Statistics Calculators

Free statistics calculators for mean, median, mode, standard deviation, probability and regression — accurate results instantly.

Descriptive Statistics

Mean, Median & Mode CalculatorFind the mean, median and mode of a dataset.Standard Deviation CalculatorMeasure how spread out a dataset is from its mean.Variance CalculatorFind the sample and population variance of a dataset.Range CalculatorFind the range (max minus min) of a dataset.Z-Score CalculatorFind how many standard deviations a value is from the mean.Coefficient of Variation CalculatorMeasure relative variability as a percentage of the mean.Interquartile Range (IQR) CalculatorFind the IQR and quartiles of a dataset.Correlation Coefficient Calculator (Pearson's r)Measure the linear relationship strength between two datasets.Covariance CalculatorMeasure how two datasets vary together.Five-Number Summary CalculatorFind the minimum, quartiles, median and maximum of a dataset.Outlier Calculator (1.5×IQR Rule)Detect outliers in a dataset using the 1.5×IQR rule.Sum of Squares CalculatorFind the sum of squared deviations from the mean of a dataset.Decile CalculatorSplit a dataset into ten equal parts (deciles).Skewness CalculatorMeasure the asymmetry of a dataset's distribution.Median CalculatorFind the median (middle value) of a dataset.Mode CalculatorFind the most frequently occurring value in a dataset.Ordering Numbers CalculatorSort a list of numbers in ascending or descending order.Spearman's Rank Correlation CalculatorMeasure the monotonic relationship strength between two ranked datasets.

Distributions

Confidence Interval CalculatorFind the confidence interval for a sample mean.Percentile CalculatorFind the percentile rank of a value within a dataset.Normal Distribution CalculatorFind the z-score, density and cumulative probability for a normal distribution.Binomial Distribution CalculatorFind the probability of k successes in n independent trials.Poisson Distribution CalculatorFind the probability of a number of events occurring in a fixed interval.Empirical Rule Calculator (68-95-99.7)Find the 68-95-99.7 ranges of a normal distribution from mean and stddev.Uniform Distribution CalculatorFind the probability of a value in a continuous uniform range.Exponential Distribution CalculatorFind the probability of waiting time using the exponential distribution.Geometric Distribution CalculatorFind the probability that the first success happens on trial k.Hypergeometric Distribution CalculatorFind the probability of successes when sampling without replacement.Class Width CalculatorFind the class width needed to build a histogram or frequency table.Inverse Normal Distribution CalculatorFind the value x for a given cumulative probability.Frequency Distribution CalculatorCount how often each value appears in a dataset.Stem and Leaf Plot Data CalculatorOrganize a dataset into a stem-and-leaf plot.Dot Plot Data CalculatorBuild a dot plot showing the frequency of each value.Pie Chart Percentage CalculatorConvert a list of category values into pie chart percentages and angles.Histogram CalculatorGroup a dataset into equal-width bins and count values in each.

Inference & Regression

Linear Regression CalculatorFind the least-squares regression line for two datasets.Margin of Error CalculatorFind the margin of error for a survey or poll result.Sample Size CalculatorFind the survey sample size needed for a target margin of error.Standard Error of the Mean CalculatorFind how precisely a sample mean estimates the population mean.P-Value Calculator (from Z-Score)Find the p-value for a z-score in a hypothesis test.Confusion Matrix CalculatorFind accuracy, precision, recall and F1 score from a confusion matrix.Two-Sample T-Test CalculatorCompare two sample means with an independent two-sample t-test.One-Sample Z-Test CalculatorTest a sample mean against a hypothesized value using a z-test.Degrees of Freedom CalculatorFind degrees of freedom for common one- and two-sample tests.Critical Value Calculator (t or z)Find the t or z critical value for a given confidence level.F-Statistic Calculator (One-Way ANOVA)Find the F-ratio for a simplified one-way ANOVA with three groups.Residual CalculatorFind residuals and error metrics from actual and predicted values.Exponential Regression CalculatorFit an exponential curve y = ae^(bx) to a dataset.A/B Test Significance CalculatorTest whether the difference in conversion rates between two groups is statistically significant.Chi-Square Goodness-of-Fit CalculatorTest whether observed frequencies match expected frequencies.One-Sample T-Test CalculatorTest whether a sample mean differs from a hypothesized value.Polynomial Regression Calculator (Quadratic)Fit a quadratic curve y = ax² + bx + c to a dataset.Statistical Power Calculator (Two-Sample Test)Estimate the statistical power of a two-sample test to detect a given effect.Mann-Whitney U Test CalculatorCompare two independent samples with the nonparametric Mann-Whitney U test.

Probability Theory

Probability CalculatorFind the probability of a single event occurring.Combination Calculator (nCr)Find how many ways to choose r items from n when order does not matter.Permutation Calculator (nPr)Find how many ways to arrange r items from n when order matters.Expected Value CalculatorFind the long-run average outcome of a set of weighted possibilities.Bayes' Theorem CalculatorUpdate a probability estimate after new evidence using Bayes theorem.Dice Probability CalculatorFind the probability of rolling a specific sum with multiple dice.Coin Flip Probability CalculatorFind the probability of getting a certain number of heads in n flips.Birthday Paradox CalculatorFind the probability that two people in a group share a birthday.Odds CalculatorConvert a probability into odds in favor and against.Conditional Probability CalculatorFind the probability of event A given that event B has occurred.Sensitivity and Specificity CalculatorFind a medical test’s true positive and true negative rates.Relative Risk CalculatorCompare the risk of an outcome between two groups.Monty Hall Problem CalculatorFind the odds of winning by switching versus staying.Random Number GeneratorGenerate a random whole number within a chosen range.Password Combination CalculatorFind the total number of possible passwords for a character set.Shannon Entropy CalculatorMeasure the uncertainty or information content of a probability set.Venn Diagram Overlap CalculatorFind union, only-A and only-B counts from two overlapping sets.Dice Roller CalculatorSimulate rolling multiple dice and see the total.Decimal Odds CalculatorConvert a probability into decimal odds and payout.Fractional Odds CalculatorConvert a probability into fractional (UK-style) betting odds.