The formula can be used to calculate the probability of winning all roulette bets. It turns out the probability of you winning with a straight up bet on number 16 is 2.70%. Then, we multiply the decimal number by 100 and the result is: 0.0270 x 100 = 2.70.

We divide the number of ways to win by the number of all possible outcomes and get the following: 1 / 37 = 0.0270. And indeed it is, but we want to convert it to a percentage. But before you put your money on stake, you want to figure out what the probability of number 16 coming up on the next spin of the wheel is.Ī seasoned gambler would say the probability of 16 winning is 1 to 37. You want to place a straight up bet on an individual number, number 16, for example. This makes for a total of 37 possible outcomes on any given spin of the wheel. Let us assume we are playing the European variation of the game where there are 36 numbered pockets on the wheel plus a single-zero pocket. Naturally, this principle can be applied in the game of roulette as well. Bear in mind the total number of outcomes includes both the ways to win and the possible ways to lose.

This way we get the following result: 1 / 2 = 0.50 x 100 = 50%. To convert the probability of tails coming up into a percentage, one needs to divide the first number of the fraction by the second number. In this instance, we are betting that tails will come up so the probability of this happening can be expressed as 1 out of 2, 1 to 2, 1:2 or 1 / 2. There are only two possible outcomes of a coin flip – either heads or tails will come up. Ask yourselves what is the probability of tails coming up the next time you flip the coin. The concept of probability can best be explained by giving the coin-flip as an example. So in this instance, 1 represents the number of ways to win with a straight up bet, while 37 stands for the total number of possible outcomes.

For every straight up bet, there are two possible outcomes – the player either wins or loses. In European roulette, all 37 numbers have equal chances of coming up. The second number or 37 in our example, represents the overall number of possible outcomes. When the probability is expressed as a fraction, the first number stands for the expected frequency of a given event occurring. When the concept of probability is applied to roulette, it is expressed as “1 out of 37”, for example, or is written down as 1/37, which is the same thing. In casino games like roulette, however, the term denotes the likelihood that a given number will come up. Generally speaking, the term “probability” can be defined as the likelihood that a specific event or outcome will occur.

Roulette double and single zero