132+ Free Calculators

Statistics Calculators

132+ free calculators for descriptive statistics, hypothesis tests, confidence intervals, and more. No signup required.

Descriptive Statistics

23 tools

Mean Calculator

Calculate the arithmetic mean (average) of a dataset.

Descriptive

Median Calculator

Find the middle value of a sorted dataset.

Descriptive

Mode Calculator

Find the most frequently occurring value(s).

Descriptive

Weighted Average Calculator

Calculate weighted mean with custom weights.

Descriptive

Standard Deviation Calculator

Measure the spread of data around the mean.

Descriptive

Variance Calculator

Calculate the squared deviation from the mean.

Descriptive

Standard Error Calculator

Calculate the standard error of a statistic.

Descriptive

Standard Error of the Mean Calculator

Calculate SEM from sample data.

Descriptive

Coefficient of Variation Calculator

Calculate relative variability as a percentage.

Descriptive

Range Calculator

Find the difference between max and min values.

Descriptive

Interquartile Range Calculator

Calculate IQR, the spread of the middle 50%.

Descriptive

Quartile Calculator

Calculate Q1, Q2 (median), and Q3.

Descriptive

Percentile Calculator

Find the value at any percentile or rank.

Descriptive

Five-Number Summary Calculator

Get min, Q1, median, Q3, and max.

Descriptive

Z-Score Calculator

Convert values to standard scores.

Descriptive

Outlier Calculator

Detect outliers using the Tukey fence method.

Descriptive

Skewness Calculator

Measure asymmetry of the distribution.

Descriptive

Kurtosis Calculator

Measure tail heaviness of the distribution.

Descriptive

Geometric Mean Calculator

Calculate mean for multiplicative data.

Descriptive

Harmonic Mean Calculator

Calculate mean for rates and ratios.

Descriptive

Box-Cox Transformation Calculator

Transform data to normality.

Descriptive

Moving Average Calculator

Smooth time series data.

Descriptive

Process Capability Calculator

Measure process performance.

Descriptive

Confidence Intervals & Estimation

15 tools

Confidence Interval Calculator for Mean

Calculate CI for a population mean.

Confidence

Confidence Interval Calculator for Proportion

Calculate CI for a population proportion.

Confidence

Confidence Interval Calculator for Difference in Means

Calculate CI for the difference between two means.

Confidence

Confidence Interval Calculator for Difference in Proportions

Calculate CI for the difference between two proportions.

Confidence

Margin of Error Calculator

Calculate margin of error for surveys.

Confidence

Critical Value Calculator (z*)

Find z* for any confidence level.

Confidence

Critical Value Calculator (t*)

Find t* for any confidence level and df.

Confidence

Pooled Standard Deviation Calculator

Calculate pooled SD for two groups.

Confidence

Standard Error of Proportion Calculator

Calculate SE for a sample proportion.

Confidence

Cohen's d Calculator

Calculate standardized effect size.

Confidence

Odds Ratio Calculator

Calculate OR with confidence interval.

Confidence

Relative Risk Calculator

Calculate RR with confidence interval.

Confidence

Number Needed to Treat (NNT) Calculator

Calculate clinical significance.

Confidence

Bayesian Proportion Calculator

Estimate proportions with prior beliefs.

Confidence

Bootstrap Confidence Interval Calculator

Estimate CIs via resampling.

Confidence

Distributions & P-Values

24 tools

P-Value from Z-Score Calculator

Convert z-score to p-value.

Distributions

Z-Table Calculator

Find area under the normal curve.

Distributions

Normal Probability Calculator

Find probability between two values.

Distributions

Binomial Distribution Calculator (PMF)

Calculate P(X = k) for binomial trials.

Distributions

Binomial Distribution Calculator (CDF)

Calculate P(X ≤ k) for binomial trials.

Distributions

Poisson Probability Calculator

Calculate probability for Poisson events.

Distributions

Poisson Rate Calculator

Estimate rate from observed events.

Distributions

T-Distribution Calculator

Calculate p-value from t-statistic.

Distributions

Chi-Square Distribution Calculator

Calculate p-value from chi-square statistic.

Distributions

F-Distribution Calculator

Calculate p-value from F-statistic.

Distributions

Inverse Normal Calculator

Find z-score from percentile.

Distributions

Inverse T Calculator

Find t-value from percentile.

Distributions

Inverse Chi-Square Calculator

Find chi-square value from percentile.

Distributions

Inverse F Calculator

Find F-value from percentile.

Distributions

Degrees of Freedom Calculator

Calculate df for common tests.

Distributions

Random Number Generator

Generate random numbers from distributions.

Distributions

Negative Binomial Calculator

Model overdispersed count data.

Distributions

Bayes' Theorem Calculator

Calculate conditional probabilities using Bayes' theorem.

Distributions

Combinations & Permutations Calculator

Calculate nCr and nPr.

Distributions

Expected Value Calculator

Calculate weighted average outcome.

Distributions

Exponential Distribution Calculator

Model time between events.

Distributions

Geometric Distribution Calculator

Trials until first success.

Distributions

Hypergeometric Distribution Calculator

Sampling without replacement.

Distributions

Beta Distribution Calculator

Model probabilities and proportions.

Distributions

Sample Size & Power

10 tools

Sample Size Calculator for Two Means

Calculate n for comparing two means.

