Statistics & Data Analysis

Statistics Calculator

Calculate comprehensive summary statistics, dataset mean, median, sample standard deviation, variance, SEM, and range.

Statistics & Data Analysis

Mean Calculator

Calculate arithmetic mean (average), total dataset sum, number of observations (N), minimum, maximum, and standard error.

Statistics & Data Analysis

Median Calculator

Calculate dataset median (middle 50th percentile value), lower quartile Q1, upper quartile Q3, and Interquartile Range (IQR).

Statistics & Data Analysis

Mode Calculator

Calculate most frequent modal values, unimodal, bimodal, and multimodal dataset frequencies, occurrence counts, and distributions.

Statistics & Data Analysis

Mean, Median & Mode Calculator

Calculate central tendency measures, dataset mean, median, mode, range, sample variance, and standard deviation.

Statistics & Data Analysis

Range Calculator

Calculate total dataset range (Max - Min), minimum value, maximum value, midrange, and observation count (N).

Statistics & Data Analysis

Midrange Calculator

Calculate dataset midrange value (Max + Min) / 2, minimum value, maximum value, and total range spread.

Statistics & Data Analysis

Weighted Mean Calculator

Calculate weighted average for course grades, academic GPA, portfolio stock returns, and weighted datasets.

Statistics & Data Analysis

Weighted Average Calculator

Calculate weighted average scores for school grades, inventory unit costs, financial investments, and weighted survey responses.

Statistics & Data Analysis

Geometric Mean Calculator

Calculate geometric mean, CAGR compounding growth rates, and log-transformed averages for positive numbers.

Statistics & Data Analysis

Harmonic Mean Calculator

Calculate harmonic mean, average speed across equal distances, unit rate averages, and price-to-earnings (P/E) ratios.

Statistics & Data Analysis

Root Mean Square Calculator

Calculate Root Mean Square (RMS), quadratic mean, AC electrical effective voltage, crest factor, and mean absolute value.

Statistics & Data Analysis

Variance Calculator

Calculate sample variance (s2), population variance (sigma2), sum of squared deviations (SS), mean, and standard deviation.

Statistics & Data Analysis

Standard Deviation Calculator

Calculate sample standard deviation (s), population standard deviation (sigma), variance, coefficient of variation (CV %), and SEM.

Statistics & Data Analysis

Population Standard Deviation Calculator

Calculate population standard deviation (sigma), population variance (sigma2), sum of squares (SS), and population mean.

Statistics & Data Analysis

Sample Standard Deviation Calculator

Calculate sample standard deviation (s), sample variance (s2), degrees of freedom (df = n-1), and SEM.

Statistics & Data Analysis

Population Variance Calculator

Calculate population variance (sigma2), population standard deviation (sigma), sum of squares (SS), and population mean.

Statistics & Data Analysis

Sample Variance Calculator

Calculate sample variance (s2), sample standard deviation (s), degrees of freedom (df = n-1), and sample mean.

Statistics & Data Analysis

Coefficient of Variation Calculator

Calculate Coefficient of Variation (CV %), Relative Standard Deviation (RSD), mean, and variability risk levels.

Statistics & Data Analysis

Quartile Calculator

Calculate First Quartile (Q1), Second Quartile (Q2 Median), Third Quartile (Q3), and Interquartile Range (IQR).

Statistics & Data Analysis

Percentile Calculator

Calculate any k-th percentile value (Pk), median (P50), quartiles (Q1, Q3), and linear interpolation ranks.

Statistics & Data Analysis

Percentile Rank Calculator

Calculate percentile rank percentage for test scores, academic rankings, and Z-score equivalents.

Statistics & Data Analysis

Quartile Deviation Calculator

Calculate Quartile Deviation (QD), Semi-Interquartile Range, Coefficient of Quartile Deviation, and IQR.

Statistics & Data Analysis

Interquartile Range Calculator

Calculate Interquartile Range (IQR = Q3 - Q1), Tukey outlier fences (1.5 x IQR), quartiles, and detect statistical outliers.

Statistics & Data Analysis

Five Number Summary Calculator

Calculate five-number summary [Min, Q1, Median Q2, Q3, Max], Interquartile Range (IQR), and boxplot parameters.

Statistics & Data Analysis

Z-Score Calculator

Calculate standardized Z-scores, cumulative normal distribution probabilities, percentiles, and two-tailed p-values.

Statistics & Data Analysis

Z Score from Mean Calculator

Calculate Z-score = (X - mean) / SD, distance from mean, percentile rank %, and normal distribution probabilities.

Statistics & Data Analysis

Z Table Calculator

Standard Normal Distribution Z-Table lookup for P(Z < z), right tail P(Z > z), central area, and two-tailed p-values.

