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Decimal Odds
Last reviewed 24 September 2026
What is Decimal Odds?
The European odds format, expressing total return per unit staked including the stake itself. Odds of 2.50 return 2.50 for every 1.00 staked.
Key takeaways
- Decimal odds give the total return per unit staked, so a 10.00 stake at 2.50 returns 25.00, including 15.00 profit.
- Implied probability is one divided by the odds, so 2.50 implies 40%.
- Summing implied probabilities across a market shows the overround, such as 105.3% for a two-way market priced 1.90 and 1.90.
Why it matters
Decimal odds are the default in Europe, Australia and Canada, and increasingly the format serious bettors use everywhere, because the arithmetic is trivial: return equals stake multiplied by the odds. A 10.00 stake at 2.50 returns 25.00, of which 15.00 is profit. Converting to implied probability is equally direct, being one divided by the odds, so 2.50 implies 40%. That transparency is why odds-comparison tools, trading screens and model outputs almost always work in decimals even when the customer-facing site shows something else.
The format matters commercially because it makes margin visible. Add up the implied probabilities of every outcome in a market and the amount above 100% is the operator's overround. In a two-way market priced 1.90 and 1.90, the implied probabilities are 52.6% each, totalling 105.3%, so the book carries a 5.3% margin. Sportsbooks in mature markets have competed that margin down on headline events while holding it wider on niche leagues and in-play, and decimal pricing is what lets a bettor see the difference at a glance.
Frequently asked questions
How do decimal odds work?
Decimal odds express the total return for each unit staked, including the stake itself. Multiply the stake by the odds to get the return: a 10.00 stake at 2.50 returns 25.00, of which 15.00 is profit. The format is the default in Europe, Australia and Canada and is widely used on trading screens, in models and by odds-comparison tools.
How do you convert decimal odds to implied probability?
Divide one by the decimal odds. Odds of 2.50 imply a probability of 40%, and odds of 1.90 imply about 52.6%. Because bookmakers build margin into their prices, the implied probabilities of every outcome in a market add up to more than 100%, and the amount above 100% is the overround, which shows how much margin the book carries.
What is the difference between decimal and fractional odds?
Decimal odds show the total return including the stake, while fractional odds show profit relative to the stake. A decimal price of 3.50 is the same as fractional 5/2: a stake of 2 wins 5 profit and returns 7 in total. To convert fractional odds to decimal, divide the top number by the bottom number and add one.