Single-Zero and Double-Zero Roulette Odds Compared

Roulette odds begin with the wheel’s layout, particularly the number of zero pockets. A single-zero wheel contains 37 pockets, while a double-zero wheel contains 38. That one additional pocket changes the probability of many winning outcomes without changing the advertised payouts on standard roulette bets.

This comparison affects both European and French roulette, which normally use one zero, and American roulette, which uses two. It also matters to Australian players choosing between tables in land-based casinos and roulette games offered by licensed online operators.

Wheel pockets and winning probabilities

A European or French roulette wheel contains the number zero and the numbers 1 through 36. An American roulette wheel contains both zero and double zero alongside those same numbered pockets. The coloured red and black pockets cover 18 numbers each on either format.

When betting on one number, the winning probability is 1 in 37 on a single-zero wheel and 1 in 38 on a double-zero wheel. A payout of 35 to 1 is normally offered in both cases, so the return is the same but the chance of receiving it differs.

This distinction also applies to other inside bets. A split covers two numbers, a street covers three and a corner covers four. Their payout odds may match across wheel formats, while a double-zero wheel adds another losing outcome to the calculation.

House edge and expected value

The standard house edge is approximately 2.70% on a single-zero wheel and 5.26% on a double-zero wheel. These figures represent the casino’s theoretical advantage over a large volume of play, rather than a guaranteed loss during any particular session.

For even-money wagers such as red, black, odd or even, a single-zero wheel has 18 winning pockets and 19 losing pockets. A double-zero wheel has 18 winning pockets and 20 losing pockets. The larger loss side on the American layout creates its higher expected house edge.

Promotional offers do not change these underlying probabilities. An explanation of sticky bonus mechanics shows how bonus conditions can affect available play, while the mathematical edge remains attached to the roulette wheel itself.

Inside bets, outside bets and payouts

Roulette payout odds describe the profit returned for a winning wager, while winning probability describes how often that wager succeeds. Keeping those concepts separate makes comparisons easier, particularly when both wheel layouts offer the same 35-to-1 straight-up payout.

Outside bets generally cover more numbers. A column or dozen bet covers 12 numbers and pays 2 to 1. An even-money wager covers 18 numbers and pays 1 to 1. Their hit rates are slightly lower on a double-zero wheel because the two zero pockets are additional losses.

Long-run return follows the same pattern. A standard single-zero game returns about 97.30% of wagered funds, compared with approximately 94.74% on a double-zero game. The same metric is used elsewhere, as RTP in slot selection explains, although slot games can have different payout structures and volatility characteristics.

Roulette variants and rule differences

European roulette normally refers to a single-zero wheel, while French roulette also has one zero but may offer special rules. Under French La Partage or En Prison rules, an even-money wager can be split with the player or returned when zero occurs. These rules reduce the effective edge on the affected wagers to about 1.35%.

A double-zero wheel can include additional bets such as five-number bets, but its standard house edge remains higher. Its extra pocket means that the loss rate is greater on ordinary inside and outside wagers even when the displayed payout schedule appears generous.

Betting systems cannot alter the probabilities recorded by the wheel. A progression such as Martingale changes stake patterns and may produce occasional larger returns, but it does not remove the house edge and can leave a player with substantial losses after a sequence of unsuccessful wagers.

The Australian casino and legal context

Australia’s major land-based casino markets include Sydney, Melbourne, Brisbane and Perth. Roulette is generally available at larger casino venues, where it sits alongside blackjack, baccarat and table games such as three-card poker. Pokies remain more common in pubs and social clubs, so roulette is usually associated with a dedicated casino visit or an online casino catalogue.

Players using offshore online casinos should check the operator’s Australian licensing status and the game’s rules. The federal Interactive Gambling Act 2001 governs interactive gambling services, while state and territory authorities regulate land-based casinos and apply their own venue requirements. Minimum ages, access conditions and responsible gambling measures can therefore vary by location.

Currency does not alter the mathematics. A hypothetical A$100 turnover produces an expected house loss of about A$2.70 on a standard single-zero wheel and A$5.26 on a standard double-zero wheel. Recreational players’ gambling winnings are generally not treated as taxable income in Australia, although professional gambling activity can attract different taxation treatment.

What to remember when choosing a roulette table

The first check should be the wheel layout rather than the size of the displayed payouts. A single-zero European or French wheel gives a number wager a probability of 1 in 37, while a double-zero American wheel gives it 1 in 38. The same reasoning applies to most other standard bets.

Rules should also be compared carefully. A French table with a favourable zero rule may offer better value on even-money wagers than an ordinary single-zero table. A double-zero game can still suit a particular betting approach, but its higher standard edge must be considered against its minimum stakes, maximum limits and available side bets.

Players who also compare roulette with other table games may find single and multi-deck blackjack informative because blackjack probabilities change with the number of decks rather than through zero pockets. Roulette, by contrast, has a fixed mathematical disadvantage determined mainly by its wheel and rules. The key number to remember is 2.70% on a standard single-zero wheel versus 5.26% on a standard double-zero wheel; the extra pocket changes the mathematics before any strategy enters the game.