Created By : Vaibhavi Kumari
Reviewed By : Phani Ponnapalli
Last Updated : Apr 03, 2023

Find out the winning probability in online roulette game by using the Roulette Probability Calculator over here. Simply enter the parameters like probability of an event P(e), number of trails or spins n, number of times our bet wins x, P(b) is the probability of our bet B winning in one spin and click on the calculate button to determine unknown parameters.

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Roulette Probability Formula

The Roulette Wheel has 37 equal sized spaces. This is the case in a European Roulette and it differs from other roulettes. Usually we can use a factorial to determine in how many different ways we can arrange the roulette in practical cases. There are trillions of different arrangements for all the 37 roulette numbers. This may sound complex so we will tell you about the Roulette Probability Equation for calculating the roulette event or outcome.

The probability P(e) of the event E is given by P(e) = [ Bet b appearing x times in n spins ] = (n!/(x!(n-x)!)) P(b)x (1-P(b))n-x . To better understand this equation you should know about binomial distribution as it is the base of roulette probabilities.

Roulette Probability Problems

Question 1: Calculate the roulette probability of 1 Number along with the expected return on your $400.00 bet?


Probability of 1 Number = Total Spaces of 1 Number/Total Spaces

Probability of 1 Number = 1 Total Spaces of 1 Number/ 38 Total Spaces

Probability of 1 Number = 1/38

Success Percentage of 1 Number = Probability of 1 Number x 100%

Success Percentage of 1 Number = 1/38 x 100%

Success Percentage of 1 Number = 2.63%

Understand the difficult concepts too easily taking the help of the online tools available at and clarify your doubts during homework or assignments. You can also use roulette percentage calculator.

FAQs on Roulette Probability Calculator

1. Which Roulette Number hits most?

If you ask any player the most popular one that hits the most in roulette game is 17.

2. What is the luckiest number in roulette?

The number 7 is the most common number that people like to bet on and consider it to be lucky.

3. How do you predict roulette number probability using a calculator?

Roulette prediction calculator, and roulette number calculator. All you have to do is enter the inputs needed and tap on the calculate button to avail resultant roulette probability in a matter of seconds.