Mean Calculator
Compute the arithmetic mean with full step-by-step breakdown. Also outputs range, variance, and standard deviation.
Central Limit Theorem
Intermediate
T-Test
Intermediate
Normal Distribution
Intermediate
Z Score
Beginner
Confidence Interval
Intermediate
Standard Deviation
Intermediate
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Median Calculator
Find the median instantly. Supports comma, space, or newline inputs with step-by-step solutions for odd and even counts.
Mean Median Mode Calculator
Calculate mean, median, and mode simultaneously with step-by-step solutions and frequency insights.
Descriptive Statistics Calculator
Mean, median, mode, variance, SD, quartiles, IQR, skewness, and kurtosis. The most complete single-dataset summary tool.
Standard Deviation Calculator
Calculate population (σ) and sample (s) standard deviation with a full formula breakdown showing every step.
Z Score Calculator
Enter a score, mean, and SD to get the z score instantly. Includes bell curve visualization and probability interpretation.
Five Number Summary Calculator
Find min, Q1, median, Q3, and max to summarize your dataset for box plots and exploratory data analysis.
Chebyshev's Theorem Calculator
Calculate Chebyshev's interval and the minimum proportion within k standard deviations for any distribution.
Margin of Error Calculator
Calculate margin of error for survey results using sample size, confidence level, and population proportion.
Class Width Calculator
Calculate class width for grouped frequency distributions using the data range and number of classes, with a clear step-by-step result.
Dot Plot Calculator
Create a dot plot from a dataset to visualize the distribution, frequency, center, spread, clusters, gaps, and potential outliers.
Box Plot Calculator
Generate a box plot and calculate the five-number summary, quartiles, interquartile range, whiskers, and potential outliers from your data.
IQR Calculator
Find the interquartile range (Q3 minus Q1) to describe the spread of the middle half of a dataset.
Percentile Calculator
Explore percentile ranks and positions in a dataset to understand relative standing.
Weighted Average Calculator
Calculate a mean that assigns different weights to different values.
Probability Calculator
Calculate basic, conditional, and joint probabilities for independent and dependent events with step-by-step solutions.
Conditional Probability Calculator
Calculate P(A|B) using the conditional probability formula. Shows how one event's occurrence changes another's probability.
Bayes' Theorem Calculator
Calculate posterior probability from prior, likelihood, and evidence. Shows step by step how new data updates predictions.
Expected Value Calculator
Calculate E(X) of a discrete probability distribution using outcomes and their corresponding probabilities.
Combination Calculator
Calculate C(n, r) — selecting r items from n without regard to order. Shows all factorial steps clearly.
Birthday Paradox Calculator
Calculate the probability two or more people in a group share a birthday. Explore why small groups have high match odds.
Boy or Girl Paradox Calculator
Calculate conditional probabilities for the Boy or Girl Paradox and see how context changes the likelihood.
Bertrand's Box Paradox Calculator
Explore the famous three-box paradox. Calculate conditional probabilities step by step with full explanation.
Coin Flip Probability Calculator
Calculate the probability of getting a specific number of heads or tails. Includes a live coin flipper simulator.
Dice Average Calculator
Calculate the expected average roll for any number of dice with any number of sides. Ideal for exploring discrete probability distributions.
Coin Toss Streak Calculator
Calculate the probability of getting a streak of consecutive heads or tails in a given number of coin tosses. Great for exploring the law of large numbers.
Coin Flipper
Flip a virtual coin to generate heads-or-tails outcomes and explore randomness.
Dice Probability Calculator
Explore the probability of outcomes from dice rolls, including different totals and events.
Password Combination Calculator
Explore the number of possible password combinations for different character choices and lengths.
Permutation Calculator
Count ordered arrangements and compare permutations with combinations.
T-Test Calculator
One-sample, paired, two-sample, and Welch's t-tests. Get t-value, p-value, CI, effect size, and full solutions.
Z-Test Calculator
One-sample and two-sample z-tests for when the population standard deviation is known.
Chi-Square Calculator
Goodness-of-fit and independence tests. Get expected frequencies, p-values, and degrees of freedom step by step.
ANOVA Calculator
One-way ANOVA for comparing multiple group means. F-statistic, p-value, and significance — step by step.
Confidence Interval Calculator
CI for means and proportions using z and t intervals. Margin of error, critical values, and visual results.
Effect Size Calculator
Cohen's d and related measures. Assess practical significance and interpret results beyond just the p-value.
A/B Test Calculator
Compare conversion rates, calculate p-values and confidence intervals to determine statistical significance.
Bonferroni Correction Calculator
Adjust your significance threshold for multiple comparisons to prevent false positives.
