5-Number Summary Calculator
Calculate the five-number summary (min, Q1, median, Q3, max) with IQR, outlier detection, box plot visualization, decile table, and Bowley skewness for any dataset.
Free Statistics Calculators
158 toolsAnalyze data with calculators for mean, median, standard deviation, probability, distributions, regression, confidence intervals, and hypothesis tests.
Descriptive
22 calculatorsMean, median, mode, range, variance, and standard deviation calculators.
Ascending Order Calculator
Sort numbers in ascending or descending order with ranks, percentile ranks, gap analysis, frequency counts, and number line visualization. Handles ties with average ranking.
Box Plot Calculator
Generate box-and-whisker plots with five-number summary, Tukey fences, outlier detection, percentile table, and Bowley skewness. Interactive SVG visualization.
Coefficient of Variation Calculator
Calculate the coefficient of variation (CV) for one or two datasets, with comparison mode, CV gauge, reference table, and detailed calculation steps.
Covariance Calculator
Calculate covariance, Pearson correlation, R², and regression line for paired data. Includes scatter plot, cross-product table, and correlation gauge.
First Quartile (Q1) Calculator
Calculate the first quartile (Q1, 25th percentile) with three methods: inclusive, exclusive, and interpolated. Compare methods, view percentile table, and sorted data.
Frequency Distribution Calculator
Build grouped and ungrouped frequency distribution tables with histograms, cumulative frequencies, relative frequencies, and class count rule comparison.
Frequency Polygon Calculator
Create frequency polygons with SVG visualization, cumulative ogive overlay, class frequency table, polygon coordinates, and automatic class interval selection.
Histogram Calculator
Generate histograms from raw data with 5 bin methods (Sturges, Square Root, Rice, Freedman-Diaconis, custom). SVG visualization, density, skewness, and bin comparison.
Interquartile Range (IQR) Calculator
Calculate IQR, semi-IQR, quartile coefficient of dispersion, Tukey fences, and outlier detection. Includes box plot, quartile segments, and IQR vs SD comparison.
Mean, Median, Mode Calculator
Calculate arithmetic, geometric, harmonic, trimmed, and weighted means plus median, mode, and modality. Includes frequency table, skewness, and visual comparison.
Median Absolute Deviation (MAD) Calculator
Calculate MAD, scaled MAD, mean absolute deviation, and MAD-based outlier detection. Compare robust vs classical spread measures with visual breakdown.
Midrange Calculator
Calculate the midrange (average of min and max), midhinge, trimean, and deviation analysis. Compare midrange to mean, median, and robust center measures.
Outlier Calculator
Detect outliers using IQR/Tukey fences, Z-score, modified Z-score (MAD), Grubbs, and Dixon Q tests. Visual outlier zones, method comparison, and full data analysis.
Percentile Rank Calculator
Find the percentile rank of a score in a dataset, compute custom percentile values, and compare exclusive/inclusive/mean methods. Includes gauge, decile table, and Z-score.
Population Variance Calculator
Calculate population variance (σ²), sample variance (s²), standard deviation, sum of squares, Bessel correction, and CV. Includes deviation table and computation methods.
Quartile Calculator
Calculate Q1, Q2 (median), Q3, IQR, midhinge, trimean, and five-number summary using 3 quartile methods. Box plot, method comparison, and decile table included.
Relative Frequency Calculator
Calculate relative frequency, cumulative frequency, percentages, and Shannon entropy from ungrouped data. Includes bar chart, ogive curve, and frequency distribution table.
Skewness Calculator
Calculate skewness, kurtosis, and shape metrics from data using Fisher, Pearson, Bowley, and Kelly methods. Includes skewness gauge, method comparison, and significance testing.
Standard Deviation Calculator
Calculate standard deviation, variance, mean, median, quartiles, IQR, confidence intervals, z-scores, skewness, and outliers. Visual box plot, frequency distribution with bars, and preset data sets.
Stem-and-Leaf Plot Calculator
Generate stem-and-leaf plots with frequency counts, back-to-back comparison mode, key interpretation, and summary statistics. Auto-detects stem unit.
