Convert odds between decimal, fractional and american instantly. Calculate implied probability and bookmaker margin.
Enter the odds for all outcomes of an event to calculate the bookmaker's built-in margin and the true no-vig probabilities.
| Decimal | Fractional | American | Implied Prob. |
|---|---|---|---|
| 1.20 | 1/5 | -500 | 83.3% |
| 1.33 | 33/100 | -303 | 75.2% |
| 1.50 | 1/2 | -200 | 66.7% |
| 1.67 | 67/100 | -149 | 59.9% |
| 1.80 | 4/5 | -125 | 55.6% |
| 1.91 | 10/11 | -110 | 52.4% |
| 2.00 | 1/1 | +100 | 50.0% |
| 2.10 | 11/10 | +110 | 47.6% |
| 2.50 | 3/2 | +150 | 40.0% |
| 3.00 | 2/1 | +200 | 33.3% |
| 3.50 | 5/2 | +250 | 28.6% |
| 4.00 | 3/1 | +300 | 25.0% |
| 5.00 | 4/1 | +400 | 20.0% |
| 6.00 | 5/1 | +500 | 16.7% |
| 10.00 | 9/1 | +900 | 10.0% |
Odds represent the bookmaker's payout for a winning bet, but they also embed a profit margin (also called overround, juice, or vig). The three main formats — decimal, fractional, and American — all express the same information differently. Decimal odds (e.g., 1.90) are used across Europe and most of the world. Fractional odds (e.g., 9/10) are traditional in the UK. American odds (e.g., -110) are standard in the US.
Implied probability is calculated as 1 / decimal odds. For example, odds of 2.00 imply a 50% probability. However, when you add up the implied probabilities for all outcomes of an event, the total exceeds 100%. This excess is the bookmaker's margin — their built-in profit. A typical football match might have a combined implied probability of 105%, meaning the bookmaker has a 5% margin.
No-vig (or true) probabilities remove the bookmaker's margin to reveal what the bookmaker actually believes the real probabilities are. To calculate no-vig probabilities, divide each implied probability by the total implied probability. For example, if a two-outcome event has implied probabilities of 52.63% and 47.62% (total 100.25%), the no-vig probabilities are 52.50% and 47.50%.
Understanding margin is crucial for value betting. Bookmakers with lower margins (like Pinnacle at 1-3%) offer odds closer to the true probability, making it easier to find positive EV bets. High-margin bookmakers (5-10%+) make it much harder to find value. OdinPicks always compares against Pinnacle no-vig odds to ensure our EV calculations use the most accurate benchmark available.