Odds converter
American, decimal and fractional odds are three ways of writing the same price. Decimal odds are the total return for each 1 staked, so −110 is 1.909, 10/11 in fractional, and implies a 52.38% chance (margin included). Enter a price in any format below to convert it; the formulas and a table of common prices follow.
Convert odds
American odds accept a plain minus sign or the typographic one (−). Fractional odds are two numbers with a slash, such as 5/2.
The formulas
Every conversion goes through decimal odds, the total amount returned for each 1 staked, stake included.
American to decimal: positive odds +A: decimal = 1 + A ÷ 100. Negative odds −A: decimal = 1 + 100 ÷ A.
Decimal to American: decimal 2.00 or more: +(decimal − 1) × 100. Below 2.00: −100 ÷ (decimal − 1).
Fractional to decimal: a/b: decimal = 1 + a ÷ b.
Implied probability = 1 ÷ decimal.
−150 is a 150 stake to win 100. Decimal: 1 + 100 ÷ 150 = 1.667. Fractional: 100/150 = 2/3. Implied probability: 1 ÷ 1.667 = 60.00%. +250 is a 100 stake to win 250: decimal 3.50, fractional 5/2, implied probability 28.57%.
The calculator rounds only what it shows: American odds to whole numbers, decimal odds to two or three places and probabilities to two decimal places. The conversions themselves use the unrounded values.
Reading each format
- American (moneyline) odds are the standard at U.S. sportsbooks. A minus price is what you stake to win 100; a plus price is what a 100 stake wins. Prices between −100 and +100 do not exist: +100 and −100 are the same price, even money.
- Decimal odds are common in Europe, Canada and Australia. They include the stake: 2.50 returns 2.50 for each 1 staked, a profit of 1.50.
- Fractional odds are traditional in the UK and Ireland. They show profit to stake: 5/2 wins 5 for every 2 staked. 1/1 is even money, sometimes written “evens”.
Some prices have no tidy fraction. When a decimal price cannot be written exactly with a denominator up to 10,000, the calculator shows the closest fraction marked with ≈.
Common odds in every format
| American | Decimal | Fractional | Implied probability |
|---|---|---|---|
| −1,000 | 1.10 | 1/10 | 90.91% |
| −500 | 1.20 | 1/5 | 83.33% |
| −300 | 1.333 | 1/3 | 75.00% |
| −250 | 1.40 | 2/5 | 71.43% |
| −200 | 1.50 | 1/2 | 66.67% |
| −175 | 1.571 | 4/7 | 63.64% |
| −150 | 1.667 | 2/3 | 60.00% |
| −130 | 1.769 | 10/13 | 56.52% |
| −120 | 1.833 | 5/6 | 54.55% |
| −110 | 1.909 | 10/11 | 52.38% |
| −105 | 1.952 | 20/21 | 51.22% |
| +100 (even money) | 2.00 | 1/1 | 50.00% |
| +105 | 2.05 | 21/20 | 48.78% |
| +110 | 2.10 | 11/10 | 47.62% |
| +120 | 2.20 | 6/5 | 45.45% |
| +130 | 2.30 | 13/10 | 43.48% |
| +150 | 2.50 | 3/2 | 40.00% |
| +175 | 2.75 | 7/4 | 36.36% |
| +200 | 3.00 | 2/1 | 33.33% |
| +250 | 3.50 | 5/2 | 28.57% |
| +300 | 4.00 | 3/1 | 25.00% |
| +400 | 5.00 | 4/1 | 20.00% |
| +500 | 6.00 | 5/1 | 16.67% |
| +1,000 | 11.00 | 10/1 | 9.09% |
Implied probability is what the price alone says, margin included: the two sides of a real market add up to more than 100%. The no-vig calculator removes that margin.
Questions
Is −110 the same as 1.91?
Almost. −110 is exactly 1 + 100 ÷ 110 = 1.90909... in decimal, shown here as 1.909. Many sportsbooks round it to 1.91, which implies 52.36% instead of 52.38%. The difference is small but real.
Why is +100 the same as −100?
Both mean a stake wins exactly its own amount: decimal 2.00, fractional 1/1, an implied probability of 50%. The calculator shows even money as +100.
What does implied probability mean?
It is the chance of winning at which the price would break even, with the sportsbook’s margin included. It is not the true chance of the result, which nobody knows for certain.
Which format should I use?
Any of them: they describe the same price. Decimal odds make the arithmetic simplest, which is why the formulas on this page go through them.
Arithmetic, not advice
These calculators do arithmetic on the numbers you enter. They do not know the true chance of any result, they do not predict outcomes, and using them does not make betting profitable. Betting involves financial risk, and no research or model makes gambling safe or removes that risk.
StatsNext is for people 18 and older. Being 18 or older does not mean sports betting is legal for you: follow the laws and legal gambling age requirements where you live. Never wager money you cannot afford to lose, and do not chase losses. If gambling stops feeling like it is within your limits, free and confidential help is available 24/7 from the National Problem Gambling Helpline: 1-800-MY-RESET (1-800-697-3738). More resources are on the Responsible Gambling page.
StatsNext is a research platform, not a sportsbook; it does not accept wagers or guarantee results (Research Disclaimer, Responsible Gambling).
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