Third Quartile (Q3) Calculator
Calculate the third quartile (Q3/75th percentile) using exclusive, inclusive, and interpolated methods. Includes quartile number line, method comparison, derived measures, and percentile table.
Probability
25 calculatorsProbability, permutation, combination, and Bayes theorem calculators.
6-Sided Dice Probability Calculator
Calculate exact probabilities for rolling 6-sided dice — sums, specific values, at-least-one conditions, and repeated trial outcomes with distribution tables.
AND Probability Calculator
Calculate the probability of two or three events both occurring — independent or dependent — with breakdowns, odds, and repeated trial analysis.
Bayes' Theorem Calculator
Apply Bayes' theorem to update probabilities with new evidence — compute posterior probability, likelihood ratios, and confusion matrices for medical tests.
Beta Distribution Calculator
Compute PDF, CDF, mean, mode, variance, and percentiles for the beta distribution with interactive shape parameter presets and visual curve.
Binomial Distribution Calculator
Calculate binomial probabilities, cumulative distribution, mean, variance, and confidence intervals for any number of trials and success probability.
Birthday Paradox Calculator
Calculate the surprising probability that two or more people in a group share a birthday — with tables, visual bars, and customizable year length.
Central Limit Theorem Calculator
Explore the Central Limit Theorem — compute standard error, z-scores, confidence intervals, and see how sample size affects the sampling distribution.
Coin Flip Probability Calculator
Calculate the probability of getting a specific number of heads or tails in coin flips — exact, cumulative, streaks, and distribution tables.
Conditional Probability Calculator
Calculate P(A|B) and P(B|A) from joint, marginal, or conditional inputs — with contingency tables, independence tests, and lift analysis.
Exponential Distribution Calculator
Compute PDF, CDF, percentiles, and reliability statistics for the exponential distribution with interactive rate parameter and visual density curve.
Hypergeometric Distribution Calculator
Calculate exact hypergeometric probabilities for sampling without replacement, with PMF, CDF, distribution tables, and binomial approximation comparison.
Implied Probability Calculator
Convert American, decimal, and fractional betting odds to implied probability with EV analysis, Kelly criterion, edge visualization, and vig breakdown.
Joint Probability Calculator
Calculate joint, union, and conditional probabilities for two events, with contingency tables, Venn diagram visualization, lift analysis, and repeated-event chains.
Lognormal Distribution Calculator
Compute PDF, CDF, percentiles, and moments for the lognormal distribution with interactive density curve, percentile table, and properties reference.
Monty Hall Problem Calculator
Explore the Monty Hall problem with analytical probabilities and Monte Carlo simulation for 3+ doors, variable reveals, and strategy comparison visuals.
Negative Binomial Distribution Calculator
Calculate negative binomial probabilities — failures before the r-th success — with full distribution table, visual chart, and parameter sensitivity analysis.
Normal Distribution & Sampling Calculator
Compute normal distribution probabilities, z-scores, and sampling distributions with visual comparison of population vs sample mean curves and confidence intervals.
OR Probability Calculator
Calculate P(A or B) for mutually exclusive, non-exclusive, and three-event scenarios with stacked probability bars, comparison tables, and repeated-trial analysis.
Post-Test Probability Calculator
Calculate post-test probability from sensitivity, specificity, and prevalence with likelihood ratios, confusion matrix, sequential testing, and PPV/NPV sensitivity analysis.
Probability Fraction Calculator
Convert probability fractions to decimals, percentages, and odds. Simplify fractions, combine probabilities, compute binomial distribution over trials, and view equivalent fractions.
Probability of Three Events Calculator
Calculate combined probability of three events using inclusion-exclusion. Supports independent and dependent events with Venn diagram regions, conditional probabilities, and repeated trials.
Two Dice Probability Calculator
Calculate two-dice probabilities for sums, doubles, products, and differences. View complete sum distribution, outcome grid, cumulative probabilities, and custom-sided dice support.
