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Both calculators run independently — change the inputs on either side to compare results.

Birthday Paradox Calculator

Find the surprisingly high probability that at least two people in a group share a birthday. Use it to demonstrate why coincidences are far more likely than intuition suggests.

Number of People (people)

Days in Year (days)

Fill in the required fields to see your result.

Probability

Conditional Probability Calculator

Apply Bayes' theorem to find conditional probabilities, intersections, and unions of two events. Useful in medical testing, risk analysis, and machine learning evaluation.

P(A) - Probability of Event A

P(B) - Probability of Event B

P(B|A) - Probability of B given A

Calculate

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Key differences

	Birthday Paradox Calculator	Conditional Probability Calculator
Category	Probability	Probability
Inputs required	2	4
Result	Probability of Match	Probability
What it does	Find the surprisingly high probability that at least two people in a group share a birthday. Use it to demonstrate why coincidences are far more likely than intuition suggests.	Apply Bayes' theorem to find conditional probabilities, intersections, and unions of two events. Useful in medical testing, risk analysis, and machine learning evaluation.