Understanding Roulette Odds

Understanding roulette odds can help you make smarter betting decisions. Whether you’re spinning the wheel at online roulette sites or in a land-based casino, this guide explains what you need to know.

We’ll show you the true probabilities behind each roulette bet. This can assist with developing an effective roulette strategy you can use on European, American, and other variants of the casino table classic.

Understanding Roulette Odds

Roulette is one of the most exciting games you can play at the best online casinos, but understanding how odds work is essential. That is, if you want to improve your experience and make informed bets.

In simple terms, the roulette odds represent the likelihood of a specific outcome on the wheel. For instance, you could bet on the ball landing on a single number like 7 or on a broader option like red or black. Each outcome has specific odds and knowing these can help you play smarter.

Odds are essential because they give you insight into the risk of each type of bet. By understanding roulette odds, you can estimate your risk. In roulette, the odds are based on the total numbers on the wheel and how many of those pockets align with your bet.

Odds, Probability, and Payouts Explained

Though the terms “odds,” “probability,” and “payout odds” are often used interchangeably, they actually refer to different things. For UK roulette players, knowing the differences can greatly improve their gameplay when learning how to play roulette for the first time.

🎲 Odds

Odds in roulette describe the likelihood of winning compared to losing. Instead of showing the proportion of all possible outcomes, they focus on the ratio of “losing outcomes” to “winning outcomes.”

Using the same example (betting on 7 in European roulette), the odds of winning are:

Odds = 1:36

This ratio means that for every time the ball lands on your chosen number, there are 36 times it won’t. Odds provide a clear way to understand your risk versus reward.

🎲 Probability

Probability is the mathematical chance of an event happening, expressed as a fraction, decimal, or percentage. It’s calculated by dividing the number of successful outcomes by the total number of possible outcomes.

For example, in European roulette, the wheel has 37 pockets (numbers 0 to 36). The probability of the ball landing on a single number, such as 7, is:

Probability = 1 ÷ 37 ≈ 0.027 or 2.7%

This means that, in theory, if you spin the wheel 37 times, the ball should land on the number 7 once.

🎲 Payout Odds

Payout odds determine how much online roulette sites pay out if your bet wins. These are usually expressed as ratios like “35 to 1” or “2 to 1.”

It’s important to note that payout odds are set slightly lower than the true odds, which gives the casino its edge, often referred to as the house edge.

• For instance, a straight-up bet on a single number pays 35 to 1. This means if you place a £1 bet and win, you receive £35 in winnings plus your original £1 stake back, totalling £36.
• However, the true odds of winning are 1 in 37 (in European roulette), meaning the casino pays slightly less than the actual chances of success.
• This discrepancy between true odds and payout odds ensures the casino stays profitable over time, which is why roulette remains a favourite for both players and operators.

Roulette Wheel Types and Their Effect on Your Odds

Types of Odds You Get from Roulette Bets

When it comes to roulette, bets are split into two main types: inside bets (on specific numbers or combinations) and outside bets (on broader categories like colours or odd/even). Each type has its own odds, risks, and payouts.

🎯 Straight-Up Bet (Single Number)

This is the riskiest bet you can make in roulette, but also the most rewarding. While the payout is 35 to 1, the actual odds are 36 to 1, giving the house a slight edge.

• What it is: Betting on a single number (e.g., 7).
• Payout: 35 to 1
• Actual Odds: 1 in 37 (≈ 2.70%)
• House Edge: 2.70%

🎯 Split Bet (Two Numbers)

This bet comes with slightly better odds at best payout sites than a straight-up bet but still carries significant risk. The payouts are smaller but more frequent.

• What it is: Betting on two numbers next to each other, placing the chip on the line between them (e.g., 17 and 18).
• Payout: 17 to 1
• Actual Odds: 2 in 37 (≈ 5.41%)
• House Edge: 2.70%

🎯 Street Bet (Three Numbers)

Street bets strike a balance between risk and reward, with decent odds and moderate payouts.

• What it is: Betting on three consecutive numbers in a row (e.g., 1, 2, 3). Place the chip at the edge of the row.
• Payout: 11 to 1
• Actual Odds: 3 in 37 (≈ 8.11%)
• House Edge: 2.70%

🎯 Corner Bet (Four Numbers)

A corner bet provides wider coverage of the table while maintaining a reasonable payout.

• What it is: Betting on four numbers that form a square (e.g., 10, 11, 13, 14). Place the chip at the intersection where all four meet.
• Payout: 8 to 1
• Actual Odds: 4 in 37 (≈ 10.81%)
• House Edge: 2.70%

🎯 Line Bet (Six Numbers)

Line bets are a safer option, offering more coverage and modest payouts.

