Odd or even roulette

How odd or even roulette bets work

Every roulette layout has two boxes on its outer edge marked ODD and EVEN, sometimes IMPAIR and PAIR on French tables. A chip in the odd box backs the eighteen odd numbers from 1 to 35; a chip in the even box backs the eighteen even numbers from 2 to 36. A winner pays 1 to 1, so £10 returns £20.

It is one of three pairs of even-money bets, alongside red or black and high or low. All six are outside bets covering 18 numbers. If you are new to the game, our how to play roulette guide explains the table before you place a chip.

Is zero odd or even in roulette?

In maths, zero is an even number: it divides by two with nothing left over. In roulette, though, zero is not counted as even for this bet. It is treated as a separate green pocket that belongs to neither side, and when it lands both the odd and the even bets lose. The same goes for the double zero on American wheels. Wikipedia's summary of roulette bets (opens in a new tab) notes that, except where a table states otherwise, all of these bets lose if a 0 comes up.

That one rule is the whole reason the bet is not a fair 50/50. If zero counted as even, the even bet would win 19 times in 37 and the odd bet would carry double the cost. Instead both sides are treated equally, and both pay for the green pocket. On a French table using La Partage, a zero returns half the stake on odd or even, which halves that cost. The guide to whether you can bet on zero explains how to back the green pocket itself.

Odd or even roulette odds and payout

Wizard of Odds lists odd and even at 1 to 1 on its roulette basics page (opens in a new tab), with a 47.37% win chance on a double-zero wheel. The single-zero figure comes straight from the pocket count, 18 out of 37.

In expected value terms, each £1 on odd at a European table wins £1 with probability 18/37 and loses £1 with probability 19/37. Subtract one from the other and you get −1/37 of a pound, about −2.7p, on every pound staked. Our expected value guide shows the same formula at work in other games.

How odd and even overlap with red and black

Many players assume odd and even follow the colours, but they do not. Using the standard list of red numbers, the split comes out unevenly:

That imbalance matters only when you combine bets. Suppose you put £10 on even and £10 on red. On the 8 red even numbers both win (+£20). On the 10 red odd and 10 black even numbers one wins and one loses (£0). On the 8 black odd numbers and zero both lose (−£20). Over 37 spins that is 8 × £20 = £160 won against 9 × £20 = £180 lost: −£20 on £740 staked, or 2.70%. Swap to even plus black and the overlap grows to ten numbers, but the edge stays exactly where it was.

Odd and even on the wheel and the layout

On the layout, odd and even simply alternate number by number. On the wheel the pattern is looser: Wizard of Odds' notes on the wheel (opens in a new tab) say two odd numbers usually alternate with two even numbers. The wheel's designers spread the numbers so that no section is packed with one type, but this has no bearing on the odds. Each pocket is equally likely, so 18 odd pockets give 18 chances in 37 wherever they sit. Our wheel numbers page shows the exact order.

Odd and even also split evenly across the other outside bets. Every dozen and every column contains six odd and six even numbers, and the low half (1–18) and high half (19–36) each have nine of each. So an odd bet placed alongside a dozen bet or a column bet always overlaps in exactly six numbers.

Session swings on odd or even: the average and the range

Because odd or even wins nearly half the time, results feel balanced, yet short sessions still swing widely. For an even-money bet, the typical swing over n spins is about one stake multiplied by the square root of n. Over 100 spins that is about 10 stakes. Compare that with the average loss of 100 ÷ 37, about 2.7 stakes, and you can see that luck dominates a single session while the edge dominates a lifetime of play.

Roughly two sessions in three finish within one swing of the average. So at £5 a spin, ending 100 spins somewhere between about £36 up and £64 down is ordinary. Our guide to variance and standard deviation explains the maths, and risk of ruin shows how stake size affects how long a budget lasts.

Paroli and d'Alembert: odd or even strategy against the maths

Even-money bets attract staking systems. Two common ones work in opposite directions.

