $1 stake back, so your return would be $10. You can therefore see that odds of 9/1 are equivalent to +900 in our odds converter tool.

If the number to the right of the backslash is larger than the number on the left, it is odds-on and generally the favourite. If you see odds of 1/4, it tells you that you will make a $1 profit for every $4 you wager. Fractional odds of 1/4 are therefore equivalent to American odds of -400, as you can see from this betting odds converter.

Decimal Odds

Decimal odds tell you the return you stand to make from a wager, as opposed to simply the profit. If you see odds of 1.20, it tells you that you will be returned $1.20 for every $1 you wager if your bet is successful. That includes a profit of $0.20 and the return of your $1 stake.

If the decimal odds are 101.00, you will earn a $101 return for every $1 you wager (a $100 profit and the return of your $1 stake). American odds of +900 and fractional odds of 9/1 therefore amount to decimal odds of 10.00, as you can see on the odds calculator.

Converting Odds

As a general rule, you simply add 1 to fractional odds to calculate the decimal odds. Odds of 4/1 amount to 5.00, odds of 5/1 amount to 6.00 and so on. Odds of 1/5 amount to 1.20 (which is essentially 1 and a fifth). To convert from decimal odds to positive American odds, you can generally subtract by 1 and then multiply by 100. You will soon get the hang of it.

The implied probability of winning column on our odds converter is also useful, because it tells you whether you are betting on a heavy favourite or an underdog. The most common set of odds for U.S. sports bettors is -110, as that is generally what you will find on sides and totals.

Using the knowledge gained from our betting odds converter, you can quickly work out that -110 amounts to 10/11 in fractional odds, or 1.91 in decimal odds. It is just below even money, so the house is taking an edge on either side of the bet.

Odds of -110 give an implied probability of 52.4%, but in reality, your chances of winning are 50-50, so the house is always taking a 2.4% cut. Use this odds converter in tandem with our free bet calculator to quickly work out the returns you can expect from any bet you might be interested in.

Fractional Decimal American Implied Probability Of Winning
1/5 1.20 -500 83.3%
2/9 1.22 -450 81.8%
1/4 1.25 -400 80%
2/7 1.29 -350 77.8%
3/10 1.30 -333.3 76.9%
1/3 1.33 -300 75%
4/11 1.36 -275 73.3%
4/9 1.44 -225 69.2%
1/3 1.33 -300 75%
5/4 2.25 125 44.4%
11/8 2.38 137.5 42.1%
9/1 10.00 900 10%
10/1 11.00 1000 9.1%
20/1 21.00 2000 4.8%
50/1 51.00 5000 2%
100/1 101.00 10000 1%
1000/1 1001.00 100000 0.1%

Latest news