• What it is: Betting on two adjacent rows of three numbers (six numbers in total). Place the chip at the corner of both rows.
• Payout: 5 to 1
• Actual Odds: 6 in 37 (≈ 16.22%)
• House Edge: 2.70%

🎯 Red/Black

Bet on whether the ball lands on a red or black number.

• Payout: 1 to 1
• Actual Odds: 18 in 37 (≈ 48.65%)
• House Edge: 2.70%

🎯 Odd/Even

Wager on whether the winning number will be odd or even.

• Payout: 1 to 1
• Actual Odds: 18 in 37 (≈ 48.65%)
• House Edge: 2.70%

🎯 High/Low (1–18 or 19–36)

Bet on whether the winning number will fall in the lower (1–18) or upper (19–36) half of the number range.

• Payout: 1 to 1
• Actual Odds: 18 in 37 (≈ 48.65%)
• House Edge: 2.70%

Roulette Odds & Bets: A Summary

Basics of Probability in Roulette Odds

You can learn how to calculate roulette odds and it can help. Although not essential, it can contribute to making smarter betting choices.

Probability is the mathematical chance of a particular outcome. In roulette, it’s calculated by dividing the number of winning outcomes by the total number of possible outcomes:

💡 Formula: Probability = Winning Outcomes ÷ Total Outcomes

With that in mind, here are example using straight bets.

This small difference is why European roulette is the smarter choice for UK players.

Expected Value (EV) and the House Edge

Expected Value shows the average return of a bet over time.

💡 Formula: EV = (Win Probability × Payout) − (Loss Probability × Bet Amount)

Here’s an example using a straight-up £1 bet in European roulette:

This negative return highlights the 2.70% house edge that applies across all European roulette bets.

House Edge and Roulette Odds

The house edge is the built-in advantage that ensures casinos make a profit in the long run. Understanding this concept is key to recognising why roulette payouts are slightly lower than the true probabilities.

While the Gambling Commission ensures that casinos must abide by fundamental rules, there is no law against offering two variants of  roulette. Still, some games simply have better roulette odds and these are the ones you are better off choosing.

For example:

📍 A straight-up win happens 1 in 37 times in European roulette.

📍 If payouts matched true odds, you’d get 36 to 1.

📍 However, the actual payout is 35 to 1 – the difference creates the house edge.

House Edge Formula in Roulette

House Edge = (Expected Loss ÷ Bet Amount) × 100

For European roulette:

House Edge for European vs US Roulette

UK players often prefer European roulette over American roulette due to its lower house edge. With one fewer pocket (37 instead of 38), European roulette gives slightly better odds for every type of bet, avoiding the higher house edge found in American roulette.

The general rule of thumb is to opt for European roulette when playing at UK casinos, whether online or in person.

1. Explanation of House Edge and Its Importance

The house edge is the mathematical advantage that the casino holds on every bet you place. It is expressed as a percentage of your total bet and represents the average amount the casino expects to win over time.

For example, a house edge of 2.70% means that for every £100 you wager, the casino expects to make £2.70 over the long run.

👉 Why It Matters:

1. The house edge ensures long-term profitability for the casino.
2. It helps players understand which games (or bets within a game) are more favourable or risky.
3. It affects your expected return and helps you make smarter, more strategic decisions.

2. How House Edge Varies Between European and American Roulette

The house edge in roulette depends on the type of wheel you’re playing on. There are two main versions of the game:

👉 Why the Difference?

The extra 00 pocket on the American wheel increases the total number of possible outcomes without improving the payout. This makes all bets slightly less favourable for the player compared to European roulette.

For instance:

1. Betting on red in European roulette gives you 18 chances to win out of 37.
2. In American roulette, it’s 18 out of 38, lowering your winning probability but not increasing your payout, thus raising the house edge.

3. Why Odds Are Always Slightly in Favour of the House

In roulette, the payouts are fixed, but the probabilities of winning are slightly worse than the payouts suggest. This discrepancy is how the house gains its edge.

With taxes and levies for UK casinos also factored in, you can expect casinos to want a greater house edge to accommodate them. But you can circumvent this by opting for European variants of roulette odds.

Example – Straight-Up Bet:

Pays 35 to but the actual odds of winning are:

📌 European: 1 in 37 → true odds = 36 to 1

📌 American: 1 in 38 → true odds = 37 to 1

So even though you’re risking your money for what seems like a fair chance, you’re being paid less than the true mathematical value of your bet.

This ensures that:

⛔ The casino always has a statistical advantage.

⛔ Over time, the average player will lose more money than they win.

