Statistics & Probability
Summarise data sets, compute probabilities and fit regression lines. Sample and population formulas are kept separate, and counts are computed exactly with big integers.
Statistics CalculatorMean, median, mode, range, variance, standard deviation, quartiles, percentiles, IQR and outliers for a data set — sample or population.Data VisualizerTurn a data set into a histogram, box plot, bar chart, line chart or scatter plot, with a fitted normal curve and shape analysis.Frequency Table GeneratorBuild a frequency table with relative and cumulative frequencies, or group data into class intervals; export to CSV.Probability CalculatorBasic, complement, conditional, independent and dependent event probabilities with the rule used shown for each result.Bayes' Theorem CalculatorUpdate a probability with Bayes’ theorem from a prior, a true-positive rate and a false-positive rate, with the full working.Permutations & Combinations CalculatorExact nPr, nCr and factorials for large numbers, with and without repetition, using big-integer arithmetic.Normal Distribution CalculatorNormal probabilities below, above or between values, the density, and inverse lookups, with the shaded bell curve.Binomial Distribution CalculatorBinomial probabilities P(X = k), P(X ≤ k) and P(X ≥ k) with mean, variance and the full probability chart.Poisson Distribution CalculatorPoisson probabilities for a given rate λ: exactly k events, at most k and at least k, with the probability chart.Uniform Distribution CalculatorContinuous uniform distribution on [a, b]: density, cumulative probability, interval probability, mean and variance.Regression CalculatorLeast-squares linear regression: slope, intercept, r, R², standard error and predictions, with the scatter plot and fitted line.Correlation CalculatorPearson and Spearman correlation coefficients for paired data, with r² and a plain-language strength description.Z-Score CalculatorStandard score of a value, the percentile it corresponds to under a normal distribution, and the tail probabilities.