Probability Calculator
About Probability Calculator
The Probability Calculator helps you find the likelihood of an event or combination of events happening. It’s a powerful tool for students, statisticians, and anyone learning probability concepts like independent, dependent, and mutually exclusive events.
Common Probability Formulas›
For a single event: P(A) = Favorable Outcomes ÷ Total Outcomes For two independent events: P(A ∩ B) = P(A) × P(B) For either event: P(A ∪ B) = P(A) + P(B) − P(A ∩ B)
These formulas help determine the chance of one or more events occurring. The probability value always lies between 0 and 1, or 0% to 100%.
Example:
Input: Find the probability of drawing a red card from a deck of 52 cards.
Output: There are 26 red cards, so P(A) = 26 ÷ 52 = 0.5 or 50%.
Steps to Use:
- Choose the type of probability (single, joint, or conditional).
- Enter the number of favorable outcomes.
- Enter the total number of outcomes.
- Click 'Calculate' to get the probability value.
Frequently Asked Questions
What is probability?›
Probability measures how likely an event is to happen. It ranges from 0 (impossible) to 1 (certain) or 0% to 100%.
How do I calculate probability manually?›
Divide the number of favorable outcomes by the total number of outcomes. Example: rolling a 6 on a die = 1 ÷ 6 ≈ 0.1667 or 16.67%.
What’s the difference between independent and dependent events?›
Independent events do not affect each other (e.g., coin tosses). Dependent events influence the next event (e.g., drawing cards without replacement).
Can I use this calculator for conditional probability?›
Yes. The calculator supports advanced formulas like P(A|B) = P(A ∩ B) ÷ P(B) for conditional events.
Where is probability used in real life?›
It’s used in risk analysis, weather forecasting, games, business predictions, and data science modeling.