Created By : Vaibhavi Kumari
Reviewed By : Rajashekhar Valipishetty
Last Updated : Mar 23, 2023

You can make use of this geometric probability calculator to check the probability of a specified number of trails. For that you need to do is just enter the input values and tap the calculate button to get the answer instantaneously.

The success probability
Number of trials

What Is Geometric Probability ?

Geometric probability is used to describe the probability for a specified number of trails that takes place before the first success occurs. This probability is mainly built on the series of independent trails with two events. We will look into the formula that takes place to determine the geometric probability.

P(X=x) = (1-p)x-1* p

Where, x=1,2,3....

x = integer and there is no max values for x.

p = probability of success for single trail.

X = Random Variable.

How to Calculate the Geometric Probability ?

Have a look at these guidelines that are shown below to determine the probability of failures before the first success.

  • First and foremost thing we need to do is write all the needed values in the problem.
  • Apply, the formula. P(X=x) = (1-p)x-1* p
  • Finally, see the desired answer.

Example Question for Geometric Probability

Example Question: If you flip a coin until it turns up the first tail. Find the geometric probability where it takes three flips to get the first tail?


Given data is x=3, p=0.5

As we know the formula, P(X=x) = (1-p)x-1* p

Substitute the values in the given formula and the equation becomes,

P(X=3) = (1-0.5)2 *(0.5)

P(X=3) = (0.25)(0.5) = 0.125

Thus, the probability of three flips to get the first tail is 0.125.

Similiar to geometric probability we have many other probability calculators that are available on to complete your work very easily.

FAQs on Geometric Probability Calculator

1. What is Geometric Probability?

Geometric probability is used to determine the probability of specified failures before getting the first success.

2. How do you find the geometric probability?

Finding the geometric probability is very easy, just use the formula to calculate it, i.e. P(X=x) = (1-p)x-1* p

3. What does x and p means in the geometric probability formula?

In geometric probability formula, x is the integer (or) whole number and p is the probability of success.

4. How to use geometric probability calculator?

All you need to do is enter the input values in the input fields and hit the calculate button to get the resultant value in seconds.