• Paroli: double your stake after each win and go back to the start after a loss or after three wins in a row. From £5, three straight wins turn £5 into £40, but the chance of three wins in a row on single zero is (18/37)³, about 11.5%. Most attempts end in a small loss. See our Paroli system page.
• d'Alembert: add one unit after a loss and take one away after a win. In Wizard of Odds' d'Alembert simulations (opens in a new tab) on single-zero even-money bets, players reached their session goal between 89.81% and 99.26% of the time, yet the expected result was negative in every case and losses matched the 2.703% edge. Our d'Alembert page has the detail.

Both systems reshape the session, more frequent small wins with rare big losses, or the reverse, but neither touches the house edge. The only decisions that change the cost are the table (French, European or American) and the stake. Our roulette betting systems overview covers every popular progression.

How to bet odd or even at an online roulette table

1. Open a roulette game and check the wheel: one green pocket (single zero) or two (double zero).
2. If the table is French, check its rules panel for La Partage or En Prison.
3. Choose your chip value.
4. Tap the ODD or EVEN box (IMPAIR or PAIR on French layouts) on the outside of the table.
5. Confirm before the betting time runs out; use re-bet if you want the same bet next spin.

Odd or even, red or black, high or low: which is best?

All three even-money pairs share the same maths. The only differences are which numbers they cover and how they overlap.

No pair is better than another. If you like the even-money bets, the useful choice is a French table with La Partage, which halves the cost on all six. You can compare these with every other roulette bet on our roulette payouts page.

Common myths about odd or even bets

• "Zero is even, so the even bet wins." Not in roulette; zero belongs to neither bet.
• "After six odds, even is due." Every spin has the same 18 in 37 chance. Our gambler's fallacy page explains why past spins don't matter.
• "Odd and even are the same as the colours." Ten odd numbers are red and eight are black, so the bets differ.
• "A long enough session evens things out in my favour." Over a long run, results drift towards the 2.70% loss, not towards break-even.

Odd or even at live and RNG tables, plus UK rules

Whether the result comes from software or a filmed wheel, odd and even pay 1 to 1 with the same edge for the wheel type. In branded games such as Lightning Roulette, even-money bets keep their standard payout. The RNG against live roulette page compares pace and table limits.

Roulette is not covered by the online slot stake limits. Since 17 January 2025, the Gambling Commission's product design standard (opens in a new tab) bans autoplay for all online casino games including live tables (re-bet buttons are allowed), sets a minimum of 5 seconds per game cycle for non-slot games, stops you playing several games at once and requires net spend and time to be shown in real time. Credit cards cannot be used to gamble, and age and identity checks come first.

If gambling stops being fun, help is free. GamCare's support services (opens in a new tab) include counselling and the National Gambling Helpline on 0808 8020 133, open 24 hours a day. Tools such as deposit limits help keep play within budget.

Where to play odd or even roulette in the UK

The offers here are not roulette offers. Table and live games are often excluded from bonuses or count for less towards wagering, so read the terms first and check each casino's game lobby for French or European tables. 18+ and terms apply.

• Casumo: 50% bonus up to £100, minimum first deposit £20, opt-in required; wager the bonus 10x within 7 days, £5 maximum bet, game, play and payment restrictions apply.
• 10bet: 100% match up to £25 for new UK customers who pick the casino bonus and deposit within 7 days; 10x wagering on slots within 3 days, maximum bonus winnings £1,000, Skrill and Neteller excluded.
• Coral: bet £10 on slots and get 100 free spins (10p each, selected games, accept within 48 hours, valid for 7 days, no wagering on winnings); Neteller, PayPal, Paysafe, Skrill, prepaid cards and certain debit cards don't qualify.

18+. Every casino game has a built-in house edge, so over time you should expect to lose what you stake. Set a budget before you play and stop when it’s gone: safer gambling tools and support. Free, confidential help: National Gambling Helpline 0808 8020 133.