Uniform Distribution Calculator
Calculate probabilities, percentiles, and statistics for continuous and discrete uniform distributions. Includes PDF/CDF visualization, quantile table, order statistics, and sampling distribution.
Venn Diagram Calculator
Calculate Venn diagram regions for 2 or 3 sets. Find unions, intersections, complements, conditional probabilities, Jaccard similarity, and all exclusive regions with visual diagrams.
Weibull Distribution Calculator
Calculate Weibull distribution PDF, CDF, survival, hazard rate, MTTF, percentiles, and B-life. Supports reliability analysis with shape and scale parameters plus mission time planning.
Normal, binomial, Poisson, chi-square, and t-distribution calculators.
Calculators coming soon.
Inference
10 calculatorsConfidence interval, hypothesis test, p-value, and sample size calculators.
ANOVA Calculator
Perform one-way ANOVA analysis online. Compute F statistic, p-value, eta-squared, omega-squared, and full ANOVA table with group summaries and visual comparison.
Bonferroni Correction Calculator
Calculate adjusted significance thresholds for multiple comparisons using Bonferroni, Šidák, and Holm corrections. Compare methods side-by-side with FWER tables.
Chi-Square Test Calculator
Perform chi-square goodness-of-fit and independence tests online. Get χ² statistic, p-value, Cramér's V, expected frequencies, and standardized residuals.
Fisher's Exact Test Calculator
Perform Fisher's exact test on 2×2 contingency tables. Calculate exact p-value, odds ratio, relative risk, and view every possible table in the hypergeometric distribution.
McNemar's Test Calculator
Perform McNemar's test for paired binary data. Compute chi-square statistic, exact binomial p-value, odds ratio, and compare correction methods on matched pairs.
P-Value Calculator
Calculate p-values from z, t, chi-square, or F statistics. Supports two-tailed, left-tail, and right-tail tests with significance at multiple alpha levels.
Power Analysis Calculator
Calculate required sample size, achieved power, and Type II error for z-tests, t-tests, and chi-square tests. Cohen's d effect size reference and power curves included.
T-Test Calculator
Perform one-sample, two-sample, Welch's, and paired t-tests online. Get t statistic, p-value, degrees of freedom, Cohen's d, and confidence intervals quickly.
Wilcoxon Rank-Sum Test Calculator
Perform the Wilcoxon rank-sum (Mann-Whitney U) test for non-parametric comparison of two groups. Get U statistic, z-score, p-value, effect size, and rank table.
Z-Test Calculator
Perform one-sample, two-sample, and proportion z-tests online. Calculate z statistic, p-value, confidence intervals, and compare against critical values.
Regression
13 calculatorsLinear regression, correlation, R-squared, and curve fitting calculators.
Coefficient of Determination (R²) Calculator
Calculate R², adjusted R², SS decomposition (SST/SSR/SSE), F-statistic, standard error, and residual analysis. Full ANOVA decomposition with interpretation guide.
Correlation Calculator
Calculate Pearson and Spearman correlation coefficients, R², covariance, significance testing, z-scores, and ranks from X/Y data. Full statistical analysis.
Cubic Regression Calculator
Fit Y = aX³ + bX² + cX + d with R², inflection point, critical points, end behavior analysis, and residual table. Comparison to linear fit.
Exponential Growth Prediction Calculator
Predict future values with exponential growth/decay. Doubling time, half-life, Rule of 70, milestone table, growth trajectory, discrete & continuous compounding.
Exponential Regression Calculator
Fit Y = ae^(kx) or Y = abˣ with R², doubling time/half-life, growth rate, log-scale residuals, and growth projection table.
Linear Regression Calculator
Calculate the best-fit line (OLS), slope, intercept, R², correlation, residuals, and prediction confidence intervals from X/Y data points.
Matthews Correlation Coefficient (MCC) Calculator
Calculate MCC from confusion matrix with full metrics: accuracy, F1, precision, recall, specificity, Cohen's kappa, informedness, markedness, and visual confusion matrix.
Pearson Correlation Calculator
Calculate Pearson's r with step-by-step computation, Fisher z confidence intervals, t-test significance, covariance, and full deviation table.
