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    Free Statistics Calculators 2026 – Mean, SD, Z-Score & More

    Professional statistics calculators for students, researchers, and data analysts. Compute descriptive statistics, run hypothesis tests, calculate z-scores, p-values, and confidence intervals — all free, instant, and accurate.

    ✓ 24 All Online Calculators✓ No login required✓ Mobile Ready

    Most searched in this category

    Standard DeviationZ-Score CalculatorMean Median Mode

    Most Popular

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    T-Test

    Perform an independent samples t-test to compare means of two groups.

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    Variance

    Calculate population or sample variance and standard deviation from a dataset.

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    Percentile

    Find the value at any percentile rank in your dataset.

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    Correlation

    Calculate Pearson correlation coefficient (r) and R² for two datasets.

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    Linear Regression

    Calculate linear regression slope, intercept and R² to predict values.

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    Quartiles

    Calculate Q1, Q2, Q3, IQR and five-number summary for any dataset.

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    A/B Test🔥

    Test statistical significance of your A/B test results with p-value and confidence interval.

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    Margin of Error

    Calculate survey margin of error and confidence intervals based on sample size.

    All Statistics Calculators (24)

    📊T-Test📉Variance📈Percentile📐Correlation📉Linear Regression🎲Binomial Distribution📊Quartiles🎯Expected Value📋Frequency Distribution🔬Odds Ratio🧪A/B Test📊ANOVA📏Effect Size±Margin of Error💪Power Analysis🎲Poisson🔄Spearman ρ🤝Cohen's κ📐Standard Error∛Geometric Mean📊CV Calculator📊Descriptive Stats📊Box Plot📈Moving Average

    Descriptive Statistics

    Calculate mean, median, mode, standard deviation, variance, and range for any dataset. Our calculators handle both population and sample statistics with full step-by-step formulas.

    Hypothesis Testing

    Run one-sample and two-sample t-tests, chi-square tests, ANOVA, and p-value calculations. Perfect for academic research, A/B testing, and data science projects.

    Probability Distributions

    Calculate probabilities for normal, binomial, Poisson, and other distributions. Find z-scores, percentiles, and critical values for any significance level.

    Regression & Correlation

    Compute Pearson correlation coefficients, linear regression equations, and R-squared values to understand relationships between variables.

    Statistics Calculators Guides

    All Guides →
    What Is Standard Deviation? Formula & Interpretation Guide
    Understand standard deviation with clear explanations, formulas for population and sample SD, worked examples, and real-world applications.
    What Is a Z-Score? Formula, Examples & How to Use It
    Learn what z-scores are, how to calculate them, and how they're used in statistics, finance, and education to compare data across distributions.
    Statistics Basics Explained – Mean, Median, Mode & SD
    Learn statistics basics: mean, median, mode, variance, and standard deviation. Clear formulas, examples, and a free statistics calculator.
    How to Calculate Standard Deviation – Step-by-Step
    Learn to calculate standard deviation by hand and understand what it means. Includes population vs sample formulas and worked examples.
    How to Calculate Mean, Median, and Mode
    Step-by-step calculations for mean, median, and mode. Includes weighted mean, geometric mean, and when to use each measure.
    How to Calculate Z-Score – Standard Score Guide
    Compute Z-scores by hand: Z = (x − μ) / σ. Learn what Z-scores mean, how to read a Z-table, and use cases in stats and finance.

    Popular Statistics Calculators Calculations

    Frequently searched calculations — answered instantly with formulas and step-by-step explanations.

    Standard deviation of a datasetZ-score calculatorMean, median and mode calculatorPearson correlation coefficientNormal distribution probabilityChi-square test calculator

    Statistics Calculators Formula Reference

    All Formulas →
    Standard Deviation Formula – Population & SampleZ-Score Formula – Standard Score CalculationMean Formula – How to Calculate the AverageProbability Formula – Basic Probability CalculationMedian Formula – How to Find the Middle ValueVariance Formula – StatisticsMean, Median & Mode Formulas – Central Tendency Explained

    Frequently Asked Questions

    How do I calculate standard deviation?▼
    Standard Deviation (σ) = √[Σ(xᵢ − μ)² / N] for population, or √[Σ(xᵢ − x̄)² / (n−1)] for sample. Our calculator accepts a comma-separated list of values and returns mean, variance, and SD instantly.
    What is a p-value and what does p < 0.05 mean?▼
    A p-value is the probability of observing results as extreme as yours if the null hypothesis is true. P < 0.05 means there is less than a 5% chance the result occurred by random chance — the conventional threshold for statistical significance.
    How do I calculate a z-score?▼
    Z = (X − μ) ÷ σ, where X is the observed value, μ is the population mean, and σ is the standard deviation. A z-score of +2 means the value is 2 standard deviations above the mean.
    How do I calculate a confidence interval?▼
    CI = x̄ ± Z × (σ ÷ √n), where x̄ is the sample mean, Z is the critical value (1.96 for 95%), σ is standard deviation, and n is sample size. A 95% CI means 95% of similarly constructed intervals will contain the true population mean.
    What is the difference between correlation and causation?▼
    Correlation measures the strength of a linear relationship between two variables (r = −1 to +1). Causation means one variable directly causes changes in another. Two variables can be highly correlated without either causing the other — always interpret correlation in context.
    ✓ Documented formulas — all tools use standard industry formulas✓ Updated regularly — content reviewed 2026✓ Used by thousands daily✓ Free — no sign-up required

    See also

    🔢 Mathematics💰 Finance❤️ Health