Free Statistics Calculators
Professional-grade statistical calculators at your fingertips. Get instant results with detailed step-by-step explanations—all completely free.
All Calculators
Bayes' Theorem Calculator
Free Bayes' theorem calculator with step-by-step solutions. Calculate posterior probabilities for medical tests and diagnostics.
Bartlett's Test Calculator
Free online Bartlett's test calculator for testing equality of variances. Test homoscedasticity across multiple groups with step-by-step results.
Combinations and Permutations Calculator
Free calculator for combinations and permutations with and without repetition. Calculate nCr, nPr, and get step-by-step solutions for counting problems.
Correlation Calculator
Calculate Pearson correlation coefficient between two variables. Get r, r², significance test, and interpretation instantly.
Confidence Interval Calculator
Calculate confidence intervals for population means with this free calculator. Get step-by-step explanations and interpretations.
Event Counter & Frequency Tracker
Free online event counter for behavioral observations, research, and data collection. Track multiple events with timing, statistics, and export features.
Histogram Generator
Create histograms and frequency distributions from your data. Visualize data distribution with automatic binning and detailed statistics.
Descriptive Statistics Calculator
Free online descriptive statistics calculator. Compute mean, median, mode, standard deviation, variance, quartiles, skewness, and more from your data.
Mean Calculator
Calculate the arithmetic mean (average) of any dataset instantly. Free online mean calculator with step-by-step explanations.
Factorial Calculator
Free factorial calculator supporting n!, double factorial (n!!), subfactorial (!n), and gamma function. Calculate large factorials with step-by-step solutions.
Probability Calculator
Calculate probabilities including complements, unions, intersections, and conditional probabilities. Learn probability rules with step-by-step solutions.
Random Number Generator
Free online random number generator for integers, decimals, normal distributions, and random sampling. Perfect for statistics, simulations, and research.
Standard Deviation Calculator
Calculate standard deviation and variance for any dataset. Free online calculator supporting both population and sample calculations with detailed steps.
T-Test Calculator
Perform one-sample and two-sample t-tests online. Calculate t-statistics, p-values, and determine statistical significance instantly.
Sample Size Calculator
Free sample size calculator for surveys and research. Calculate required sample size for proportions, means, and group comparisons.
Z-Score Calculator
Calculate z-scores to standardize values or find the original value from a z-score. Includes percentile calculations and visual representation.
Learn the Theory
Understand the statistical concepts behind these calculators with our comprehensive lessons.
Browse LessonsStatistics Glossary
Look up definitions for statistical terms and concepts used in these calculators.
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