Polynomial Regression Calculator
Fit polynomials of any degree (1-8) with R², adjusted R², AIC/BIC, coefficient table, residuals, and automatic degree comparison for model selection.
Quadratic Regression Calculator
Fit Y = aX² + bX + c to data with R², vertex, roots, discriminant, residual analysis, and comparison to linear fit.
Quartic Regression Calculator
Fit a fourth-degree polynomial (Y=aX⁴+bX³+cX²+dX+e) with R², critical points, inflection points, ANOVA, residuals, and degree comparison.
Residual Analysis Calculator
Compute residuals, standardized residuals, leverage, Cook's distance, Durbin-Watson, skewness, kurtosis, and outlier detection for regression diagnostics.
Spearman's Rank Correlation Calculator
Calculate Spearman's ρ with rank table, tie correction, t-test significance, Σd² breakdown, and Spearman vs Pearson comparison.
Dice & Random
16 calculatorsDice rollers, coin flippers, lottery, and random number generators.
10-Sided Dice Roller
Roll d10 dice online with customizable count, modifiers, keep highest/lowest, and exploding dice. Perfect for RPGs, percentile rolls, and probability games.
2 Dice Roller
Roll two dice online with adjustable sides, modifiers, drop highest/lowest, and target checks. Full sum distribution and doubles tracking included.
4-Sided Dice Roller
Roll d4 dice online with modifiers, keep highest/lowest, reroll 1s, and preset configurations. Track face frequency and review full roll history.
6-Sided Dice Roller
Roll d6 dice online with presets for 1d6–8d6, modifiers, keep highest/lowest, reroll 1s, and full face distribution charts. Perfect for board games and RPGs.
Coin Flip Streak Calculator
Simulate coin flips and analyze streaks. Find the longest heads/tails run, streak distributions, and compare observed results to mathematical expectations.
Coin Flipper
Flip a coin up to 10,000 times with adjustable bias. Track heads/tails counts, streaks, z-scores, running percentages, and alternation rates.
Custom Dice Roller
Roll any dice configuration from d2 to d1000 with modifiers, keep modes, exploding dice, and minimum face values. Full statistical analysis and frequency charts.
D&D Dice Roller
Dungeons & Dragons dice roller with advantage/disadvantage, attack vs AC, damage combos, critical hit detection, and full D&D DC/dice reference tables.
d100 Dice Roller
Roll d100 (percentile) dice online with standard or two-d10 percentile mode. Includes success threshold checks, critical hits/fails, and decile distribution.
d20 Dice Roller
Roll d20 dice with advantage/disadvantage, modifiers, DC checks, natural 20/1 tracking, and face frequency analysis. The essential D&D dice roller.
Dice Average Calculator
Calculate expected averages, min/max, and standard deviation for any dice expression. Supports drop lowest, reroll, exploding dice, and modifiers.
Dice Calculator
Multi-group dice calculator supporting mixed dice types (d4+d6+d20), modifiers, take highest/lowest, and batch rolls. Build any dice expression for RPGs.
Dice Roller Calculator
Roll any number of dice with any sides online. Full roll history, sum distribution, face frequency analysis, and sorting options. The classic virtual dice roller.
Lottery Calculator
Calculate lottery odds, expected value, and prize probabilities for any lottery format. Generate random numbers and compare Powerball, Mega Millions, EuroMillions odds.
Random Dice Roller
Roll completely randomized dice — random count, random type, optional random modifier. Great for surprise encounters, writing prompts, and dice warm-ups.
Roulette Payout Calculator
Calculate roulette payouts, house edge, win probabilities, and expected value for every bet type. Simulate spins and compare American vs European wheels.
Sampling
8 calculatorsSample size, margin of error, standard error, and accuracy calculators.
Accuracy Calculator
Calculate accuracy, precision, recall, F1, MCC from a confusion matrix. Also computes measurement error metrics (MAE, RMSE, MAPE) and simple proportion accuracy with confidence intervals.
