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 favorite. 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 favorite 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%

  • William Hill Casino

    $500 Risk Free Bet

    To be eligible for this Promotion, all eligible Patrons must place their first real money sports wager via the William Hill mobile app or desktop site, within 7 days of opening a William Hill NJ Account. If their Qualifying Wager is graded as a Loss the Participant will earn a one-time Free Bet token equal to the lessor of: 1) The full value of the Qualifying Wager or 2) $500 (“Free Bet(s).
  • 888 Sport

    $500 Welcome Bonus

    Player must be at least 21 years old, located in New Jersey, has completed the full registration process with us.888sport.com, makes a first deposit equal to or greater than $10 and may be entitled to a Welcome Bonus of 100% up to $500 on the players first deposit at us.888sport.com.
  • Unibet Sportsbook

    Play Now

    Join Unibet Sportsbook today and once you add funds, we'll insure your first cash bet - get up to $500 back if you don't hit a winner. Make your first cash bet on any event. If your first settled cash bet loses, you will receive a refund to your account equal to the amount of your losing wager (up to $500). Your first cash bet ($10 or over) will qualify. You will receive the refund within 72 hours.
  • Sugar House

    100% Up To $250 Deposit Match Bonus

    Player must create a new account, make a first deposit up to $250 to get a Deposit Match Bonus. Use code 250MATCH.
  • FanDuel Sportsbook Review

    $500 Risk Free Bet

    New Sportsbook Customers Only NJ. Join FanDuel Sportsbook today and make your first bet. If you lose, we'll give you a refund of up to $500 in site credit (within 72h). Your first bet will qualify (If you have multiple selections on one betslip, it will be the first selection you made)
  • Draft Kings Sportsbook

    Get a deposit bonus up to $500!

    Join Draft Kings today and with your first deposit of $5 or more, you will receive a free $3 ticket to play in any $3 paid contest. A user’s first deposit (min. $5) made between 5/13/20 – 8/17/20 qualifies the user to receive up to $500 in bonus funds in the form of site credits that can only be used on DraftKings. Bonus amount is equal to 20% of that deposit amount, not to exceed $500 (the user must deposit $2,500 to be eligible to receive the maximum possible bonus amount of $500).
  • Caesars

    $300 Free Bet

    Make your first deposit using SPORTS300 and we will match your first sports bet up to $300! Cash bet must have minimum odds of -200. On Parlay wagers, each legs must have odds of -200 or greater.
  • Bet America

    Bet $50 Get $50 [code: BET50]

    Join BetAmerica today for an exclusive Bet $50 and Get $50 using code [BET50] on your next sports bet. Register today and enjoy our Freeplay contests where you can use your sports and casino knowledge to win $1000's in prizes every week.

Latest news