Decimal odds are the easiest format to calculate with. They are standard across Europe, Australia, Canada and much of the world, and many apps let you switch to them. If you understand multiplication, you understand decimal odds.
The one rule
Your total return = stake × decimal odds.
That is it. The number already includes your original stake. So at 2.50, a 10 stake returns 25 in total: your 10 back plus 15 profit.
To get just the profit, subtract the stake: profit = stake × (odds − 1).
Worked examples
A favorite at 1.40
- Stake 50 × 1.40 = 70 total return
- Profit = 70 − 50 = 20
A coin flip at 2.00
- Stake 50 × 2.00 = 100 total return
- Profit = 50 (even money)
An underdog at 3.75
- Stake 50 × 3.75 = 187.50 total return
- Profit = 137.50
Anything below 2.00 is a favorite (you win less than you risk). Anything above 2.00 is an underdog (you win more than you risk). Exactly 2.00 is even money.
The lowest possible decimal odds are just above 1.00. Odds of 1.01 would mean you risk 100 to win 1, which is an overwhelming favorite.
Decimal odds and probability
Decimal odds convert to implied probability with one division:
Implied probability = 1 ÷ decimal odds
| Decimal odds | Implied probability | |---|---| | 1.25 | 80.0% | | 1.50 | 66.7% | | 1.91 | 52.4% | | 2.00 | 50.0% | | 2.50 | 40.0% | | 4.00 | 25.0% | | 10.00 | 10.0% |
You can go the other way too: fair decimal odds = 1 ÷ probability. If you believe a team wins 40% of the time, fair odds are 1 ÷ 0.40 = 2.50. If the market offers 2.80, that is better than your fair price. If it offers 2.20, it is worse.
Spotting the house margin
Add the implied probabilities of all outcomes in a market. In a fair world they would add up to exactly 100%. In practice they add up to more.
Example tennis match:
- Player A: 1.80 → 55.6%
- Player B: 2.05 → 48.8%
- Total: 104.4%
That extra 4.4% is the overround or margin, also called the vig. Lower is better for the player. Our vig guide explains how it works in detail.
Converting decimal to American and fractional
To American:
- If decimal is 2.00 or higher: (decimal − 1) × 100, with a plus sign. 2.50 → +150.
- If decimal is below 2.00: −100 ÷ (decimal − 1). 1.50 → −100 ÷ 0.5 = -200.
To fractional:
- Subtract 1 and write it as a fraction. 2.50 → 1.50 → 3/2. 1.50 → 0.50 → 1/2.
Why many people prefer decimal odds
- No sign confusion. There are no plus or minus numbers to keep straight.
- Easy comparison. Higher is always a bigger payout. 2.10 beats 2.05, full stop.
- Easy parlay math. To combine picks into a parlay, multiply the decimal odds. Three picks at 1.90 each give 1.90 × 1.90 × 1.90 = 6.86. A 10 stake would return 68.60.
That last point is a big reason decimal odds help you understand parlays. You can see how quickly the payout grows, and also how the implied probability shrinks: 1 ÷ 6.86 is about 14.6%. Read more in what is a parlay.
Decimal odds in three-way markets
Soccer often has three outcomes: home win, draw, away win. Decimal odds handle this cleanly.
- Home: 2.10 (47.6%)
- Draw: 3.40 (29.4%)
- Away: 3.60 (27.8%)
- Total: 104.8%
The same rule applies: stake × odds = return. See soccer 3-way odds for how draws change your thinking.
Common mistakes
- Forgetting the stake is included. At 3.00, a 10 stake returns 30, but your profit is 20, not 30.
- Treating 1.20 as "safe." It implies about 83%. That still means losing roughly one in six.
- Comparing different formats without converting. Convert everything to one format first.
Practice for free
If you want to get fluent with decimal odds, try reading real lines and writing down the implied probability for each side. MockSport lets you make free play-money picks on real lines, so you can test your reads and watch your results over time without risking anything. Start on the odds page or browse the learn hub.
FAQ
What do decimal odds of 1.50 mean?
A 1.50 price returns 1.50 for every 1 staked, including the stake. A 100 stake returns 150, which is 50 profit. The implied probability is 1 ÷ 1.50 = 66.7%.
Are higher decimal odds better?
Higher odds mean a bigger payout, but also a lower implied chance of winning. "Better" only means the price is higher than the true probability justifies.
How do I convert decimal odds to a percentage?
Divide 1 by the decimal odds and multiply by 100. For 2.50, that is 1 ÷ 2.50 = 0.40, or 40%.