Constant of Proportionality Calculator
Find the constant of proportionality k from data pairs. Supports direct, inverse, squared, square root, and custom power models with R², residuals, and fit analysis.
Margin of Error Calculator
Calculate margin of error from sample data or find required sample size for a desired MOE. Supports proportions and means with finite population correction.
Sampling Distribution of Sample Proportion Calculator
Explore the sampling distribution of p̂. Calculate mean, standard error, probabilities, and quantiles. Visualize the bell curve with normal approximation conditions.
Sampling Error Calculator
Calculate sampling error (standard error and margin of error) for proportions and means. Includes finite population correction, error decomposition, and sample size comparison.
Sensitivity & Specificity Calculator
Calculate sensitivity, specificity, PPV, NPV, likelihood ratios, and Youden's J from a confusion matrix. Includes PPV/NPV table at different prevalence levels.
Specificity Calculator
Calculate specificity (true negative rate) from TP, FP, FN, TN. Includes false positive rate, confidence interval, prevalence-adjusted PPV table, and diagnostic metrics.
Standard Error Calculator
Calculate standard error for means, proportions, differences, or raw data. Includes margin of error, finite population correction, and SE vs sample size comparison.
Combinatorics
6 calculatorsCombinations, permutations, password complexity, and counting calculators.
Combinations with Repetition Calculator
Calculate multiset combinations C(n+r-1, r). Stars and bars visualization, full enumeration for small cases, distribution patterns, and reference tables.
Combinations without Repetition Calculator
Calculate C(n, r) combinations without repetition. Full enumeration for small cases, Pascal's triangle row, probability of a specific combo, and reference table.
Password Combination Calculator
Calculate password combinations, entropy bits, and brute-force crack time. Compare password length and character set impacts on security strength.
Permutations with Repetition Calculator
Calculate ordered arrangements with repetition (n^r). Supports variable pool sizes per position, position breakdown, entropy, and reference tables.
Permutations without Repetition Calculator
Calculate P(n, r) ordered arrangements without repetition. Step-by-step position filling, full enumeration, comparison with combinations, and reference table.
Possible Combinations Calculator
Calculate all four types of counting: permutations/combinations with/without repetition. Decision guide, side-by-side comparison, visual size chart, and common examples.
General
58 calculatorsGeneral statistics reference and utility calculators.
Absolute Uncertainty Calculator
Calculate absolute, relative, and expanded uncertainty for measurements and propagate errors through addition, subtraction, multiplication, division, and powers.
Benford's Law Calculator
Test whether a dataset follows Benford's Law using chi-squared, K-S, and MAD statistics. Visualize leading digit distribution against expected frequencies.
Bertrand Box Paradox Calculator
Explore the Bertrand box paradox with interactive probability calculations, visual box displays, coin-level analysis, and Monte Carlo simulation.
Bertrand Paradox Calculator
Explore Bertrand's paradox of random chords with three methods, inscribed polygon comparison, probability visualization, and Monte Carlo simulation.
Boy or Girl Paradox Calculator
Explore the boy-or-girl paradox with conditional probability for multiple scenarios, distribution tables, and Monte Carlo simulation verification.
Chebyshev's Theorem Calculator
Apply Chebyshev's inequality to find the minimum proportion of data within k standard deviations of the mean, with normal distribution comparison.
Class Width Calculator
Calculate class width for frequency distributions using Sturges', Scott's, Freedman-Diaconis, and Rice rules. Generate class intervals automatically.
Cohen's d Calculator
Calculate Cohen's d, Hedges' g, and Glass's Δ effect sizes with CLES, overlap metrics, confidence intervals, and benchmark interpretation tables.
Confusion Matrix Calculator
Compute accuracy, precision, recall, F1, MCC, kappa, and 15+ classification metrics from TP/FP/FN/TN values with visual matrix and performance bars.
Continuity Correction Calculator
Apply Yates continuity correction for binomial-to-normal and Poisson-to-normal approximations with exact comparison, z-scores, and CDF tables.
Critical Value Calculator
Find critical values for Z, t, chi-square, and F distributions by significance level and degrees of freedom with reference tables and rejection region visualization.
