Statistics Tools
Choose a calculator for formulas, live results, charts, examples, FAQ, glossary and references.
- Mean Median Mode Calculator
Mean median mode calculator for central tendency, range, quartiles, variance and standard deviation with live chart, formulas and steps.
- Standard Deviation Calculator
Standard deviation calculator for sample and population SD with variance, mean, deviations, formulas, chart and step-by-step working.
- Variance Calculator
Variance calculator for sample s squared and population sigma squared with coefficient of variation, formula, chart and steps.
- Z Score Calculator
Z score calculator for z=(x-mu)/sigma, percentile from normal CDF, reverse x from z, formula and bell curve.
- P Value Calculator
P value calculator from Z, t, chi-square and F statistics with one-tailed and two-tailed results, formulas and interpretation.
- T Test Calculator
T test calculator for one-sample, Welch two-sample and paired tests with t statistic, df, p-value, effect size and steps.
- Confidence Interval Calculator
Confidence interval calculator for means and proportions using z or t critical values, margin of error, formula and steps.
- Probability Calculator
Probability calculator for union, intersection, conditional probability, complement and normal CDF with formulas and Venn chart.
- Sample Size Calculator
Sample size calculator for means and proportions with confidence level, margin of error and finite population correction.
- Combination Permutation Calculator
Combination permutation calculator for nCr, nPr, repetition formulas and factorials using BigInt for large exact integers.
- Chi Square Calculator
Chi square calculator for goodness-of-fit and contingency table independence tests with p-value, df and steps.
- Correlation Coefficient Calculator
Correlation coefficient calculator for Pearson r, Spearman rho, t test, p-value, strength interpretation and scatter plot.
- Linear Regression Calculator
Linear regression calculator for simple OLS best-fit line, slope, intercept, R squared, prediction and scatter plot.
- Margin Of Error Calculator
Margin of error calculator for means and proportions with confidence level, z critical value, formula and interpretation.
- Five Number Summary Calculator
Five number summary calculator for min, Q1, median, Q3, max, IQR, fences, outliers and live box plot.