Statistics & Data Analysis

T Score Calculator

Calculate Student t-statistic, psychometric T-score (50 + 10Z), degrees of freedom df, and SEM.

Statistics & Data Analysis

T Distribution Calculator

Calculate Student t-distribution probabilities, one-tailed and two-tailed p-values, and degrees of freedom df.

Statistics & Data Analysis

Normal Distribution Calculator

Calculate normal bell curve probabilities P(X < x), density f(x), Z-score, and percentiles for N(mean, sigma2).

Statistics & Data Analysis

Normal Distribution Probability Calculator

Calculate normal distribution interval probability P(a < X < b), lower and upper Z-scores, and population area percentages.

Statistics & Data Analysis

Standard Normal Distribution Calculator

Calculate Standard Normal Distribution N(0,1) bell curve probabilities Phi(z), probability density phi(z), and upper tails.

Statistics & Data Analysis

Binomial Distribution Calculator

Calculate binomial probability P(X = k) = nCr * p^k * (1-p)^(n-k), cumulative P(X <= k), mean np, and variance.

Statistics & Data Analysis

Poisson Distribution Calculator

Calculate Poisson event probability P(X = k) = (lambda^k * e^-lambda) / k!, cumulative P(X <= k), mean lambda, and variance.

Statistics & Data Analysis

Geometric Distribution Calculator

Calculate geometric probability P(X = k) = (1-p)^(k-1) * p for first success on trial k, expected trials 1/p, and variance.

Statistics & Data Analysis

Hypergeometric Distribution Calculator

Calculate sampling without replacement probability P(X = k), expected mean, and finite population variance.

Statistics & Data Analysis

Exponential Distribution Calculator

Calculate continuous waiting time CDF P(X <= x) = 1 - e^(-lambda*x), survival P(X > x), mean 1/lambda, and median.

Statistics & Data Analysis

Uniform Distribution Calculator

Calculate continuous uniform probabilities P(X <= x) = (x-a)/(b-a), density f(x) = 1/(b-a), mean, and variance.

Statistics & Data Analysis

Probability Calculator

Calculate event probability P(A) = n(A) / n(S), complement P(A-complement), percentage %, and odds ratios.

Statistics & Data Analysis

Conditional Probability Calculator

Calculate P(A|B) = P(A and B) / P(B), joint probability, and test event independence.

Statistics & Data Analysis

Bayes Theorem Calculator

Calculate posterior probability P(A|B) = [P(B|A)*P(A)] / P(B), total evidence, and Bayesian probability updating.

Statistics & Data Analysis

Probability of Independent Events Calculator

Calculate P(A and B) = P(A)*P(B), union P(A or B), neither event, and exactly one event probabilities.

Statistics & Data Analysis

Probability of Dependent Events Calculator

Calculate P(A and B) = P(A) * P(B|A), sampling without replacement, and dependent event chains.

Statistics & Data Analysis

Odds Calculator

Calculate odds for ratio P/(1-P), odds against (1-P)/P, decimal odds, and fractional betting odds.

Statistics & Data Analysis

Odds to Probability Calculator

Convert betting odds ratio a:b to implied win probability P = a / (a + b), percentage %, and decimal odds.

Statistics & Data Analysis

Probability to Odds Calculator

Convert win probability P to odds for ratio P/(1-P), odds against, decimal, and American odds.

Statistics & Data Analysis

Permutation Calculator

Calculate permutations P(n, r) = n! / (n - r)!, permutations with repetition n^r, circular permutations (n-1)!, and combinations.

Statistics & Data Analysis

Combination Calculator

Calculate combinations C(n, r) = n! / [r!(n-r)!], combinations with repetition C(n+r-1, r), and Pascal triangle coefficients.

Statistics & Data Analysis

Factorial Calculator

Calculate integer factorial n!, double factorial n!!, Stirling approximation, and digit counts for 0 <= n <= 170.

Statistics & Data Analysis

One Sample t Test Calculator

Calculate one-sample t-statistic t = (x-bar - mu0)/(s/sqrt(n)), degrees of freedom df, p-value, and 95% confidence intervals.

Statistics & Data Analysis

Two Sample t Test Calculator

Calculate Welch t-statistic for independent samples, mean difference (x-bar1 - x-bar2), df, p-value, and 95% CI.

Statistics & Data Analysis

Paired t Test Calculator

Calculate dependent paired t-statistic t = d-bar/(s_d/sqrt(n)), before-after mean differences, df, p-value, and 95% CI.

Statistics & Data Analysis

One-Way ANOVA Calculator

Calculate F-statistic F = MSB / MSW, degrees of freedom df1, df2, p-value, and eta squared effect size.

