Statistics Calculators

Determine if your A/B test results are statistically significant using a two-proportion z-test.

Perform a one-way analysis of variance (ANOVA) using group summary statistics to test if group means differ significantly.

Calculate posterior probability using Bayes' theorem. Given prior probability, sensitivity, and false positive rate, find the updated probability.

Calculate binomial probabilities P(X = k), P(X ≤ k), and P(X ≥ k) for a given number of trials, successes, and probability of success.

Calculate the five-number summary, IQR, fences, and detect outliers from up to 10 data values for box-and-whisker plot construction.

Calculate the chi-square test statistic and approximate p-value for a goodness-of-fit or independence test with observed and expected frequencies.

Calculate the coefficient of variation (CV) to compare relative variability between data sets with different units or means.

Calculate the probability of getting a specific number of heads (or tails) in a series of coin flips, including biased coins.

Calculate nCr (combinations) and nPr (permutations) for any values of n and r.

Calculate confidence intervals for a population mean using sample statistics. Supports 90%, 95%, and 99% confidence levels.

Calculate the Pearson correlation coefficient (r) and R-squared from summary statistics to measure the linear relationship between two variables.

Calculate the covariance between two variables to measure how they change together, along with the correlation coefficient and direction of association.

Look up critical values for z, t, chi-square, and F distributions at common significance levels.

Calculate mean, median, mode, range, variance, standard deviation, and more from up to 10 data values.

Calculate the probability of rolling a specific sum with multiple dice. Supports 4, 6, 8, 10, 12, and 20-sided dice.

Calculate Cohen's d effect size to measure the practical significance of the difference between two group means.

Calculate the expected value (mean) of a discrete random variable from up to 6 outcome-probability pairs.

Calculate probabilities for the exponential distribution, modeling time between events. Find P(X < x), P(X > x), and the PDF value.

Model exponential growth or decay. Calculate final value, doubling/halving time, and period-by-period values.

Calculate the F-statistic and approximate p-value for comparing two sample variances using the F-test.

Perform Fisher's exact test on a 2x2 contingency table to test for association between two categorical variables.

Calculate the five-number summary (min, Q1, median, Q3, max) from a normal distribution using mean and standard deviation.

Group data into frequency classes. Calculate class width, boundaries, and expected frequencies for histogram construction.

Calculate the geometric mean of a set of positive numbers. Useful for growth rates, financial returns, and ratios.

Calculate the harmonic mean of positive numbers. Ideal for averaging rates, speeds, and ratios where the denominator varies.

Calculate hypergeometric probabilities for sampling without replacement. Find the probability of drawing exactly k successes.

Set up and evaluate a hypothesis test. Determine the test statistic, critical value, and conclusion for one-sample z-tests and t-tests.

Calculate the interquartile range (IQR), outlier fences, and spread measures from Q1 and Q3 values or from mean and standard deviation.