Compare calculators

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

Chi-Square Test Calculator

Calculate the chi-square (χ²) test statistic and compare it against a critical value to test goodness of fit or independence. Used in research, biology, marketing, and quality control.

Observed Frequency 1

Expected Frequency 1

Observed Frequency 2

Expected Frequency 2

Fill in the required fields to see your result.

Probability

Bayes' Theorem Calculator

Compute the posterior probability P(A|B) using Bayes' theorem. Use it when you want to update a prior belief about event A after observing new evidence B — common in medical testing, spam filtering, and risk analysis.

Prior Probability P(A)

P(B|A) - Likelihood

P(B) - Evidence

Fill in the required fields to see your result.

Key differences

	Chi-Square Test Calculator	Bayes' Theorem Calculator
Category	Probability	Probability
Inputs required	4	3
Result	Chi-Square Statistic	P(A\|B) Posterior Probability
What it does	Calculate the chi-square (χ²) test statistic and compare it against a critical value to test goodness of fit or independence. Used in research, biology, marketing, and quality control.	Compute the posterior probability P(A\|B) using Bayes' theorem. Use it when you want to update a prior belief about event A after observing new evidence B — common in medical testing, spam filtering, and risk analysis.