Statistics & Data Analysis

Two-Way ANOVA Calculator

Calculate main effects FA, FB, interaction effect FAB, MSE, degrees of freedom, and two-factor factorial ANOVA.

Statistics & Data Analysis

Chi-Square Calculator

Calculate chi-square statistic, degrees of freedom df, p-value, and critical significance thresholds.

Statistics & Data Analysis

Chi-Square Goodness of Fit Calculator

Calculate goodness-of-fit chi2 = sum((Oi - Ei)^2 / Ei), degrees of freedom df = k-1, p-value, and Cramer V effect size.

Statistics & Data Analysis

Chi-Square Test of Independence Calculator

Calculate 2x2 contingency table chi-square, Yates correction, odds ratio OR = ad/bc, phi coefficient, and p-value.

Statistics & Data Analysis

Z Test Calculator

Calculate Z-statistic Z = (x-bar - mu0)/(sigma/sqrt(n)), known population SD sigma, p-value, and 95% confidence intervals.

Statistics & Data Analysis

One Sample Z Test Calculator

Calculate one-sample Z = (x-bar - mu0)/(sigma/sqrt(n)), margin of error, p-value, and 95% confidence interval.

Statistics & Data Analysis

Two Sample Z Test Calculator

Calculate two-sample Z-statistic, mean difference (x-bar1 - x-bar2), standard error, p-value, and 95% CI.

Statistics & Data Analysis

Z Test for Single Proportion Calculator

Calculate one-proportion Z-statistic Z = (pHat - p0)/sqrt(p0(1-p0)/n), sample proportion pHat, p-value, and 95% CI.

Statistics & Data Analysis

Z Test for Two Proportions Calculator

Calculate two-proportion Z-statistic, proportion difference (pHat1 - pHat2), pooled proportion, p-value, and 95% CI.

Statistics & Data Analysis

Pearson Correlation Calculator

Calculate Pearson correlation coefficient r, R-squared coefficient of determination, t-statistic, p-value, and covariance.

Statistics & Data Analysis

Spearman Rank Correlation Calculator

Calculate Spearman rank correlation coefficient rho = 1 - (6sum(d2)/(n(n2-1))), rank differences, t-statistic, and p-value.

Statistics & Data Analysis

Covariance Calculator

Calculate sample covariance Cov(X,Y) = sum((x-xBar)(y-yBar))/(n-1), population covariance sigma_XY, and Pearson correlation.

Statistics & Data Analysis

Simple Linear Regression Calculator

Calculate least squares slope beta1, intercept beta0, linear regression equation yHat = beta0 + beta1*x, R2, and Y predictions.

Statistics & Data Analysis

Multiple Linear Regression Calculator

Calculate multiple regression R-squared, adjusted R-squared, overall model F-statistic, and residual degrees of freedom.

Statistics & Data Analysis

R-Squared Calculator

Calculate coefficient of determination R2 = SSR / SST, explained variance %, unexplained error %, and sum of squares.

Statistics & Data Analysis

Adjusted R-Squared Calculator

Calculate adjusted R2 = 1 - [(1-R2)(N-1)/(N-k-1)], predictor penalty, and multiple regression model comparison.

Statistics & Data Analysis

Confidence Interval for Mean Calculator

Calculate 90%, 95%, 99% confidence interval [xBar +- z*(s/sqrt(n))], margin of error, and SEM.

Statistics & Data Analysis

Confidence Interval for Proportion Calculator

Calculate 90%, 95%, 99% proportion confidence interval [pHat +- z*sqrt(pHat(1-pHat)/n)], margin of error %, and sample size.

Statistics & Data Analysis

Confidence Interval for Difference Between Means Calculator

Calculate 90%, 95%, 99% CI [(xBar1-xBar2) +- z*SE], mean difference, and margin of error.

Statistics & Data Analysis

Confidence Interval for Difference Between Proportions Calculator

Calculate 90%, 95%, 99% CI [(pHat1-pHat2) +- z*SE], proportion difference %, and A/B test margin of error.

Statistics & Data Analysis

Margin of Error Calculator

Calculate margin of error ME = z*(s/sqrt(n)), confidence level z*, standard error, and sample size requirements.

Statistics & Data Analysis

Cohens d Calculator

Calculate standardized effect size d = (xBar1 - xBar2)/s_pooled, Hedges g, Glass delta, and Cohen effect magnitude rating.

Statistics & Data Analysis

Relative Risk Calculator

Calculate relative risk RR = [a/(a+b)] / [c/(c+d)], 95% CI, absolute risk reduction ARR, and relative risk reduction RRR.

