Probability Calculator

Probability Calculator – Odds, Percentage & Binomial

Inputs

Example: hearts in a deck → favorable = 13, total = 52
Leave trials blank for single-event probability only. For binomial, set n and choose a k mode.

Results

Enter inputs to see probability and odds. Add trials to compute binomial results.
Notes: P = favorable / total. Odds for = P : (1−P). Binomial: P(X=k) = C(n,k) p^k (1−p)^(n−k).

Probability Calculator – Find Odds, Chances & Percentages

This guide explains how to calculate probabilities with formulas, step-by-step examples, and real-world applications.

What is Probability?

In mathematics, probability measures how likely an event is to occur. It ranges from 0 (impossible) to 1 (certain) and can be expressed as a fraction, decimal, or percentage.

Basic Probability Formula

P(E) = favourable outcomes / total outcomes

Example: For a fair coin: P(Heads) = 1/2 = 0.5 = 50%

Worked Examples

  • Die roll: P(4) = 1/6 ≈ 16.7%
  • Card draw: P(Heart) = 13/52 = 25%
  • Two heads in a row: (1/2) × (1/2) = 1/4 = 25%

Real-World Applications

  • Games of chance: cards, dice, lottery.
  • Science & statistics: experiments, testing, sampling.
  • Finance: risk management, insurance.
  • Everyday life: weather, sports, medical diagnostics.

FAQ

Probability vs odds? Probability measures chance of success; odds compare success to failure.

What about multiple trials? Multiply the probability of each independent trial or use the binomial formula.

How do percentages work? Convert percentages to decimals (e.g., 25% = 0.25).

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