Probability Calculator

Calculate probabilities, combinations (nCr), permutations (nPr), factorials, coin flip and dice odds, and Bayes' theorem. 100% client-side.

10.5Kuses
8.5/10(450)

Enter favorable outcomes and total outcomes.

How to Use the Probability Calculator

  1. Select a calculation mode: Basic, Combinatorics, Coin/Dice, or Bayes.
  2. Enter the required values for your calculation.
  3. Results appear instantly with formulas and explanations.

Calculators Included

  • Basic probability: favorable events / total outcomes
  • Combinations (nCr): choosing r items from n without order
  • Permutations (nPr): arranging r items from n with order
  • Factorials: n!
  • Coin flip probability for exact number of heads
  • Dice roll probability for target values
  • Bayes' theorem: posterior probability calculation

Recommended Products

Ad

Affiliate Disclosure: As an Amazon Associate, ToolBird earns from qualifying purchases. Links above are affiliate links — if you buy through them, we may earn a small commission at no extra cost to you.

Disclaimer: This tool is provided as-is for informational and educational purposes only.

ToolBird Assistant

Find the right tool instantly

Hey! I'm ToolBird Assistant. Tell me what you need and I'll find the right tool for you.