What odds are and how to read them
How to read decimal odds, how the return is calculated, how to convert odds into probability and how to find the bookmaker's margin from the sum of the probabilities — with worked tables.
The number you look at most often on a betting site is the odds, but many people read it simply as “how much it will pay”. In fact every price says two things at once: how much you will receive if the bet wins, and how much chance the bookmaker gives that outcome. Once you learn to read the second, you look at an odds table with quite different eyes.
In Azerbaijan you will mostly come across the decimal format
Three formats are in wide use around the world:
- Decimal — such as 2.50. Widely used in Europe; on the sites accessible from Azerbaijan this is usually the standard format too.
- Fractional (British) — such as 3/2. Used mainly in the United Kingdom and Ireland.
- American (moneyline) — such as +150 or −200. Mainly on North American sites.
On many sites the odds format can be changed in the account settings. If the numbers on the screen do not look familiar to you — for example 17/20 instead of 1.85 — check that setting first.
The advantage of the decimal format is that it is easy to read: the smaller the number, the higher the probability of the outcome according to the bookmaker’s own assessment. 1.20 indicates a strong favourite, 10.00 an unlikely outcome.
How the return is calculated
Two formulas are enough:
Total payout = stake × odds
Net profit = stake × (odds − 1)
The most common mistake comes from here: the decimal price already includes the money you put in. That is, odds of 2.00 do not bring you a profit of twice the stake — on a 20 manat bet the total payout is 40 manat, and 20 manat of that is your own money. The table below gives the calculation for a 20 manat bet.
| Odds | Total payout (20 AZN) | Net profit |
|---|---|---|
| 1.20 | 24.00 AZN | 4.00 AZN |
| 1.50 | 30.00 AZN | 10.00 AZN |
| 1.85 | 37.00 AZN | 17.00 AZN |
| 2.00 | 40.00 AZN | 20.00 AZN |
| 3.00 | 60.00 AZN | 40.00 AZN |
| 6.00 | 120.00 AZN | 100.00 AZN |
Decimal odds do not fall below 1.00, because if they did you would lose money even when the bet won. Odds such as 1.01 return almost nothing: just 0.20 AZN on a 20 AZN bet.
The probability inside the odds
To convert odds into a probability expressed as a percentage, it is enough to divide 100 by them:
Probability (%) = 100 ÷ odds
| Odds | Probability the bookmaker gives |
|---|---|
| 1.20 | 83.3% |
| 1.50 | 66.7% |
| 2.00 | 50.0% |
| 2.50 | 40.0% |
| 4.00 | 25.0% |
| 10.00 | 10.0% |
One important note: this figure is not the “true” probability of the outcome. It is the bookmaker’s own assessment, and its cut — the margin — is built into it. That is exactly why, when you add up all the probabilities in a market, you get more than 100%, not 100%.
Work out the margin yourself in three steps
- Write down the odds for every possible outcome in the market.
- Convert each one into a percentage with the formula
100 ÷ odds. - Add the percentages together.
The figures below do not belong to a real match; they are a worked example.
| Outcome | Odds | Probability (100 ÷ odds) | “Fair” odds |
|---|---|---|---|
| 1 — home side | 1.75 | 57.14% | 1.85 |
| X — draw | 3.80 | 26.32% | 4.02 |
| 2 — away side | 4.50 | 22.22% | 4.76 |
| Total | 105.68% | 100.00% |
The part of the total above 100 — here 5.68 percentage points — is the margin (“overround” in the international literature). The fourth column shows how the odds would look if the margin were taken out: for all three outcomes the price offered is lower than the “fair” price.
The share the bookmaker actually takes from turnover is somewhat lower, and it is calculated like this: 5.68 ÷ 105.68 = 5.38%. For two-way markets the method is the same — odds of 1.85 and 1.95, for example, give 54.05% + 51.28% = 105.34%.
The practical way to compare bookmakers
This is the main benefit of calculating the margin: you look at the odds for the same match on two different sites and see which of them takes the smaller cut.
| Outcome | Bookmaker A | Bookmaker B |
|---|---|---|
| 1 | 1.75 | 1.78 |
| X | 3.80 | 3.85 |
| 2 | 4.50 | 4.55 |
| Sum of probabilities | 105.68% | 104.13% |
On a single match the difference looks small, but over hundreds of bets it adds up. Even so, it would not be right to look at one market alone and conclude that “this bookmaker’s margin is lower”:
- The margin varies by sport, by competition and by market type; in the major football leagues it is usually lower, and in less well-known events considerably higher.
- On the main markets (1X2, totals) the odds are more competitive; on exotic markets the margin increases.
- On live betting the margin is usually higher than on the pre-match line.
So carry out the comparison over several days and on exactly the markets you bet on.
Why odds change
The line does not stay fixed. Two things mainly move a price: new information (team line-ups, injuries, the weather) and the flow of bets — when a lot of money comes in on one side, the odds on that side are cut.
This has one practical consequence for you: at the moment you confirm the bet the odds may differ from what they were when you added the selection to your slip. Many sites have an “accept odds changes” setting for this reason. Always check which price was recorded on your slip after confirmation — settlement is made on exactly that number.
In short
- Total payout = stake × odds; net profit = stake × (odds − 1).
- Probability = 100 ÷ odds. This is the bookmaker’s price, not the truth.
- Add up the probabilities of all the outcomes: whatever remains above 100% is the margin.
- Higher odds do not mean a better offer — they are simply the price of a less likely outcome.
- Over the long run the margin works against the bettor; for that reason treat betting as an entertainment expense.
You can get to know the general mechanism of betting in the How sports betting works guide. If you feel you are losing control over your play, read the information on the Responsible gambling page. Betting is only for persons aged 18 and over.