Probability Calculator

Single Event Probability Calculator

0.85
occurs P ( A )
0.15
occurs P ( A' )

Multiple Event Probability Calculator

0.55
P ( A )
0.45
P ( A' )
0.83
P ( B )
0.18
P ( B' )




0.45
P ( A ∩ B )
0.55
P ( A | B )
0.92
P ( A ∪ B )

What Is Probability Calculator ?

Probability is the chance that the given event will occur. Use this online probability calculator to calculate the single and multiple event probability based on number of possible outcomes and events occurred.ss

Probability Calculator Formula / Calculation


  Single Event Probability Formula

Possible Outcomes = 65
Events Occured = 55

P ( A ) = Events Occured / Possible Outcomes = 55 / 65 = 0.85

P ( A' ) = 1 - P ( A ) = 1 - 0.85 = 0.15


  Multiple Event Probability Formula

Possible Outcomes = 16
Event Occurs in A = 8
Event Occurs in B = 12

P ( A ) = Event Occurs in A / Possible Outcomes = 8 / 16 = 0.5
P ( A' ) = 1 - P ( A ) = 1 - 0.5 = 0.5
P ( B ) = Event Occurs in B / Possible Outcomes = 12 / 16 = 0.75
P ( B' ) = 1 - p ( B' ) = 1 - 0.75 = 0.25
P ( A ∩ B ) = P ( A ) * P ( B ) = 0.5 * 0.75 = 0.38
P ( A ∪ B ) = P ( A ) + P ( B ) - P ( A ∩ B ) = 0.5 + 0.75 - 0.38 = 0.88
P ( A | B ) = P ( A ∩ B ) / P ( B ) = 0.38 / 0.75 = 0.50