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 probability for medical tests, diagnostics & conditional probability.
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 Coefficient Calculator
Free correlation coefficient calculator. Calculate Pearson's r, R-squared, and significance for any dataset with step-by-step interpretation.
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
Free probability calculator for unions, intersections, complements & conditional probability. Calculate P(A or B), P(A and B), P(not A), P(A|B).
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
Free online standard deviation calculator. Calculate SD, variance, mean & more for any dataset. Supports both sample and population calculations.
T-Test Calculator
Free t-test calculator for one-sample, two-sample & paired t-tests. Calculate t-value, p-value, degrees of freedom with step-by-step results.
Sample Size Calculator
Free sample size calculator for surveys, research & experiments. Calculate required n for means, proportions & group comparisons with confidence.
Z-Score Calculator
Free z-score calculator to standardize values and find percentiles. Calculate z-values from raw scores or convert z-scores back to original values.
Learn the Theory
Understand the statistical concepts behind these calculators with our comprehensive lessons.
Browse LessonsStatistical Tables
Access z-tables, t-tables, chi-square tables, and F-tables for manual lookups and reference.
View TablesFree Online Statistics Calculators
Our collection of free statistics calculators helps students, researchers, and professionals perform complex statistical analyses quickly and accurately. Each calculator provides step-by-step solutions so you can understand the methodology, not just the results.
Most Popular Calculators
- Standard Deviation Calculator - Calculate standard deviation (SD), variance, mean, and other descriptive statistics for any dataset. Supports both sample and population calculations.
- Sample Size Calculator - Determine the minimum sample size needed for your survey or research study based on confidence level, margin of error, and expected effect size.
- Correlation Coefficient Calculator - Calculate Pearson's correlation coefficient (r), R-squared, and test statistical significance between two variables.
- Probability Calculator - Compute complements, unions, intersections, and conditional probabilities using fundamental probability rules.
- Bayes Theorem Calculator - Calculate posterior probabilities for medical tests, diagnostics, and decision-making under uncertainty.
- T-Test Calculator - Perform one-sample, two-sample, and paired t-tests with automatic p-value calculation.
- Z-Score Calculator - Convert raw scores to z-scores and find probabilities using the standard normal distribution.
Why Use Our Calculators?
- 100% Free - No signup, no subscription, no hidden fees
- Step-by-Step Solutions - See exactly how each calculation is performed
- Accurate Results - Uses validated statistical formulas and methods
- Mobile-Friendly - Works on any device—phone, tablet, or computer
- No Software Required - Run calculations directly in your browser
Choosing the Right Calculator
| If you need to... | Use this calculator |
|---|---|
| Summarize data (mean, SD, variance) | Standard Deviation Calculator |
| Plan a study or survey | Sample Size Calculator |
| Measure relationship between variables | Correlation Calculator |
| Compare two group means | T-Test Calculator |
| Update probabilities with new evidence | Bayes Theorem Calculator |
| Build confidence intervals | Confidence Interval Calculator |