Decile Calculator
Calculate deciles (D1-D9) from any dataset with three interpolation methods, decile range analysis, distribution bars, and color-coded sorted data display.
Decimal Odds Calculator
Convert between decimal, fractional, and American odds formats with implied probability, payout tables, stake analysis, and a complete conversion reference chart.
Degrees of Freedom Calculator
Calculate degrees of freedom for t-tests, ANOVA, chi-square, regression, and Welch's test with step-by-step formulas and a comprehensive reference table.
Dispersion Calculator
Calculate range, variance, standard deviation, IQR, MAD, CV, skewness, and kurtosis from any dataset with deviation tables, visual spread plot, and outlier detection.
Dot Plot Calculator
Generate interactive dot plots from data with frequency distribution tables, cumulative frequencies, summary statistics, and sortable output options.
Empirical Rule Calculator (68-95-99.7)
Apply the 68-95-99.7 rule to normal distributions with bell curve visualization, section probabilities, z-score lookup, and Chebyshev comparison table.
Error Propagation Calculator
Propagate measurement uncertainties through addition, multiplication, powers, logarithms, and exponentials with error budget analysis and step-by-step derivations.
F-Statistic Calculator
Calculate the F-statistic with p-value, critical value, ANOVA summary table, effect sizes (eta-squared, omega-squared), and rejection region visualization.
False Positive Paradox Calculator
Demonstrate the false positive paradox (base rate fallacy) with visual breakdowns, PPV-prevalence curves, retest analysis, and strategies for resolving the paradox.
False Positive Rate Calculator
Calculate false positive rate, PPV, NPV, and 11 diagnostic metrics from prevalence, sensitivity, and specificity with confusion matrix and PPV-prevalence curve.
Five-Star Rating Calculator
Analyze star ratings with simple average, Bayesian average, Wilson confidence, distribution visualization, polarity detection, and entropy-based consensus metrics.
Fractional Odds Calculator
Convert between fractional, decimal, American odds and implied probability with payout tables, profit calculations, and a comprehensive odds reference chart.
Geometric Distribution Calculator
Calculate geometric distribution probabilities with PMF, CDF, waiting time tables, distribution visualization, and summary statistics for trials until first success.
Greatest to Least Calculator
Sort numbers from greatest to least with visual bar chart, ranked data table showing percentiles, gaps, deviations, and a five-number summary with IQR.
Index of Qualitative Variation (IQV) Calculator
Calculate IQV, Blau's index, Shannon entropy, and Gini coefficient for categorical data with distribution visualization and diversity measure comparisons.
Least to Greatest Calculator
Sort numbers from least to greatest with number line visualization, ranked data table with percentiles, gap analysis, outlier detection, and five-number summary.
Least to Greatest Decimals Calculator
Sort decimal numbers from least to greatest with precision analysis, fraction approximation, number line visualization, and gap analysis for scientific data.
Lower Fence Calculator
Calculate lower and upper fences for outlier detection using IQR method with box plot visualization, outlier classification, and clean-data impact analysis.
Mann-Whitney U Test Calculator
Perform Mann-Whitney U test (Wilcoxon rank-sum) with automatic ranking, tie correction, z-approximation, effect size, and detailed rank tables.
Moneyline Odds Calculator
Convert moneyline/American odds to decimal, fractional, and implied probability with payout tables, parlay builder, vig analysis, and common odds reference chart.
Normal Approximation Calculator
Use the normal approximation to the binomial distribution. Calculate probabilities, z-scores, and check validity conditions with continuity correction.
Odds Calculator
Convert between probability, odds for, odds against, decimal, fractional, and American odds. Includes expected value tables and comparisons.
Order from Least to Greatest Calculator
Sort numbers from least to greatest or greatest to least. Shows sorting steps, rank table, percentiles, number line, and position changes.
Ordering Decimals Calculator
Sort decimal numbers in ascending or descending order. Aligns decimal places, shows fraction approximations, gap analysis, and number line visualization.
