RTP in Roulette – Why It Matters and How to Calculate

Calculating RTP in Different Roulette Variants

To explain this, we first need to explain what the house edge is briefly. The house edge is the opposite of the RTP and is the percentage of the casino's profit that it will make from your bets. No game pays out 100%. Otherwise, casinos would not make any revenue. There will always be a difference. The house edge determines how big this difference will be. The sum of the RTP and house edge will always be 100%. So, if we subtract 100% from the house edge of a game, the result will show what the RTP will be. We can formulate this as follows:

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

So, by learning to calculate the house edge, we can easily calculate the RTP. This is done according to the following formula:

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

So, the full RTP formula looks like this:

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

As a practical example, let's choose the DOZEN bet and assume we place a wager of RM5. This bet pays 2x and, as the name suggests, covers 12 numbers. The house edge calculation will be as follows:

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

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

You can choose any bet type and place any stake: whatever your choices, the house edge of single-zero European roulette will always be 2.70%, and the RTP will always be 97.30%. These fixed values are the basis of the game, and you cannot manipulate them in any way. We can prove this with a random bet and a different wager. For example, let's say we're playing European roulette again, we opt for the SPLIT bet and place a bet of RM15. SPLIT pays 17x and covers only two numbers.

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

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

This formula also applies to other roulette variants, but you will need to change the total number on the wheel. For example, American roulette has 38 numbers. So, when we place the LOW bet in this game, you need to calculate the chances of winning as 18/38, not 18/37. Likewise, the odds of losing should be calculated as 20/38.

At the beginning of this article, we mentioned that the RTP of American roulette is 94.74%. So, no matter which bet we choose, the result of our formula should be 94.74 in this game as well. Let's prove this with an example, and this time use a STREET bet. This is a bet that pays 11x and covers 11 numbers. Let's set the wager amount to RM10 this time.

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

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

Therefore, our formula gave the expected result: 94.74%. The result would be the same even if we chose a different bet type and used a different wager amount. However, for some bet types and game variants, there will be some exceptions to this general rule: let's take a look at them below.

Special Rules for Roulette RTP

Basket Bet: Lowest RTP

This bet covers the numbers 0, 00, 1, 2, and 3, and for the same reason, is only available in American roulette (since the 00 pocket is only available in this variant). Although it pays 6x, it unfortunately has the lowest RTP. Let's see what kind of payback ratio it offers by making a bet of RM5:

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

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

Multiplier Roulette: Volatile RTP Values

The majority of live roulette games have a “lucky numbers” mechanic. After players place their bets and before the spin starts, random numbers are selected and assigned multiplier values. If you have placed a straight bet, your bet is selected as a Lucky Number, and if you win that bet, you will get a multiplier payout.

However, winning straight bets that are not selected as a Lucky Number will also get a lower payout than usual (35x). It's even possible to find games on the market that pay as low as 19x. For example, Evolution's Lightning Roulette pays up to 500x but only 29x for regular straight bets. If you bet RM10 on this game:

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

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

Depending on how different the payout on a regular straight bet will be, the RTP value will vary, and this can be quite volatile.

French Roulette: Highest RTP

French roulette is known for having the highest RTP, but this only applies to even money bets. (For other types of bets, the RTP is the same as for European roulette.) This is because even money bets that are lost because the result is 0 are refunded half of the wager (La Partage), or you can use the same wager in the next round (En Prison). This causes the house edge for even money bets to decrease and the RTP to increase. For example, if we place a bet of RM10 on BLACK:

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

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

If you're playing this variant, make sure you only choose even money bets, as you won't benefit from the high RTP on the others. Live French Roulette (Playtech), Auto Roulette La Partage (Evolution Gaming), and French Roulette Gold are among the options we recommend you try.