Red or black roulette bets pay even money (1 to 1), but they are not quite a coin toss. On a single-zero wheel 18 of the 37 pockets are your colour, so you win 48.65% of the time and the house keeps a 2.70% edge; French La Partage rules cut that to 1.35%, while a double-zero wheel raises it to 5.26%.
Red and black each have 18 numbers; the green zero (and 00) is what tips the bet against you.
A colour bet pays 1 to 1 and wins 18 in 37 spins (48.65%) on a single-zero wheel or 18 in 38 (47.37%) on a double-zero wheel.
Under French La Partage, half the stake comes back on zero, cutting the edge to about 1.35%, the cheapest standard roulette bet.
Colour streaks are normal and meaningless: after five reds the next spin is still 18 in 37 to be red.
Doubling after losses (Martingale) does not change the edge and can demand stakes over £1,000 after eight losses from £5.
Pays
1 to 1 (even money)
Numbers covered
18 red or 18 black
Chance to win (single zero)
18 in 37 (48.65%)
House edge
2.70% single zero, 5.26% double zero
With La Partage
About 1.35%
How red or black roulette bets work
Betting on a colour is the simplest choice on the table. Put your chip in the red diamond or the black diamond on the edge of the layout. If the ball settles in a pocket of that colour you double your money, getting your stake back plus the same again. If it lands on the other colour or on green, you lose the chip.
It is one of the three pairs of even-money bets, along with odd or even and high or low. All of them cover 18 numbers and pay 1 to 1, and all of them are outside bets. The term even money describes the payout, not the chance, and that difference is what this page is about.
Which roulette numbers are red and which are black
On every standard wheel the red numbers are 1, 3, 5, 7, 9, 12, 14, 16, 18, 19, 21, 23, 25, 27, 30, 32, 34 and 36. The other eighteen from 1 to 36 are black. Wikipedia's roulette article (opens in a new tab) gives an easy rule: from 1 to 10 and from 19 to 28, odd numbers are red and even numbers black; from 11 to 18 and from 29 to 36 it flips, so odd numbers are black and even numbers red.
Red and black numbers on a roulette wheel
Range
Red
Black
1–10
1, 3, 5, 7, 9
2, 4, 6, 8, 10
11–18
12, 14, 16, 18
11, 13, 15, 17
19–28
19, 21, 23, 25, 27
20, 22, 24, 26, 28
29–36
30, 32, 34, 36
29, 31, 33, 35
Zero pockets
–
– (0 and 00 are green)
On the wheel itself the colours alternate red, black, red, black all the way round, broken only by the green pocket or pockets. The pattern on the layout looks irregular because the layout runs in number order while the wheel does not. Our wheel numbers page shows the full sequence for both wheel types.
Red or black odds on every type of roulette wheel
The 1 to 1 payout never changes, but the chance of winning and the edge depend on how many green pockets there are and which zero rule applies. The figures below come from pocket counts and from Wizard of Odds' roulette basics (opens in a new tab), which also gives the La Partage and En Prison results.
Colour bet odds and house edge by wheel and rule
Game
Pockets
Chance your colour wins
What happens on zero
House edge
French, La Partage
37
48.65%
Half the stake returned
About 1.35%
French, En Prison (single imprisonment)
37
48.65%
Stake held for one more spin
About 1.39%
European
37
48.65%
Stake lost
2.70%
American
38
47.37%
Stake lost on 0 or 00
5.26%
Triple zero (rare)
39
46.15%
Stake lost on 0, 00 or 000
7.69%
The same chip on the same colour can cost more than five times as much depending on the table you pick. That makes the wheel choice the single most useful decision a colour bettor can make.
Why red or black is not a 50/50 bet
If a wheel had only the numbers 1 to 36, red and black would split them evenly and an even-money payout would be perfectly fair. The zero breaks that. Run through a perfect cycle of 37 spins with £10 on red each time: 18 reds win £180, 18 blacks lose £180, and the zero loses another £10. You finish £10 down on £370 staked, which is 2.70%.
On an American wheel the same cycle takes 38 spins: £180 won, £180 lost, and £20 lost to the two green pockets. That is £20 down on £380, or 5.26%. Nothing else separates the two games for this bet. Our page on European against American roulette looks at the wider differences, and why zero is green explains where the extra pocket came from.
French rules: the cheapest way to bet on a colour
Under La Partage, when the ball lands on zero an even-money bet loses only half its stake. Rerun the 37-spin cycle with £10 on red: £180 won, £180 lost, and just £5 lost on zero. The shortfall is £5 on £370, or 1.35%, exactly half the European figure. Wizard of Odds puts the expected value at −1.351351%.