Ordering Numbers Calculator
Sort any set of numbers in ascending or descending order. Shows rank tables, quartiles, odd/even breakdown, grouping, and frequency distribution.
P-Hat Calculator
Calculate the sample proportion (p-hat), standard error, confidence intervals (Wald and Wilson), margin of error, and required sample sizes.
Parrondo's Paradox Calculator
Simulate Parrondo's paradox: two losing games that produce a winning strategy when combined. Adjust probabilities and see trajectory results.
Pie Chart Angle Calculator
Calculate the exact angle in degrees for each slice of a pie chart. Shows start/end angles, arc lengths, mid-angles, and step-by-step formulas.
Pie Chart Calculator
Create pie charts from data with percentages, degree angles, SVG visualization, Herfindahl index, Shannon entropy, and cumulative breakdowns.
Pie Chart Percentage Calculator
Calculate percentages for pie chart slices from raw data. Includes Pareto analysis, cumulative percentages, variation metrics, and step-by-step formulas.
Point Estimate Calculator
Calculate point estimates for population mean, proportion, variance, and differences. Compare Wald, Wilson, Laplace, and Jeffreys estimators with confidence intervals.
Raw Score Calculator
Convert z-scores to raw scores using the population mean and standard deviation. Includes percentile lookup, distribution visualizer, and benchmark tables.
Rayleigh Distribution Calculator
Calculate PDF, CDF, quantiles, and moments for the Rayleigh distribution. Includes distribution visualization, survival function, hazard rate, and range probabilities.
Relative Error Calculator
Calculate absolute, relative, and percentage error between measured and actual values. Includes tolerance checking, error propagation, and visual comparison.
Relative Risk Calculator
Calculate relative risk, odds ratio, absolute risk difference, and NNT from a 2×2 contingency table. Includes 95% confidence intervals and chi-squared test.
Relative Standard Error (RSE) Calculator
Calculate the relative standard error, coefficient of variation, and quality rating for survey estimates. Includes confidence intervals and sample size planning.
Risk Calculator
Calculate expected loss, mitigation ROI, risk scores, and sensitivity analysis. Includes risk matrix, breakeven analysis, and visual risk gauge.
Sample Mean & Proportion Calculator
Calculate sample mean or proportion with standard error, confidence intervals, hypothesis testing, and sample size planning. Includes Wilson interval for proportions.
Shannon Entropy Calculator
Calculate Shannon entropy, evenness, redundancy, perplexity, KL divergence, and Rényi entropy spectrum for any categorical distribution. Supports bits, nats, and hartleys.
Simpson's Diversity Index Calculator
Calculate Simpson's Diversity Index, Shannon Index, evenness, richness, and Hill numbers for any categorical dataset. Includes visual distribution bars and detailed breakdown.
Sum of Squares Calculator
Calculate sum of squares (SS), variance, and ANOVA decomposition. Shows SS total, SS between, SS within, F-statistic, and detailed deviation breakdowns.
T-Statistic Calculator
Calculate t-statistic, p-value, and Cohen's d for one-sample, two-sample (Welch's), and paired t-tests. Includes critical value table and distribution visual.
Two Envelopes Paradox Simulator
Simulate the two envelopes paradox with Monte Carlo trials. Compare switch vs keep strategies, visualize convergence, and understand the probability fallacy.
Upper & Lower Fence Calculator
Calculate both inner and outer fences for outlier detection. Shows box plot with dual fence boundaries, five-number summary, data classification, and distribution shape analysis.
Upper Control Limit (UCL) Calculator
Calculate UCL, LCL, and center line for X-bar, R, S, p, np, c, and u control charts. Includes interactive control chart, SPC constants, and out-of-control detection.
Upper Fence Calculator
Calculate upper fence for outlier detection using the IQR method. Shows box plot, fence comparison at multiple k-values, and classifies every data point as normal, mild, or extreme outlier.
Youden's Index Calculator
Calculate Youden's J statistic from sensitivity and specificity or a 2×2 table. Includes ROC space visualization, PPV/NPV, DOR, LR+/LR−, MCC, and a 13-metric performance dashboard.