Statistics & Analysis
Statistical calculators developed by data scientists and statisticians. Our analysis tools provide accurate computations for probability, distributions, hypothesis testing, and data analysis, essential for researchers, analysts, and students.
Statistics & Analysis
A/B Test Significance Calculator
Calculates A/B test statistical significance from visitor and conversion counts. Returns the p-value, z-score, confidence interval, and uplift for two variants.
Altman Z-Score Calculator: Bankruptcy Risk Formula
The Altman Z-Score calculator estimates a company's bankruptcy risk over two years, using Altman's five-ratio formula applied to its financial statements.
Binomial Distribution Calculator - Free Probability Tool
Calculate binomial distribution probabilities instantly. Free online calculator for statistics, data science, and probability theory with step-by-step results.
Box Plot Calculator: Quartiles, Median and Outliers
Calculate the five-number summary of a data set (minimum, Q1, median, Q3, maximum), find outliers with the 1.5 IQR rule, and view it as a box-and-whisker plot.
Confidence Interval to Standard Deviation Calculator
Convert a confidence interval percentage into a z-score, the number of standard deviations from the mean of a normal distribution, with formula and example.
Critical Value Calculator | Z-test, t-test, Chi-Square
Find one-tailed and two-tailed critical values for Z-tests, t-tests, and Chi-squared tests. Enter alpha and degrees of freedom for instant, accurate results.
Fisher's Exact Test Calculator - Free Statistical Tool
Calculate exact p-values for 2×2 contingency tables with Fisher's exact test. Perfect for small sample sizes when chi-square assumptions fail. Free online tool.
Gamma Distribution Calculator - Statistical Analysis Tool
Find the mean, variance, skewness, kurtosis, and mode of a gamma distribution from its shape and scale parameters, plus a probability density chart and formula.
Gender Pay Gap Calculator - Salary Disparity & Percentage
Free gender pay gap calculator instantly compares two salaries. Calculate dollar difference and percentage disparity for pay equity audits and negotiations.
Laplace Distribution Calculator - Peak Density & Graph
Compute the peak probability density of a Laplace distribution from its location and scale parameters, and view the density curve on an interactive graph.
Poisson Distribution Calculator | Probability Tool
Calculate Poisson distribution probabilities from a rate (lambda) and event count (k). Free online tool with formula, worked examples, and a probability chart.
Raw Score Calculator - Convert Z-Score to Original Value
Convert a z-score to a raw score using the mean and standard deviation. Free calculator with formula, worked examples, and a normal distribution chart.
Six Sigma Calculator: DPMO, Yield & Sigma Level
Calculate DPMO, process yield, and sigma level from a defect count, opportunities per unit, and total units produced with this free Six Sigma calculator.
Standard Deviation Index Calculator | Free SDI Tool
Free calculator for the Standard Deviation Index (SDI), used in lab quality control. Enter a test result, control mean, and standard deviation to find SDI.
T-Test Calculator - Free Online Statistical Analysis Tool
Free t-test calculator. Enter sample data to get the t-statistic, degrees of freedom, and p-value for one-sample, two-sample, and paired t-tests instantly.
Z-Score Calculator - Standard Score & Probability Tool
A z-score calculator finds how many standard deviations a data point is from the mean, using z = (x - mean) / standard deviation, plus cumulative probability.
Z-Test Calculator: Formula, Steps and Worked Example
Calculate a one-sample z-test online. Enter the sample mean, population mean, standard deviation, and sample size to get the z-score and a worked example.