Odds converter and implied probability calculator
Type odds in any format: −110, +150, 1.91 or 5/4. The other formats and the implied probability update instantly. Add the price of the opposite side to see the vig.
What an odds converter does
An odds converter translates the same betting price between three formats: American (US), decimal (Europe, Australia, Canada) and fractional (UK and Ireland), and into implied probability. The format never changes the payout: +150, 2.50 and 3/2 are the same bet, returning 1.5 times the stake in profit.
How to use the odds converter
- Enter odds in any field: American, decimal, fractional or a probability in percent.
- Read the other formats and the implied probability: they update as you type.
- For a two-way line, enter the price of the other side to get the vig and the no-vig (fair) probabilities.
- Tap a row in the odds conversion chart to load it into the converter.
How to read the result
Implied probability equals 1 divided by decimal odds. It is the price the sportsbook set, not the true chance: it includes the margin, so both sides of a line add up to more than 100%.
The fair probability divides each implied probability by their sum. A bet has value only if you rate the outcome higher than its fair probability.
How to convert odds by hand
Odds conversion chart
Common prices in three formats and the probability they imply. Tap a row to open it in the converter.
| Decimal | American | Fractional | Implied probability |
|---|---|---|---|
| 1.20 | −500 | 1/5 | 83.3% |
| 1.25 | −400 | 1/4 | 80.0% |
| 1.33 | −303 | 1/3 | 75.2% |
| 1.40 | −250 | 2/5 | 71.4% |
| 1.50 | −200 | 1/2 | 66.7% |
| 1.60 | −167 | 3/5 | 62.5% |
| 1.67 | −149 | 2/3 | 59.9% |
| 1.75 | −133 | 3/4 | 57.1% |
| 1.80 | −125 | 4/5 | 55.6% |
| 1.83 | −120 | 5/6 | 54.6% |
| 1.91 | −110 | 10/11 | 52.4% |
| 2.00 | +100 | 1/1 | 50.0% |
| 2.10 | +110 | 11/10 | 47.6% |
| 2.20 | +120 | 6/5 | 45.5% |
| 2.50 | +150 | 3/2 | 40.0% |
| 2.75 | +175 | 7/4 | 36.4% |
| 3.00 | +200 | 2/1 | 33.3% |
| 3.50 | +250 | 5/2 | 28.6% |
| 4.00 | +300 | 3/1 | 25.0% |
| 5.00 | +400 | 4/1 | 20.0% |
| 6.00 | +500 | 5/1 | 16.7% |
| 11.00 | +1000 | 10/1 | 9.1% |
What to do next
Compare the implied probability with how often such picks actually win. On the BetBuddyRank capper leaderboard the expected hit rate of every pick is computed exactly this way, from the no-vig price, and the index shows who beats that price consistently.
Odds formats compared
| Format | Where | Example | What it shows |
|---|---|---|---|
| American | US, Canada | +150 / −200 | Profit on 100, or the stake to win 100 |
| Decimal | Europe, Australia | 2.50 | Total return including the stake |
| Fractional | UK, Ireland | 3/2 | Net profit relative to the stake |
| Implied probability | Analytics, exchanges | 40% | The chance priced into the odds |
FAQ
How do you convert American odds to decimal?
For positive odds divide by 100 and add 1: +150 becomes 2.50. For negative odds divide 100 by the number and add 1: −110 becomes 1.91.
What does −110 mean in betting?
You stake 110 to win 100 in profit. In decimal it is 1.91 with an implied probability of 52.4%. It is the standard price for NFL and NBA spreads and totals.
How do you turn odds into a percentage?
Divide 1 by the decimal odds and multiply by 100. Odds of 2.00 mean 50% and odds of 1.50 mean 66.7%. That percentage still includes the sportsbook margin.
What is the vig?
The vig, or margin, is the extra the sportsbook adds to the probabilities to make a profit. If both sides of a line add up to 104.8%, as with −110 on each side, the vig is about 4.5%.
Are decimal odds better than fractional odds?
No. The format only writes the same price differently. The better price is simply the higher payout for the same outcome at another sportsbook.