What is the probability of two independent events?

Multiply the probabilities: P(A and B) = P(A) × P(B). For example, flipping two heads in a row: P = 1/2 × 1/2 = 1/4 = 25%.

What is the complement rule?

P(event does NOT occur) = 1 - P(event occurs). If there is a 30% chance of rain, there is a 70% chance of no rain.

What is the difference between theoretical and experimental probability?

Theoretical probability is calculated mathematically. Experimental probability is based on actual observations (number of times an event occurred / number of trials).

Probability Calculator

The Probability Calculator computes the likelihood of an event occurring based on the number of favourable outcomes and total possible outcomes. Probability ranges from 0 (impossible) to 1 (certain), and is expressed as a fraction, decimal, or percentage. Understanding probability is essential in statistics, gambling, insurance, science, and everyday decision-making.

Favourable Outcomes

Total Possible Outcomes

How to Use This Calculator

1
Count the number of favourable outcomes (the outcomes you want).
2
Count the total number of possible outcomes.
3
Click Calculate to see the probability as a percentage.

Frequently Asked Questions

Probability = Favourable Outcomes / Total Outcomes. It measures how likely an event is. P = 0 means impossible; P = 1 (100%) means certain. Rolling a 3 on a die: P = 1/6 ≈ 16.67%.

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