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In France, odds are written 2.50. In the UK, the same price is written 6/4, and in the United States +150. All three say the same thing: what a stake returns, and therefore the probability the operator assigns to the outcome. The converter below switches between them.
In short: decimal odds = fraction + 1, and implied probability = 1 ÷ decimal odds. So 6/4 = 2.50 = +150 = 40%.
| Decimal | Fractional | American | Probability |
|---|---|---|---|
| 1.25 | 1/4 | −400 | 80.0% |
| 1.50 | 1/2 | −200 | 66.7% |
| 1.91 | 10/11 | −110 | 52.4% |
| 2.00 | 1/1 | +100 | 50.0% |
| 2.50 | 6/4 | +150 | 40.0% |
| 3.00 | 2/1 | +200 | 33.3% |
| 5.00 | 4/1 | +400 | 20.0% |
| 11.00 | 10/1 | +1000 | 9.1% |
It shows what €1 staked returns, stake included. At 2.50, a €10 stake returns €25 if the bet wins: €15 net profit, plus the original €10.
net profit = stake × (odds − 1)
They give net profit relative to the stake, without the stake. At 6/4, a stake of 4 returns 6 in profit. To convert, divide then add 1: 6 ÷ 4 + 1 = 2.50. Odds of 1/1, called “evens”, are 2.00.
decimal odds = numerator ÷ denominator + 1
The sign changes how they read. Positive, they give the net profit on a stake of 100: +150 returns 150 profit for 100 staked, i.e. 2.50. Negative, they give the stake needed to win 100: at −200, you must stake 200 to win 100, i.e. 1.50.
+N → 1 + N ÷ 100 · −N → 1 + 100 ÷ N
In every format, odds imply a probability, called the implied probability: 1 ÷ decimal odds. It is also the strike rate you need just to break even at that price.
This probability includes the bookmaker's margin. Add up the probabilities of a match's three outcomes: the total exceeds 100%, and the difference is the share the operator takes. The margin calculator does this for a whole match.
Odds of 1.10 look safe. They imply a 90.9% chance, which means you must win ten times out of eleven just to avoid losing money. A single loss wipes out the net profit of ten wins.
The shorter the odds, the more the margin weighs on what is left to win. That is why a high strike rate says nothing about profitability, as shown by our study of tipsters.
On every match, we convert each licensed operator's odds into probabilities, strip out the margin, and show who takes the least.
See today's matchesDivide the first number by the second, then add 1. Odds of 6/4 give 6 ÷ 4 + 1 = 2.50 in decimal. Odds of 1/2 give 0.5 + 1 = 1.50.
You must stake 110 to win 100 in net profit. In decimal that is 1.91, an implied probability of 52.4%. It is the standard price for evenly matched two-way bets in the United States.
No. Higher odds pay more because the outcome is less likely. What matters is the gap between the odds offered and the true probability, explained in our guide to the value bet.
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