En Prison works differently: on zero your stake is held for one more spin, and if that spin wins you get the stake back without winnings. Wizard of Odds gives single imprisonment an expected value of −1.387874%, slightly worse than La Partage. Evolution's live French Roulette (opens in a new tab) uses La Partage, so losing even-money bets on zero lose only half. Check the help screen of any French table to see which rule it uses.
These rules help even-money bets only. Dozens, columns and inside bets keep the full 2.70% edge on a French table. Our French roulette guide sets out the full rules.
Colour streaks: how often red or black repeats
Results boards often show runs of one colour, and players read them as signals. They are just what random spins look like. The chance of a particular colour landing several times in a row is 18 in 37 multiplied by itself for each spin.
Chance of the same chosen colour several times in a row (single zero)
Run of one colour
Chance
About 1 in
3
11.5%
9
5
2.7%
37
7
0.64%
155
10
0.074%
1,347
Those numbers describe the whole run before it starts. Once five reds have already landed, the next spin is a fresh event with the same 18 in 37 chance of red and 18 in 37 of black. Believing black is due after a run of red is the gambler's fallacy. Over thousands of spins the colours settle close to their expected share, but that is the law of large numbers at work, not the wheel correcting itself.
Doubling up on red or black: the Martingale maths
The best-known roulette system, the Martingale, is usually played on a colour. You double your stake after every loss, so the first win recovers everything plus your opening stake. It works most of the time, which is why it is tempting, but the occasional losing run is very expensive.
Martingale on a colour starting at £5
Losses in a row
Next stake
Total lost so far
1
£10
£5
3
£40
£35
5
£160
£155
8
£1,280
£1,275
Wizard of Odds calculates the chance of losing eight even-money bets in a row on single-zero roulette at 0.4835%, about 1 in 207, on its Martingale page (opens in a new tab). That sounds rare, but over enough cycles it is likely to turn up eventually, and each time it does it wipes out the £5 profits from roughly 255 successful cycles. Table limits often stop the doubling first. The edge stays 2.70% throughout, and our betting systems guide shows why every progression fails in the same way.
What colour betting costs over a session
The edge becomes real money once you multiply it by your total stake. Here is the average cost of 50 spins at different stakes on each wheel. A single session can finish well above or below these figures, but over many sessions the averages win out.
Average cost of 50 colour bets
Stake per spin
French La Partage (1.35%)
European (2.70%)
American (5.26%)
£2
£1.35
£2.70
£5.26
£5
£3.38
£6.76
£13.16
£10
£6.76
£13.51
£26.32
£25
£16.89
£33.78
£65.79
This is the honest price of the entertainment. If £13.51 for 50 spins at £10 feels fair to you, the bet fits your budget; if it does not, a lower stake or a French table brings the cost down. Our cost per hour guide compares roulette with other games.
How to bet on red or black online
Choose a table, ideally single zero, and a French one with La Partage if you mainly bet on colours.
Set your chip value, keeping it to a stake your session budget can absorb over a long losing run.
Tap the red or black diamond on the outside of the layout.
Check the bet slip shows one colour bet and the right stake.
Confirm before the timer ends, and decide in advance how many spins you will play.
Red or black at live and RNG tables, and UK rules
Colour bets work the same way in RNG games, where certified software picks the pocket, and at live roulette tables with a physical wheel. In Lightning Roulette, red and black keep their normal 1 to 1 payout; only straight-up bets change. Some games, such as French tables, add La Partage, so read the rules panel first.
UK online slot stake limits do not apply to roulette; table limits set the minimum and maximum.
From 17 January 2025, autoplay is banned for all online casino games, live roulette included, though a re-bet button is allowed.
Non-slot games must allow at least 5 seconds per game cycle, and you cannot play several games at once.
Net spend and time spent are displayed while you play, and credit cards cannot be used to gamble.
If you need a break, GAMSTOP (opens in a new tab) blocks you from all UK-licensed gambling sites for free, and the National Gambling Helpline is on 0808 8020 133.
Where to bet on red or black roulette in the UK
The offers below are not roulette offers. Table and live games are often excluded from bonuses or count for less towards wagering, so check the terms, and check each casino's game lobby for French or European tables. 18+ and terms apply.
Casumo: 50% bonus up to £100 for new customers who opt in, first deposit minimum £20; 10x wagering within 7 days, £5 maximum bet, game, play and payment restrictions.
10bet: 100% up to £25 on the first deposit within 7 days of choosing the casino bonus; 10x wagering on slots within 3 days, maximum bonus winnings £1,000, Skrill and Neteller excluded.
