What is Probability?
Probability measures the likelihood of an event to happen and when the event will happen. It also checks the position of a number. Probability with number 0 is described as impossibility of an event and 1 is described as certainty.
Probability Formula
The probability formula is defined as the number of favorable outcomes divided by the total number of outcomes.
$$\text{P(A)}=\frac{\text{Number of favorable Outcome}}{\text{Total Number of Favorable Outcomes}}$$
P(A) represents the probability of an event, n(E) represents number of favorable outcomes and n(S) represents total number of events. Probability formula is also written as
$$\text{P(A)}\;=\;\frac{\text{n(E)}}{\text{n(S)}}$$
Types of Probability
The probability has 3 major types which includes
 Classical
 Relative Frequency Definition
 Subjective Probability
Probability Rules
There are 2 major probability rules which include
 Addition Rule
 Multiplication Rule
Addition Rule in Probability
If there is job 1 in P ways and job 2 in q ways and both are related, we can do only 1 job at given time in p+q ways.
Multiplication Rule in Probability
If there is job 1 in P ways and job 2 in q ways and both are not related, we do both jobs at given time in p*q ways.
Can the Probability be negative?
The probability value of an outcome can never be negative. The probability value always remains postitive. For unobservable events or conditional probabilities, quasiprobability can allow a negative probability for distribution only.
The probability also helps us understanding how to find expected value by using expected number calculator.
How to find Probability?
Probability is expressed between 0 and 1. 1 is examined as accurate (True) and 0 is taken as incorrect (False). Higher Probability of event assures that this event will occur.
Main functions of Probability
There are different probability functions which we need to know while calculating the probability. These functions are
 Probability of A occurring given times
 Probability of A NOT occurring
 Probability of A occurring
 Probability of B occurring given times
 Probability of B NOT occurring
 Probability of B occurring
 Probability of A occurring given times and B occurring given times
 Probability of neither A nor B occurring
 Probability of both A and B
 Probability of A occurring given times but not B
 Probability of B occurring given times but not A
 Probability of A occurring but not B
 Probability of B occurring but not A
If set of possibilities are large and only few results are successful, then the probability of the outcome is tiny like P(B)=0.00001. It's always suitable to use the standard deviation formula calculator for reducig your answer deviation from true value.
What is Probability Calculator?
Probability Calculator is a risk analysis tool which is available online. It is designed for finding the probability for single and multiple events.
Probability Calculator helps to examine the relationships of likelihood within two different events and completes the calculations without any error. If you are looking for how to calculate probability? our probability distribution calculator is the best option for you.
Benefits of using Probability Calculator
Probability Calculator allows to calculate probability of single and multiple events easily. For example, if event A and B has the chances of 50% each, what are possible chances of happenings?
This Calculator provides 6 research goals, plus 7 more when you enter its advance level. This calculator saves a lot of time as long as one knows how to find the probability of separate events.
Problems handled by Probability Calculator
 Find P(A), given P(A')
 Find P(A'), given P(A)
 Find P(A), given P(B), P(A ∩ B), and P(A ∪ B)
 Find P(A), given P( BA ) and P(A ∩ B)
 Find P(A'), given P(B), P( BA ) and P(A ∪ B)
 Find P(A'), given P(B), P(A ∩ B), and P(A ∪ B)
 Find P( BA ), given P(A) or P(A'), P(B), and P(A ∪ B)
 Find P( BA ), given P(A) or P(A'), and P(A ∩ B)
 Find P(A ∪ B), given P(A) or P(A'), P(B), and P(A ∩ B)
 Find P(A ∩ B), given P(A) or P(A'), P(B), and P(A ∪ B)
Probability calculator solves problems which are directed by three primary rules of probability including (addition rule, subtraction rule and multiplication rule).
How to use Probability Calculator?
Probability calculator is free and easy to use. You just need to follow below steps

Step #1: Define the probabilities of single or multiple events you want to calculate. Probabilities must have two separate events.
Probability of A: P(A)
and
Probability of B: P(B)

Step #2: Find the Probability of an event. When you know how to examine the likelihood relationships of separate events, select your research goals and get the required results.
To perform the task, select an option from 6 different research goals:
 Option 1: P(A') – Probability of A not occurring
 Option 2: P(B') – Probability of B not occurring
 Option 3: P(A ∩ B) – Probability of A and B both occurring
 Option 4: P(A ∪ B) – Probability that A or B or Both occurs
 Option 5: P(A △ B) – Probability that A or B occurs but NOT both
 Option 6: P((A ∪ B)') – Probability of neither A nor B occurring

Step #3: Click on the calculate button. The intersection calculator applies the analytical technique to reach the research goal and generate summary report to explain the analysis and research findings.
We hope our probability distribution calculator worked fine for you. Please provide your valuable feedback so that we can improve if it is required.
External Resources:
 Demonstration of Probability.
 Rules of probability.
 How to calculate probability?