Roulette RTP Explained – Everything You Need to Know

RTP Calculation in Roulette

The RTP can never be 100% in any game, because otherwise the casino would not be able to make a profit on your bets. The theoretical maximum RTP can be 99.9% - even then, the casino will still be able to make a profit (house edge) of 0.01% on each bet. Therefore, it is also possible to define and calculate the RTP as the difference between the house edge and 100%. So, the formula is:

$\mathrm{RTP}=100\%-\mathrm{house\; edge}$

Of course, in order to use this formula, it is necessary to calculate the house edge first. For this, the following formula is used:

$\mathrm{House\; Edge}=\left|\frac{(-\mathrm{bet\; amount}\times \mathrm{odds\; of\; loss})+(\mathrm{bet\; payout}\times \mathrm{bet\; amount}\times \mathrm{odds\; of\; win})}{\mathrm{Bet\; Amount}}\right|\times 100\%$

Therefore, it is possible to write the RTP formula as follows:

$\mathrm{RTP}=100\%-\left(\right|\frac{(-\mathrm{bet\; amount}\times \mathrm{odds\; of\; loss})+(\mathrm{bet\; payout}\times \mathrm{bet\; amount}\times \mathrm{odds\; of\; win})}{\mathrm{Bet\; Amount}}|\times 100\%)$

Let's give you a practical example to make it easier to understand all this. In this example, we will assume that you bet 5 ZAR on a dozen bet in a single-zero roulette game. A dozen is a bet that covers 12 numbers and pays 2 to 1. There are 37 numbers in total in single-zero roulette. Therefore, the odds of winning are 12/37, and the odds of losing are 25/37. Let’s put all this into the formula:

$\mathrm{RTP}=100\%-\left(\right|\frac{(-5\times 25/37)+(2\times 5\times 12/37)}{5}|\times 100\%)=100\%\left(\right|\frac{(-3.3783)+(-3.2432)}{5}|\times 100\%)$

$\mathrm{RTP}=100\%-\left(\right|-0.027|\times 100\%)=97.3\%$

This value is fixed: no matter which bet you choose and no matter how much money you bet on that bet, the result of the formula will always be 97.30%. For example, let's say you bet 15 ZAR on a split bet in single-zero roulette. This bet pays 17 to 1 and covers only 2 numbers. The odds of winning are 2/37, and the odds of losing are 35/37. Therefore:

$\mathrm{RTP}=100\%-\left(\right|\frac{(-15\times 35/37)+(17\times 15\times 2/37)}{15}|\times 100\%)=100\%-\left(\right|\frac{(-14.189)+\left(13.783\right)}{15}|\times 100\%)$

$\mathrm{RTP}=100\%-\left(\right|-0.027|\times 100\%)=97.3\%$

As you can see, the house edge has not changed: just like RTP, it is a fixed value. For the same reason, the RTP will still be 97.30%. So as long as you know the house edge, it's easy to calculate the RTP of any game (or roulette variant). As a final example, let's use US roulette with double zeros and imagine that you place a street bet of 10 ZAR. This bet covers 3 numbers and pays 11 to 1. You have a 3/38 chance of winning and a 35/38 chance of losing (note that this variant has 38 numbers in total, not 37).

$\mathrm{RTP}=100\%-\left(\right|\frac{(-10\times 35/38)+(11\times 10\times 3/38)}{10}|\times 100\%)=100\%-\left(\right|\frac{(-9.2105)+\left(8.6842\right)}{10}|\times 100\%)$

$\mathrm{RTP}=100\%-\left(\right|-0.0526|\times 100\%)=94.74\%$

You can find the RTP and house edge values for the basic variants of roulette in almost every source, but it is still important to learn how they are calculated, because some games have their own special exceptions, as we will discuss below.

Exceptions & Special Rules for Roulette RTP

Basket Bet Has the Lowest RTP

The basket bet is only available in the US variant, pays 6 to 1, and covers five numbers (0, 00, 1, 2, 3). However, its RTP is very low because its house edge is very high. For example, assuming you place a bet of 5 ZAR:

$\mathrm{RTP}=100\%-\left(\right|\frac{(-5\times 33/38)+(6\times 5\times 5/38)}{5}|\times 100\%)=100\%-\left(\right|\frac{(-4.3421)+\left(3.9473\right)}{5}|\times 100\%)$

$\mathrm{RTP}=100\%-\left(\right|-0.0789|\times 100\%)=92.11\%$

Straight Bets in Multiplier Roulette Are Subject to Special Rules

Games that pay multipliers (usually live roulette games) have a bonus round, which is triggered by straight bets only. Random numbers are chosen after players place their bets: if you bet on one of them and win, instead of the usual 35x, you will be eligible to participate in a bonus round where you can win multipliers, which can be as high as 10,000x.

But if your straight bet wins but is not chosen as a lucky number, you will get a lower payout instead of the usual 35x - this can be as low as 19 to 1. This, in turn, naturally affects the RTP percentage. For example, in Evolution Gaming's famous Lightning Roulette, the bonus round pays up to 500x, but regular straight bets pay 29 to 1. Assuming you bet 10 ZAR, this affects the RTP as follows:

$\mathrm{RTP}=100\%-\left(\right|\frac{(-10\times 36/37)+(29\times 10\times 1/37)}{10}|\times 100\%)=100\%-\left(\right|\frac{(-9.7297)+\left(7.8378\right)}{10}|\times 100\%)$

$\mathrm{RTP}=100\%-\left(\right|-1.8919|\times 100\%)=81.09\%$

Roulette games with multiplier payouts or bonus rounds usually have a lower RTP than standard versions. So don’t expect the same return rates listed at the start for regular roulette games.

French Roulette Has the Highest RTP

French roulette offers the highest return-to-player (RTP) percentage for even-money bets. This is due to the La Partage rule. This rule are triggered when the player places an even-money bet and loses due to the result being 0. The player is either refunded half of their bet or can repeat the same bet in the next round. In the long run, this leads to an increase in the money returned to the player, a decrease in the house edge, and an increase in the RTP. For example, let's say you place a 10 ZAR bet on RED:

$\mathrm{RTP}=100\%-\left(\right|\frac{(-10\times 18/37)+(1\times 10\times 18/37)+(-10/2\times 1/37)}{10}|\times 100\%)=100\%-\left(\right|\frac{(-4.8648)+\left(4.8648\right)+(-0.1351)}{10}|\times 100\%)$

$\mathrm{RTP}=100\%-\left(\right|0.0135|\times 100\%)=98.65\%$

This only applies to even money bets. Other types follow the same RTP as single-zero European roulette. Want to try French roulette? Start with one of these popular picks found on many casino sites: Playtech’s Live French Roulette, Evolution Gaming’s Auto Roulette La Partage, or French Roulette Gold. These versions offer a solid experience, especially for new players. They're easy to find, fun to play, and often come with the La Partage rule, which offers better odds.