Probability Calculator

Calculate probabilities for events with accuracy using our simple tool.

Probability of A: P(A)

Probability of B: P(B)

Probability of

Event A Probability

Repeat Times

Event B Probability

Repeat Times

Mean: (µ)

Standard Deviation (σ)

Left Bound (Lb)

For negative infinite, use -Infinity

Right Bound (Rb)

For positive infinite, use Infinity

There was an error with your calculation.

Result
Probability of A NOT occuring: P(A')	0.5
Probability of B NOT occuring: P(B')	0.6
Probability of A and B both occuring: P(A∩B)	0.2
Probability that A or B or both occur: P(A∪B)	0.7
Probability that A or B occurs but NOT both: P(AΔB)	0.5
Probability of neither A nor B occuring: P((A∪B)')	0.3
Probability of A occuring but NOT B:	0.3
Probability of B occuring but NOT A:	0.2

Probability

Probability of A: P(A) = 0.5

Probability of B: P(B) = 0.4

Probability of A NOT occuring: P(A') = 1 - P(A) = 0.5

Probability of B NOT occuring: P(B') = 1 - P(B) = 0.6

Probability of A and B both occuring: P(A∩B) = P(A) × P(B) = 0.2

Probability that A or B or both occur: P(A∪B) = P(A) + P(B) - P(A∩B) = 0.7

Probability that A or B occurs but NOT both: P(AΔB) = P(A) + P(B) - 2P(A∩B) = 0.5

Probability of neither A nor B occuring: P((A∪B)') = 1 - P(A∪B) = 0.3

Probability of A occuring but NOT B: P(A) × (1 - P(B)) = 0.3

Probability of B occuring but NOT A: (1 - P(A)) × P(B) = 0.2

Probability

Probability of A occuring 5 time(s) = 0.6⁵ = 0.07776

Probability of A NOT occuring = (1-0.6)⁵ = 0.01024

Probability of A occuring = 1-(1-0.6)⁵ = 0.98976

Probability of B occuring 3 time(s) = 0.3³ = 0.027

Probability of B NOT occuring = (1-0.3)³ = 0.343

Probability of B occuring = 1-(1-0.3)³ = 0.657

Probability of A occuring 5 time(s) and B occuring 3 time(s) = 0.6⁵ × 0.3³ = 0.00209952

Probability of neither A nor B occuring = (1-0.6)⁵ × (1-0.3)³ = 0.00351232

Probability of both A and B occuring = (1-(1-0.6)⁵) × (1-(1-0.3)³) = 0.65027232

Probability of A occuring 5 times but not B = 0.6⁵ × (1-0.3)³ = 0.02667168

Probability of B occuring 3 times but not A = (1-0.6)⁵ × 0.3³ = 2.7648e-4

Probability of A occuring but not B = (1-(1-0.6)⁵) × (1-0.3)³ = 0.33948768

Probability of B occuring but not A = (1-0.6)⁵ × (1-(1-0.3)³) = 0.00672768

Probability

The probability between -1 and 1 is 0.68268

The probability outside of -1 and 1 is 0.31732

The probability of -1 or less (≤-1) is 0.15866

The probability of 1 or more (≥1) is 0.15866

CONFIDENCE INTERVALS TABLE
CONFIDENCE	RANGE	N
0.6828	-1.00000 – 1.00000	1
0.8	-1.28155 – 1.28155	1.281551565545
0.9	-1.64485 – 1.64485	1.644853626951
0.95	-1.95996 – 1.95996	1.959963984540
0.98	-2.32635 – 2.32635	2.326347874041
0.99	-2.57583 – 2.57583	2.575829303549
0.995	-2.80703 – 2.80703	2.807033768344
0.998	-3.09023 – 3.09023	3.090232306168
0.999	-3.29053 – 3.29053	3.290526731492
0.9999	-3.89059 – 3.89059	3.890591886413
0.99999	-4.41717 – 4.41717	4.417173413469

What is an Online Probability Calculator?

An Online Probability Calculator is a tool used to calculate the likelihood of an event occurring, based on the principles of probability. It provides quick and accurate computations for a variety of probability-related scenarios, including single-event probability, combined events, conditional probabilities, and independent events.

Probability is expressed as a value between 0 and 1, where:

$0$ : The event is impossible.
$1$ : The event is certain.

How to Use an Online Probability Calculator?

Access the Tool: Open the probability calculator in your browser.
Select the Scenario: Choose the type of probability calculation, such as:
- Single event.
- Multiple independent events.
- Conditional probability.
Input Values: Provide the necessary values, such as:
- Total outcomes ( $n$ ).
- Favorable outcomes ( $x$ ).
- Probability of individual events for combined probabilities.
Click “Calculate” or “Compute”: The calculator will provide the probability in decimal or percentage form.
Interpret the Result: Use the output to understand the likelihood of the event.

Frequently Asked Questions-

What types of probability can this calculator compute?
Most online probability calculators can handle:
- Basic single-event probability.
- Probability of multiple events (independent or dependent).
- Conditional probability.
- Combined events (e.g., "AND" or "OR" probabilities).
How is probability calculated?
Probability is calculated using the formula:
$P(E) = \frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}}$
Can this calculator handle conditional probability?
Yes, many calculators include an option for conditional probability, which is calculated as:
$P(A|B) = \frac{P(A \cap B)}{P(B)}$
What is the difference between independent and dependent events?
- Independent Events: The occurrence of one event does not affect the other.
- Dependent Events: The occurrence of one event affects the probability of the other.
What are some real-world applications of probability?
Probability is widely used in:
- Risk assessment.
- Weather forecasting.
- Gambling and gaming.
- Business decision-making.
- Predictive modeling in statistics.