Critical Value Calculator
Find critical values for z, t, chi-square, and F distributions by significance level and degrees of freedom.
P-Value Calculator
Work with p-values when assessing evidence against a statistical null hypothesis.
Power Analysis Calculator
Explore statistical power and its relationship to sample size, effect size, and significance level.
Normal Distribution Calculator
Z-scores, probabilities, PDF, and CDF. Left-tail, right-tail, two-tailed, and inverse modes with bell curve visualization.
Binomial Distribution Calculator
Calculate PMF and CDF for a fixed number of independent trials with a constant success probability.
Poisson Distribution Calculator
Probability of a given number of events in a fixed interval when events occur at a known constant rate.
Normal Approximation Calculator
Estimate binomial probabilities using the normal approximation. Includes continuity correction and z-score steps.
Central Limit Theorem Calculator
Sampling distribution, standard error, and probability using the CLT. Essential for large-sample statistical inference.
Sample Size Calculator
Required sample size given confidence level, margin of error, and population size. Essential for study planning.
Continuity Correction Calculator
Apply the continuity correction when approximating a discrete distribution with a continuous normal distribution, with corrected boundaries and probability calculations.
Beta Distribution Calculator
Calculate beta distribution probabilities, probability density, cumulative probabilities, and percentiles using customizable alpha and beta parameters.
Empirical Rule Calculator
Use the 68-95-99.7 rule to estimate the percentage of data within one, two, and three standard deviations of the mean for a normal distribution.
Simple Linear Regression Calculator
Regression equation, slope, intercept, and R² with step-by-step explanation and scatter plot output.
Pearson Correlation Calculator
Calculate Pearson's r with covariance, R², p-values, and scatter plot. Full step-by-step breakdown.
Applied & clinical statistics
11 calculatorsOdds Ratio Calculator
Odds ratio, CI, and related statistics from a 2×2 contingency table for case-control studies.
Relative Risk Calculator
Risk ratio from exposed and unexposed groups. Compares event probabilities in cohort and clinical research.
Post-Test Probability Calculator
Probability of a condition after a diagnostic test using pre-test probability, sensitivity, and specificity.
Accuracy Calculator
Classification accuracy from correct vs total predictions. Quick model performance evaluation.
Confusion Matrix Calculator
Accuracy, precision, recall, F1 score, and specificity from a confusion matrix in one step.
McNemar Test Calculator
McNemar's test for paired nominal data. Test for significant change between paired observations from a 2×2 table.
Benford's Law Calculator
Test whether your dataset's leading digit distribution conforms to Benford's Law. Used in fraud detection, forensic accounting, and data quality analysis.
Wilson Score Calculator
Confidence intervals for a proportion using successes, total trials, and a chosen confidence level.
False Positive Paradox Calculator
Explore how test accuracy and prevalence influence the chance that a positive result is correct.
Risk Calculator
Explore risk estimates for an event using the inputs and definitions provided by the calculator.
Sensitivity and Specificity Calculator
Evaluate diagnostic test performance using sensitivity, specificity, and related measures.
GPA & Final Grade Calculator
Explore course-grade calculations, GPA, and the grade needed to reach an academic target.
Percentage Calculator
Calculate percentages and solve common part–whole percentage problems.
Percentage Change Calculator
Calculate relative increases and decreases between an original and a new value.
Dice Roller
Roll virtual dice for games, probability experiments, or classroom practice.
Random Number Generator
Generate random numbers for sampling, experiments, or everyday number selection.
Random Password Generator
Generate randomized password strings with options provided by the tool.
Frequently asked questions
For a full dataset summary, use the Descriptive Statistics Calculator — it covers mean, median, mode, SD, variance, quartiles, and kurtosis in one tool. For comparing two group means, use the T-Test Calculator. All 69 calculators on this page are free, browser-based, and require no account or download.
Use Descriptive Statistics for a single dataset. Use T-Test for two group means. Use ANOVA for three or more groups. Use Chi-Square for categorical data. Use Pearson Correlation for linear relationships. Not sure? Try the statistical test selector.
Enter comma-separated values into the Standard Deviation Calculator. It calculates both population (σ) and sample (s) SD with a full step-by-step breakdown. For a complete summary including quartiles and IQR, use the Descriptive Statistics Calculator instead.
A z-test is often appropriate for normal-model mean inference when population SD is known. A t-test accounts for estimating population SD from a sample. The best test also depends on your study design and assumptions. Read the t-test vs z-test guide.
Yes. All 69 calculators are fully responsive and work on phones, tablets, and desktops with no app download or account required. Results appear instantly as you enter data.