Sample Size

Sample Size Calculator for Two Proportions

Calculate n for comparing two proportions.

Sample Size

Statistical Power Calculator

Calculate power given sample size.

Sample Size

Minimum Detectable Effect Calculator

Find the smallest effect you can detect.

Sample Size

A/B Test Sample Size Calculator

Plan your A/B test sample size.

Sample Size

A/B Test Significance Calculator

Analyze your A/B test results.

Sample Size

Conversion Rate CI Calculator

Calculate CI for conversion rates.

Sample Size

Bayesian A/B Test Calculator

Bayesian approach to A/B testing.

Sample Size

Survey Sample Size Calculator

Calculate n for survey margin of error.

Sample Size

Finite Population Correction Calculator

Adjust for small populations.

Sample Size

Hypothesis Tests

33 tools

One-Sample T-Test Calculator

Test if mean differs from a value.

Tests

Two-Sample T-Test Calculator

Compare means of two independent groups.

Tests

Paired T-Test Calculator

Compare means of paired observations.

Tests

Welch's T-Test Calculator

T-test for unequal variances.

Tests

One-Way ANOVA Calculator

Compare means across 3+ groups.

Tests

Two-Way ANOVA Calculator

Test effects of two factors.

Tests

Repeated Measures ANOVA Calculator

ANOVA for within-subjects designs.

Tests

Tukey HSD Calculator

Post-hoc pairwise comparisons.

Tests

Chi-Square Test Calculator

Test independence in contingency tables.

Tests

Chi-Square Goodness of Fit Calculator

Test if data fits expected distribution.

Tests

Fisher's Exact Test Calculator

Exact test for 2×2 tables.

Tests

One Proportion Z-Test Calculator

Test if proportion differs from a value.

Tests

Two Proportion Z-Test Calculator

Compare two proportions.

Tests

Binomial Test Calculator

Exact test for proportions.

Tests

Mann-Whitney U Test Calculator

Non-parametric test for two groups.

Tests

Wilcoxon Signed-Rank Test Calculator

Non-parametric paired test.

Tests

Kruskal-Wallis Test Calculator

Non-parametric test for 3+ groups.

Tests

Shapiro-Wilk Test Calculator

Test data for normality.

Tests

Levene's Test Calculator

Test equality of variances.

Tests

Sign Test Calculator

Simple non-parametric paired test.

Tests

McNemar's Test Calculator

Test for paired categorical data.

Tests

Friedman Test Calculator

Non-parametric repeated measures test.

Tests

Bonferroni Correction Calculator

Adjust p-values for multiple comparisons.

Tests

ANCOVA Calculator

ANOVA with a covariate.

Tests

Kaplan-Meier Survival Calculator

Analyze time-to-event data.

Tests

Eta-Squared & Omega-Squared Calculator

Calculate ANOVA effect sizes.

Tests

Hedges' g & Glass's Delta Calculator

Alternative standardized effect sizes.

Tests

Hazard Ratio Calculator

Compare survival between groups.

Tests

Log-Rank Test Calculator

Compare survival curves between groups.

Tests

Confusion Matrix Calculator

Calculate classification metrics.

Tests

Propensity Score Calculator

Estimate treatment assignment probability.

Tests

Kolmogorov-Smirnov Test Calculator

Test distribution fit or compare samples.

Tests

Control Chart Calculator

Monitor process stability.

Tests

Correlation & Regression

18 tools

Pearson Correlation Calculator

Measure linear relationship strength.

Regression

Spearman Correlation Calculator

Rank-based correlation measure.

Regression

Correlation P-Value Calculator

Test significance of correlation.

Regression

Linear Regression Calculator

Fit a line to predict Y from X.

Regression

Multiple Linear Regression Calculator

Regression with multiple predictors.

Regression

Logistic Regression Calculator

Model binary outcomes.

Regression

R-Squared Calculator

Calculate coefficient of determination.

Regression

ROC Curve Calculator

Evaluate classifier performance.

Regression

Cramér's V Calculator

Effect size for chi-square tests.

Regression

Cronbach's Alpha Calculator

Measure internal consistency.

Regression

Intraclass Correlation (ICC) Calculator

Measure inter-rater reliability.

Regression

Kendall's Tau Calculator

Rank correlation with ties.

Regression

Bland-Altman Analysis Calculator

Compare two measurement methods.

Regression

Point-Biserial Correlation Calculator

Correlate binary and continuous variables.

Regression

Phi Coefficient Calculator

Measure association in 2×2 tables.

Regression

Partial Correlation Calculator

Correlate variables controlling for others.

Regression

AIC & BIC Calculator

Compare model fit with information criteria.

Regression

Cohen's Kappa Calculator

Measure inter-rater agreement.

Regression

Statistical Tables

9 tools

Z-Table (Standard Normal)

Standard normal distribution table.

Tables

t-Table (Student's t)

Critical values for t-distribution.

Tables

Chi-Square Table

Critical values for chi-square distribution.

Tables

F-Table

Critical values for F-distribution.

Tables

Critical r Table (Correlation)

Critical values for Pearson correlation.

Tables

Studentized Range q Table

Critical values for Tukey HSD test.

Tables

Durbin-Watson Table

Critical values for autocorrelation test.

Tables

Mann-Whitney U Table

Critical values for Mann-Whitney test.

Tables

Wilcoxon Signed-Rank Table

Critical values for Wilcoxon test.

Tables