Coral: bet £10 on slots, get 100 free spins (10p, selected games, accept within 48 hours, valid 7 days, no wagering on winnings); several deposit types, including PayPal, don't qualify.
Significant terms: 18+. New customers only. Opt-in required. 50% deposit bonus up to £100 on first deposit. Minimum deposit £20. 10x wagering on the bonus amount. Maximum bet or spin £5. Bonus valid for 7 days. Game, play and payment method restrictions apply. Full T&Cs apply. GamCare.org.uk
Significant terms: 18+. New UK customers only. Select the casino welcome bonus at sign-up and make your first deposit within 7 days. 100% bonus up to £25. Wager the bonus 10x on slots within 3 days. Maximum bonus winnings £1,000. Skrill and Neteller deposits do not qualify. Bonus is not redeemable. Full T&Cs apply. GamCare.org.uk
Read our 10bet reviewLicence: Blue Star Planet Limited, Gambling Commission account 43173. Offer checked 5 October 2026.
Significant terms: 18+. New players only. Offer runs 01/10/2026 to 01/02/2027. Deposit (certain types excluded) and bet £10+ on slot games to get 100 free spins (selected games, £0.10 each, 48 hrs to accept, valid 7 days). No wagering on free spin winnings. Deposits by Neteller, PayPal, Paysafe, Skrill, prepaid cards and certain debit cards do not qualify. Restrictions and T&Cs apply. GamCare.org.uk
Read our Coral reviewLicence: LC International Limited, Gambling Commission account 54743. Offer checked 5 October 2026.
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.
Frequently asked questions
What are the odds of red or black in roulette?
On a single-zero wheel your colour wins 18 times in 37, or 48.65% of spins. On an American wheel with a double zero the chance falls to 18 in 38, or 47.37%. In both cases the green pockets are why the chance is under 50%. The payout stays at 1 to 1 regardless. See our roulette odds page for how every bet compares.
Is red or black a 50/50 chance?
No, red or black is slightly worse than 50/50 because of the green zero. With 18 red, 18 black and one zero, each colour wins 48.65% of the time on a European wheel. Over a perfect 37-spin cycle at £10 a spin you would lose £10, a 2.70% edge. On a French table with La Partage half your stake returns on zero, cutting that to 1.35%. Our house edge guide explains the sums.
What happens to a red or black bet if the ball lands on zero?
On a standard European or American table, a colour bet loses in full when the ball lands on zero. On a French table using La Partage you get half your stake back, and under En Prison the stake is held for one more spin and returned without winnings if that spin wins. Check the game's help screen to see which rule applies. Our La Partage rule page explains the difference.
Is red or black the best bet in roulette?
On a French table with La Partage, red or black is one of the cheapest bets in roulette, at about 1.35%. On a plain European table it costs 2.70%, the same as every other bet there, so it is no better or worse than a dozen or a single number. It simply wins more often and pays less. Our best bet in roulette answer covers every option.
How many red numbers are on a roulette wheel?
There are 18 red numbers: 1, 3, 5, 7, 9, 12, 14, 16, 18, 19, 21, 23, 25, 27, 30, 32, 34 and 36. The other 18 numbers from 1 to 36 are black, and zero (plus double zero on American wheels) is green. On the wheel the colours alternate all the way round. Our page on how many numbers are on a roulette wheel covers each wheel type.
What is the longest streak of one colour in roulette?
There is no limit to how long a colour streak can run, because every spin is independent. The chance of one chosen colour landing ten times in a row on a single-zero wheel is about 0.074%, roughly 1 in 1,347, so long runs are rare but expected sometimes across many spins. A streak does not make the other colour more likely. Our hot and cold numbers page explains why patterns mislead.
Does the Martingale system work on red or black?
No, the Martingale does not beat the edge on red or black. Doubling after each loss usually recovers your stake plus a small profit, but a run of losses can demand huge bets: from £5, eight losses means a £1,280 ninth bet with £1,275 already lost. That run has about a 1 in 207 chance each cycle on single zero. Our Martingale system page sets out the full maths.
Can you bet on red and black at the same time?
Yes, most tables let you, but it achieves nothing useful. One colour wins and the other loses on 36 of the 37 numbers, so you break even, and on zero you lose both stakes, or half of each under La Partage. It is simply paying the house edge without any chance of winning. Our roulette myths page covers this and other popular misconceptions.
We use no tracking cookies. We store one item in your browser to remember this notice. Casino sites may set their own cookies after you follow an advert link. Cookie policy
