Statistics Calculators

Calculate mean, median, and mode of any dataset. Enter values — see all three averages, sorted data, frequency table, and range. Free.

Calculate variance and standard deviation. Step-by-step solution with formula, example dataset and interpretation guide.

Calculate confidence intervals for population means. Step-by-step solution with formula, example dataset and interpretation guide.

Convert correct answers to percentage and letter grade. Fast and accurate result with formula, step-by-step method and unit overview. Free tool.

Find the arithmetic mean of any set of numbers. Enter your values — see the mean, sum, count, and how each value affects the average. Free.

Calculate quartiles and IQR. Step-by-step solution with formula, example dataset and interpretation guide.

Find percentile rank of data values. Step-by-step solution with formula, example dataset and interpretation guide.

Calculate statistical variance. Step-by-step solution with formula, example dataset and interpretation guide.

Calculate z-score from any value, mean, and standard deviation. Enter your data — see z-score, percentile rank, and probability under the normal curve. Free.

Complete statistical summary of any dataset. Enter your values — see mean, median, mode, variance, standard deviation, and percentiles. Free.

Add a list of numbers quickly and accurately. Enter your values separated by commas — see the sum, average, count, min, and max. Free.

Generate random numbers in any range with or without repetition. Enter min, max, and count — see your random numbers instantly. Free.

Pick random names from your list with equal probability. Enter names one per line — select one or multiple and get fair random results. Free.

Flip a fair coin and track results over multiple flips. Choose flip count — see heads/tails results with running probability statistics. Free.

Calculate Grade quickly and accurately. Enter your values — see the result with the formula, worked example, and unit options. Free.

Calculate GPA quickly and accurately. Enter your values — see the result with the formula, worked example, and unit options. Free.

Calculate Vote Percentage quickly and accurately. Enter your values — see the result with the formula, worked example, and unit options. Free.

Generate stem-and-leaf plots from any dataset. Enter your values — see the completed plot with back-to-back option and median marked. Free.

Calculate required sample size for surveys and experiments. Enter confidence level, margin of error, and population — get the minimum n. Free.

Calculate margin of error for survey results. Enter sample size, confidence level, and proportion — get the margin of error and confidence interval. Free.

Run a chi-square goodness of fit or independence test. Enter observed and expected frequencies — see χ², p-value, and interpretation. Free.

Run a two-sample independent t-test. Enter your data sets — see the t-statistic, degrees of freedom, p-value, and statistical conclusion. Free.

Calculate Pearson or Spearman correlation coefficient. Enter paired data — see r value, r², and scatter plot interpretation. Free.

Calculate Spearman rank correlation between two variables. Enter paired data — see ρ, p-value, and monotonic relationship strength. Free.

Coefficient of determination R². Formula, variable legend, diagram and worked example included. Instant geometry result.

Calculate Cohen's d effect size for comparing two group means. Enter means and standard deviations — see d with small/medium/large benchmarks. Free.

Calculate probabilities for any normal distribution. Enter mean, standard deviation, and x value — get P(X<x), P(X>x), and z-score. Free.

Calculate binomial distribution probabilities. Enter n, k, and p — see P(X=k), cumulative P(X≤k), mean, variance, and probability chart. Free.

Calculate Poisson probabilities for rare events. Enter λ (average rate) and k — see P(X=k), cumulative probability, and expected value. Free.

Calculate the geometric mean of any dataset. Enter values — see the nth root formula, result, log method, and comparison with arithmetic mean. Free.

Calculate the harmonic mean of any set of values. Enter your numbers — see n ÷ Σ(1/xᵢ) with result and comparison to arithmetic mean. Free.

Calculate weighted mean with custom weights for each value. Enter values and weights — see the weighted average with each contribution shown. Free.

Calculate IQR quickly and accurately. Enter your values — see the result with the formula, worked example, and unit options. Free.

Calculate the regression slope and linear equation from two variables. Enter your data — see slope, intercept, correlation coefficient, and residuals. Free.

Calculate statistical power for any study design. Enter effect size, sample size, and significance level — see power and minimum sample needed. Free.

Calculate the trimmed (truncated) mean by removing extreme values. Enter your dataset and trim percentage — see the robust average. Free.

Calculate probability for any event or distribution. Enter your parameters — see probability, odds, and expected value. Free.

Internal consistency reliability. Full formula with variable legend, worked example and step-by-step chemistry solution.

Analysis of variance across multiple groups. Step-by-step solution with formula, example dataset and interpretation guide.

Run a Mann-Whitney U test for non-parametric group comparison. Enter two datasets — see U statistic, p-value, and statistical conclusion. Free.

Compare the variances of two groups with an F-test. Enter both datasets — see the F statistic, p-value, and whether variances are equal. Free.

Understand Type I and Type II errors, alpha, beta, and statistical power. Enter your α, effect size, and n — see power and error probabilities. Free.

Determinant, inverse, addition and multiplication of 2×2 matrices. See formula, step-by-step solution and all rearrangements. Instant math solver.

Solve proportions and find missing values. Enter three of four values in a/b = c/d — see the missing value with cross-multiplication steps. Free.

Perform union, intersection, difference, and symmetric difference of sets. Enter set members — see the result with Venn diagram representation. Free.

Check divisibility by 2 through 12 with instant rule explanations. Enter any integer — see which numbers divide it evenly and the rule used. Free.

Calculate square root, cube root, or any nth root. Enter value and root index — see the exact result, decimal approximation, and verification. Free.

Detect outliers in any dataset using the IQR method. Enter your values — see Q1, Q3, IQR, whisker bounds, and identified outliers. Free.