⛔ The more you play, the more likely the house edge is to affect your results.

Understanding Payouts vs. True Odds

In roulette, players often confuse the concepts of payout odds and true odds. While they may sound similar, they are very different and play a crucial role in how the house maintains its edge. This section clarifies what each term means and how it affects your potential winnings.

1. What Payout Odds Mean

Payout odds refer to the reward you receive if your bet wins. In roulette, each type of bet comes with a fixed payout ratio – this is how much money you win in proportion to your original stake.

The casino sets these payouts, and they are the same whether you play American or European roulette.

For example:

1. A straight-up bet on a single number pays 35 to 1.
2. If you bet £1 and win, you receive £35 in profit plus your £1 bet back, totaling £36.
3. A red/black bet pays 1 to 1.
4. Bet £10 on red, and if red hits, you win £10 and get your original £10 back.

2. How Payout Odds Differ from Actual Probabilities (True Odds)

True odds are the actual probability of winning a particular bet, calculated by dividing the number of winning outcomes by the total number of possible outcomes.

The problem? Payout odds are always slightly worse than true odds. This is how the casino creates and maintains its advantage (the house edge).

If the game paid based on the true odds of 36 to 1 or 37 to 1, the house wouldn’t make a profit. But since the payout is capped at 35 to 1, the expected value of the bet favours the casino.

Example – Straight-Up Bet (Single Number):

1. True odds (European roulette):
2. 1 winning outcome / 37 total numbers = 1 in 37, or 2.70%
3. True odds (American roulette):
4. 1 in 38 = 2.63%
5. Payout odds (both versions):
6. 35 to 1

3. Examples Comparing Payouts and Real Odds

Notice that every payout is just slightly worse than the true probability? This small difference is what gives the house a statistical advantage over time.

Here are a few direct comparisons to show how payout odds and true odds differ:

How Strategies for Roulette Affect Odds

Roulette is a casino game of luck, and no system can promise consistent wins. However, understanding the odds and the house edge can help you make more informed choices.

The best roulette strategies can certainly help you approach the game in a different way. They will not, however, affect the odds or have any direct influence on them.

Placing bets strategically and sensibly, which includes focusing on odds-based approaches in your bets, will help. As always, the best way to minimise losses is to manage your bankroll sensibly and pace yourself to enjoy a longer session at the table.

Tips for Players

Understanding roulette odds isn’t just for statisticians – it’s a practical tool for anyone who wants to maximise fun and minimise losses at the roulette table. Whether you’re a beginner or a regular player, applying a few smart strategies, including useful roulette tips, can make your play more efficient and enjoyable.

1. Use Knowledge of Odds to Play Smarter

Knowing the odds of each type of bet helps you avoid risky decisions and focus on bets that give you a better chance of winning.

For example, betting on a single number offers a 2.7% chance of winning (European) but a 35-to-1 payout. Betting on red gives you nearly a 48.6% chance, with a 1-to-1 payout. Over time, the safer bet helps you last longer.

Suggested Actions:

2. Choose the Right Type of Roulette Game

The roulette variant you play directly affects your odds and potential return. Again, we prefer European Roulette as it’s the smarter choice. This is because it has 37 numbers (1-36 + single zero) which gives it a better house edge (2.70%)

We recommend avoiding American Roulette where possible for these reasons:

❌ Has 38 numbers (1-36 + single zero + double zero)

❌ House edge: 5.26%

That extra zero in American roulette increases your losses over time. If you spot a French roulette table (similar to European but includes “La Partage” or “En Prison” rules), go for it – it can reduce the house edge on even-money bets to 1.35%!

3. Manage Your Bankroll with Odds in Mind

Even the best odds don’t guarantee wins, so managing your money is essential. Whether you’re playing at the best roulette or blackjack betting sites, it’s simply crucial.

For example, you bring £100 to the table. Betting £1–£5 per spin on even-money bets and taking into account your previous bet, this gives you 20–100 spins worth of entertainment, keeping the experience fun and strategic.

Bankroll Tips:

Conclusion

Grasping roulette odds is key for anyone in the UK looking to enjoy the game sensibly. Understanding the likelihoods behind each wager helps players make smarter decisions, manage their budget wisely, and get the most out of their experience.

Keep in mind, roulette is a game of luck, and no strategy can promise consistent wins. Treat it as a bit of entertainment, focusing on the thrill and enjoyment it brings. By staying within your means and making careful choices, you can ensure your time at the roulette table stays fun, relaxed, and worry-free.

FAQ

Resources

1. https://www.gamblingcommission.gov.uk/
2. https://www.legislation.gov.uk/ukdsi/2025/9780348267211