Probability Calculator
Calculate probability for single events, combined events, and permutations/combinations.
100% Client-Side
What is Probability Calculator?
A probability calculator helps you determine the likelihood of events occurring, whether single events, combined events, or conditional scenarios. It covers basic probability, permutations, combinations, and Bayesian probability -- useful in statistics, gaming, risk assessment, and everyday decision-making.
How to Use
- Select the type of probability calculation you need
- Enter the number of favorable outcomes and total possible outcomes
- For combined events, specify whether they are independent or dependent
- Review the probability as a fraction, decimal, and percentage
Formula
P(A) = Number of favorable outcomes / Total number of outcomes
Frequently Asked Questions
- What is the difference between permutation and combination?
- Permutations count arrangements where order matters (e.g., rankings). Combinations count selections where order doesn't matter (e.g., lottery numbers).
- How do I calculate the probability of two events both happening?
- For independent events, multiply their probabilities: P(A and B) = P(A) x P(B). For dependent events, use P(A and B) = P(A) x P(B|A).
- What does a probability of 0.5 mean?
- It means there is a 50% chance of the event occurring -- like flipping a fair coin and getting heads.