Statistics & Probability calculators

Summarise data clearly. Find the mean, median, mode and range of a list of numbers, and measure how spread out the data is with the standard deviation and variance for a sample or a population. Paste values separated by commas, spaces or new lines, and see the sorted data and every step.

Mean, Median & Mode Calculator

Find the mean, median, mode and range of a data set.

Standard Deviation Calculator

Calculate the standard deviation and variance of a data set, for a sample or a population, with the deviations table and every step shown.

Normal Distribution Calculator

Find normal probabilities P(X < a), P(X > a) or P(a < X < b) from the mean and standard deviation, with z-scores and a shaded bell curve.

Binomial Distribution Calculator

Calculate binomial probabilities for exactly, at most or at least k successes in n trials.

Permutation & Combination Calculator

Calculate permutations (nPr) and combinations (nCr) exactly, even for large numbers, plus the counts with repetition.

Z-Score Calculator

Find the z-score of a value from the mean and standard deviation, plus its percentile under the normal curve, with steps and a shaded bell curve.

Linear Regression Calculator

Find the least-squares line of best fit y = mx + c, the correlation coefficient r and r², with a scatter plot showing the residuals.

Box Plot & Quartile Calculator

Find the five-number summary, quartiles, interquartile range and outliers of a data set, and draw an animated box-and-whisker plot.

Poisson Distribution Calculator

Find Poisson probabilities for exactly, at most or at least k events given an average rate λ, with the formula and a bar chart.

Variance Calculator

Calculate the exact variance of a data set for a sample or a population, with the squared deviations shown and the shortcut formula check.

Percentile Rank Calculator

Find the percentile rank of a value in a data set: the percentage of values below it, counting ties fairly, with a highlighted chart.

Probability Calculator

Find P(A and B), P(A or B), P(not A) and P(A given B) for independent, mutually exclusive or related events, exactly with fractions.

Expected Value Calculator

Find the expected value, variance and standard deviation of a discrete probability distribution, exactly, with a bar chart.

Confidence Interval Calculator

Find a confidence interval for a mean from the sample mean, standard deviation and sample size at 80–99% confidence, with the margin of error.

Dice Probability Calculator

Find the exact probability of rolling a total with any number of dice and sides (d6, d20 …): exactly, at most or at least, with a chart.