What's the difference between combinations and permutations?

Combinations count selections where order doesn't matter (choosing 3 people from 10 for a committee). Permutations count arrangements where order matters (choosing 1st, 2nd, 3rd place from 10 runners).

How do I calculate the probability of multiple events?

For independent events, multiply probabilities: P(A and B) = P(A) × P(B). For mutually exclusive events, add probabilities: P(A or B) = P(A) + P(B). For dependent events, use conditional probability.

What does a probability of 0.25 mean?

A probability of 0.25 (or 25%) means the event has a 1 in 4 chance of occurring. If you repeated the experiment many times, you'd expect the event to happen about 25% of the time.

Can probability be greater than 1?

No, probability cannot exceed 1 (or 100%). A probability of 1 means the event is certain to occur. If you calculate a value greater than 1, check your calculation for errors.

Probability Calculator – Basic & Advanced Probability

Calculate basic probability, combinations, permutations, and complex probability scenarios. Essential for statistics, gaming, and decision analysis.

Probability Calculator – Basic & Advanced Probability

Calculate basic probability, combinations, permutations, and complex probability scenarios. Essential for statistics, gaming, and decision analysis.

Calculation Type*

Type of probability calculation

Favorable Outcomes

Number of favorable outcomes (for basic probability)

Total Outcomes

Total number of possible outcomes

n (total items)

Total number of items to choose from

r (items chosen)

Number of items being chosen

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Understanding Probability

Probability measures the likelihood of an event occurring, expressed as a number between 0 (impossible) and 1 (certain), or as a percentage between 0% and 100%.

Types of Probability Calculations

Different probability calculations:

Basic Probability: P(event) = favorable outcomes / total outcomes
Combinations: Number of ways to choose r items from n items (order doesn't matter)
Permutations: Number of ways to arrange r items from n items (order matters)
Conditional Probability: Probability of event A given event B has occurred
Independent Events: P(A and B) = P(A) × P(B)

How to Use This Calculator

Follow these simple steps to get accurate results:

Enter your calculation type
Enter your favorable outcomes
Enter your total outcomes
Enter your n (total items)
Enter your r (items chosen)
Click the "Calculate" button to see your results
Review the detailed breakdown and explanation

Why Use Our Probability Calculator – Basic & Advanced Probability?

100% free and no registration required
Instant, accurate calculations with professional formulas
Mobile-friendly design that works on any device
Privacy-focused - your data never leaves your browser
Educational content to help you understand the results

Frequently Asked Questions

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