Decimal odds explained
How decimal odds work, how to turn them into returns and profit, and why the higher number is the better price for the same outcome.
Decimal odds are the simplest way to write a price. One number tells you how much comes back for every unit you stake if the selection wins, and that figure already includes the stake. They are the standard format in continental Europe, Australia and New Zealand, and widely used in Canada, the UK and Ireland alongside American or fractional odds.
How to read a decimal price
Multiply your stake by the decimal odds and you have your return: the full amount paid out on a win.
Return = stake × decimal odds
Take a price of 2.50 and a stake of 10. The return is 10 × 2.50 = 25.00. If the selection loses, you lose the 10 you staked and nothing comes back.
Because the stake is built in, a price of 2.00 means you get back exactly twice what you put in, and a price of 1.50 means you get back one and a half times your stake.
Returns vs profit
The return and the profit are not the same thing, and mixing them up is an easy mistake.
- Return is everything paid out on a win: your stake plus your winnings.
- Profit is only the winnings: the return minus the stake.
Profit = stake × (decimal odds − 1)
At 2.50 with a stake of 10, the return is 25.00 and the profit is 25.00 − 10 = 15.00, which is the same as 10 × 1.50.
Here is the same stake of 10 at a range of prices:
| Decimal odds | Return on 10 | Profit on 10 |
|---|---|---|
| 1.50 | 15.00 | 5.00 |
| 1.80 | 18.00 | 8.00 |
| 2.00 | 20.00 | 10.00 |
| 2.50 | 25.00 | 15.00 |
| 4.00 | 40.00 | 30.00 |
| 11.00 | 110.00 | 100.00 |
Two things stand out. A price below 2.00 (often called odds-on) pays less profit than the stake: at 1.80, risking 10 wins 8. A price above 2.00 (odds-against) pays more profit than the stake: at 4.00, risking 10 wins 30.
What decimal odds say about probability
Every price carries an implied probability, and in decimal format it is one division away:
Implied probability = 1 ÷ decimal odds
So 2.50 implies 1 ÷ 2.50 = 40%, 2.00 implies 50%, and 1.80 implies about 55.6%. This is also the break-even win rate: a selection priced at 2.50 has to win 40% of the time just to come out level over many bets. The implied probability guide goes into this in more detail.
If you add up the implied probabilities of every outcome in a market, you usually get more than 100%. In a two-way market priced at 1.91 on both sides, each side implies about 52.36%, for a total of about 104.71%. The 4.71 percentage points above 100% are the overround, one measure of the sportsbook's margin (as a share of all money staked it is about 4.5%). Remove it and both sides become 2.00, the fair price. See what the vig is and fair odds for how that works, or use the no-vig calculator.
Why a small difference in price matters
With decimal odds, comparing prices is easy: for the same outcome, the higher number is the better price. It is worth doing because small gaps add up.
Say one sportsbook offers 2.10 and another offers 2.05 on the same team, and you stake 50:
| Price | Return on 50 | Profit on 50 | Break-even win rate |
|---|---|---|---|
| 2.10 | 105.00 | 55.00 | 47.6% |
| 2.05 | 102.50 | 52.50 | 48.8% |
The higher price pays 2.50 more on a win and needs a lower win rate to break even. That is the whole idea behind OddsKeepr: it lines up the prices at sportsbooks licensed where you are, so the best one is easy to spot. The guide to comparing odds explains more.
Decimal odds in other formats
The same price can be written three ways. To convert from decimal:
- Fractional: subtract 1 and write the result as a fraction in its lowest terms.
2.50becomes 1.50, which is 3/2. Some prices only round to a traditional fraction:1.91is shown as 10/11. - American, at 2.00 or above: subtract 1 and multiply by 100.
2.50becomes +150. - American, below 2.00: divide -100 by (decimal odds − 1).
1.80becomes -100 ÷ 0.80 = -125.
| Decimal | American | Fractional |
|---|---|---|
| 1.50 | -200 | 1/2 |
| 1.80 | -125 | 4/5 |
| 2.00 | +100 | 1/1 |
| 2.50 | +150 | 3/2 |
| 4.00 | +300 | 3/1 |
The converter does this for any price:
Read as American odds: +150
+150 = 2.50 = 6/4 = 40.0%
The implied probability includes any margin in the price. A fair price comes from removing it.
To learn the other two formats in full, read American odds explained and fractional odds explained.
Decimal odds in parlays
Decimal odds make a parlay's price easy to work out: you multiply the prices. A parlay of a 1.50 leg and a 2.20 leg is priced at 1.50 × 2.20 = 3.30. A stake of 10 returns 33.00 if both legs win, a profit of 23.00; if either leg loses, the whole 10 is lost. If the 2.20 leg is void, most sportsbooks count it as 1.00, so the parlay drops to 1.50 × 1.00 = 1.50; each sportsbook's terms set the exact rule, including what happens on a push. The parlays and accumulators guide and the parlay calculator cover the rest.
Gambling always carries a risk of losing money, so only stake what you can afford to lose, and help is available if it stops being fun. Before using any sportsbook, check that it is licensed where you are.