Statistics & Data Analysis

Odds Ratio Calculator

Calculate odds ratio OR = (ad)/(bc), 95% CI, case-control odds, and logistic regression odds ratios.

Statistics & Data Analysis

Mann-Whitney U Test Calculator

Calculate non-parametric Mann-Whitney U, Wilcoxon rank sum R1, R2, Z approximation, and p-value.

Statistics & Data Analysis

Wilcoxon Signed-Rank Test Calculator

Calculate non-parametric paired Wilcoxon W, W+ positive ranks sum, W- negative ranks sum, Z approximation, and p-value.

Statistics & Data Analysis

Kruskal-Wallis Test Calculator

Calculate Kruskal-Wallis H statistic H = [12/(N(N+1))] * sum(Ri^2/ni) - 3(N+1), degrees of freedom df = k-1, and p-value.

Statistics & Data Analysis

Simple Moving Average Calculator

Calculate Simple Moving Average SMA = (P1 + P2 + ... + Pn) / n over any custom time series window.

Statistics & Data Analysis

Weighted Moving Average Calculator

Calculate Weighted Moving Average WMA = sum(wi * Pi) / sum(wi) assigning higher weights to recent observations.

Statistics & Data Analysis

Exponential Smoothing Calculator

Calculate Single Exponential Smoothing forecast S_t = alpha * Y_t + (1-alpha) * S_{t-1} with smoothing constant alpha.

Statistics & Data Analysis

Standard Error Calculator

Calculate Standard Error of the Mean SEM = s / sqrt(n), margin of error, and confidence precision.

Statistics & Data Analysis

Sum of Squares Calculator

Calculate Total Sum of Squares SS = sum((x - mean)^2), mean, variance, and sample standard deviation.

Statistics & Data Analysis

Root Mean Square Error (RMSE) Calculator

Calculate Root Mean Square Error RMSE = sqrt( (1/n) * sum((y_actual - y_pred)^2) ) for predictive model evaluation.

Statistics & Data Analysis

Mean Absolute Error (MAE) Calculator

Calculate Mean Absolute Error MAE = (1/n) * sum(|y_actual - y_pred|) for model prediction performance.

Statistics & Data Analysis

Mean Absolute Percentage Error (MAPE) Calculator

Calculate Mean Absolute Percentage Error MAPE = (100%/n) * sum(|(actual - pred)/actual|) for forecast accuracy.

Statistics & Data Analysis

Pooled Variance Calculator

Calculate Pooled Variance s_p^2 = [(n1-1)s1^2 + (n2-1)s2^2] / (n1 + n2 - 2) for two-sample t-tests.

Statistics & Data Analysis

Pooled Standard Deviation Calculator

Calculate Pooled Standard Deviation s_p = sqrt( [ (n1-1)s1^2 + (n2-1)s2^2 ] / (n1+n2-2) ) for effect size scaling.

Statistics & Data Analysis

F-Test for Equality of Variances Calculator

Calculate F-test ratio F = s1^2 / s2^2 (larger variance / smaller variance), df1, df2, and variance ratio significance.

Statistics & Data Analysis

Levenes Test Calculator

Calculate Levenes Test for Homogeneity of Variances across group absolute deviation medians.

Statistics & Data Analysis

Number Needed to Treat (NNT) Calculator

Calculate Number Needed to Treat NNT = 1 / ARR (Absolute Risk Reduction) for clinical treatment trials.

Statistics & Data Analysis

Absolute Risk Reduction (ARR) Calculator

Calculate Absolute Risk Reduction ARR = Control Risk - Treatment Risk, percentage point risk difference, and NNT.

Statistics & Data Analysis

Relative Risk Reduction (RRR) Calculator

Calculate Relative Risk Reduction RRR = (Control Risk - Treatment Risk) / Control Risk = 1 - RR.

Statistics & Data Analysis

Sensitivity and Specificity Calculator

Calculate Diagnostic Sensitivity = TP/(TP+FN), Specificity = TN/(TN+FP), Accuracy, and Youden J index.

Statistics & Data Analysis

Positive Predictive Value (PPV) Calculator

Calculate Positive Predictive Value PPV = TP / (TP + FP) and post-test disease probability.

Statistics & Data Analysis

Negative Predictive Value (NPV) Calculator

Calculate Negative Predictive Value NPV = TN / (TN + FN) and post-test healthy confidence.

Statistics & Data Analysis

Likelihood Ratio Calculator

Calculate Positive Likelihood Ratio LR+ = Sens/(1-Spec) and Negative Likelihood Ratio LR- = (1-Sens)/Spec.

Statistics & Data Analysis

Sample Size Calculator

Determine minimum sample size required for survey research based on confidence level, margin of error, and population size.