Statistics Calculators
34 free statistics calculators in Math. The first 5 have a full write-up: the method, a worked example and questions specific to that calculator.
- Confidence Interval CalculatorBuild confidence intervals for a mean or proportion at any confidence level.
- P-value CalculatorConvert a test statistic into a p-value for z, t and chi-square tests.
- Sample Size CalculatorDetermine the sample size needed for a target margin of error and confidence.
- Standard Deviation CalculatorCompute population and sample standard deviation, variance and standard error.
- Statistics CalculatorFull descriptive statistics for a dataset: centre, spread, quartiles, skew and outliers.
- ANOVA CalculatorPerform one-way ANOVA: compute SSB, SSW, F statistic and p-value for group means comparison.
- Binomial Distribution CalculatorCalculate PMF, CDF, mean and variance for the binomial distribution B(n,p).
- Binomial ProbabilityFree Binomial Probability calculator with clear step-by-step results.
- Chi-Square CalculatorRun a chi-square goodness-of-fit test comparing observed vs expected frequencies.
- Correlation CalculatorCompute Pearson's correlation coefficient r between two paired datasets.
- Covariance CalculatorCalculate sample or population covariance between two paired datasets.
- Expected Value CalculatorCompute the expected value E[X] from a discrete probability distribution table.
- F-Test CalculatorCompare two sample variances with an F-test, returning the F statistic and p-value.
- Five Number Summary CalculatorReport the minimum, Q1, median, Q3 and maximum of a dataset for box-plot construction.
- Geometric Distribution CalculatorCalculate PMF, CDF, mean and variance for the geometric distribution (trials until first success).
- IQR CalculatorCalculate the interquartile range (Q3 − Q1) as a robust measure of spread.
- Linear Regression CalculatorFit a least-squares line y = mx + b to paired data and report slope, intercept and R².
- Margin of Error CalculatorCalculate the margin of error for a survey or poll given sample size and confidence level.
- Mean, Median, Mode, Range CalculatorFind all four measures of centre and spread for any list of numbers.
- Multiple Regression CalculatorFit a multiple linear regression y = b₀ + b₁x₁ + b₂x₂ for two predictors using normal equations.
- Normal Distribution CalculatorCompute PDF, CDF, and inverse CDF for the normal (Gaussian) distribution with given μ and σ.
- Outlier Detection CalculatorIdentify outliers in a dataset using Tukey's 1.5×IQR fence method.
- Percentile CalculatorFind the value at any percentile rank in a dataset using linear interpolation.
- Poisson Distribution CalculatorCalculate PMF, CDF, mean and variance for the Poisson distribution with rate λ.
- Poisson ProbabilityFree Poisson Probability calculator with clear step-by-step results.
- Probability Distribution CalculatorCalculate PMF/PDF, CDF, mean and variance for common discrete and continuous distributions.
- Quartiles CalculatorCompute Q1, Q2, Q3 from a dataset using the percentile interpolation method.
- Range Calculator (Statistics)Find the statistical range (max − min) of a dataset with extremes identified.
- Regression PredictionFree Regression Prediction calculator with clear step-by-step results.
- T Score CalculatorConvert a raw score to a T score (mean 50, SD 10) given the group mean and standard deviation.
- T-Test CalculatorPerform a one-sample or two-sample t-test with t statistic, degrees of freedom and p-value.
- Uniform Distribution CalculatorCalculate PDF, CDF, mean and variance for the continuous uniform distribution on [a, b].
- Variance CalculatorCalculate population or sample variance from a dataset with step-by-step squared deviations.
- Z-score CalculatorConvert between z-scores, raw values and normal distribution probabilities.