statistics Calculators
Mean Calculator
Quickly find the arithmetic mean (average) of any list of numbers. Enter your comma-separated dataset and get the result instantly — ideal for students, analysts, and researchers summarizing data.
Standard Deviation Calculator
Compute the sample standard deviation directly from three summary statistics — sample size n, the sum of values Σx, and the sum of squared values Σx². This is the spread metric used in virtually every empirical study, quality-control chart, and risk model.
Correlation Coefficient Calculator
Compute the Pearson correlation coefficient (r) between two variables from paired summary statistics — n, Σxy, Σx, Σy — to measure how strongly they move together linearly. The number ranges from −1 (perfect negative linear relationship) through 0 (no linear relationship) to +1 (perfect positive linear relationship).
Z-Score Calculator
Convert any raw value into a z-score — the number of standard deviations it sits above or below the mean of its distribution. Used everywhere from standardised test reporting and quality control to risk modelling and machine-learning feature scaling.
Sample Size Calculator
Calculate the minimum number of respondents needed to estimate a population proportion within a given margin of error at a chosen confidence level — the standard formula behind almost every survey, poll, and quality audit. Includes the finite-population correction so you can plan surveys of small populations without over-sampling.
Confidence Interval Calculator
Compute the lower and upper bounds of a confidence interval for a population mean using a sample mean, the standard error of that mean, and a critical z-value (1.645 / 1.96 / 2.576 for 90% / 95% / 99% confidence). This is the standard way to report uncertainty around survey results, lab measurements, or any sample-based estimate.
Variance Calculator
Compute population or sample variance from the sum of squared deviations and number of values. Useful in statistics coursework, quality control, and any analysis that requires measuring data spread.
Linear Regression Slope Calculator
Calculate the slope of a least-squares linear regression line from summary statistics of your dataset. Use this in data analysis, forecasting, and whenever you need to quantify how much y changes per unit increase in x.
Chi-Square Test Calculator
Compute the chi-square test statistic to determine if observed frequencies differ significantly from expected ones. Commonly used in genetics, market research, and any test of independence or goodness of fit.
Coefficient of Variation Calculator
Calculate the coefficient of variation (CV) to compare variability across datasets with different units or means. Ideal for comparing measurement precision, investment risk, or biological variability between groups.
One-Sample T-Test Calculator
Test whether your sample mean differs significantly from a known population mean. Use this when evaluating survey results, quality control data, or any study where you have one group and a benchmark to compare against.
One-Way ANOVA Calculator
Determine whether the means of three or more groups differ significantly using the F-statistic. Ideal for experiments comparing multiple treatments, teaching methods, or product variants in a single analysis.
Standard Error Calculator
Calculate the standard error of the mean to quantify how precisely your sample mean estimates the true population mean. Use it when building confidence intervals or evaluating the reliability of survey or experimental data.
Linear Regression Calculator
Find the best-fit straight line through your data by calculating the slope and intercept of a linear regression model. Use it to predict outcomes, quantify relationships, and assess how well X explains Y.
Normal Distribution Probability Calculator
Calculate the probability that a normally distributed random variable falls within a specified range, below a threshold, or above one — using the mean and standard deviation that fully describe the bell curve. Used for Six Sigma quality control, finance (VaR), psychometrics, and any process modelled by the normal distribution.
Confidence Interval Calculator
Estimate the range where a population mean likely falls using your sample data. Use this when reporting survey results, lab measurements, or any study where you need to quantify uncertainty around an estimate.
Hypothesis Test Calculator
Compute a z-score or t-statistic to determine whether your sample mean differs significantly from a hypothesized population mean. Use it for quality control checks, clinical trials, and any experiment where you need to accept or reject a null hypothesis.
Linear Regression Calculator
Find the linear relationship between two variables by computing the slope, correlation coefficient, and R² from paired data points. Use it when analyzing trends in sales, scientific experiments, or any dataset where you want to predict one variable from another.
Chi-Square Test Calculator
Compute the chi-square statistic to test whether observed frequencies differ significantly from expected ones, or whether two categorical variables are independent. Use it for analyzing survey responses, genetic ratios, market research, and contingency tables.
Standard Error Calculator
Calculate the standard error of the mean to measure how precisely your sample mean estimates the true population mean. Use it in research reports, quality control, and any analysis where you need to quantify sampling variability.
Statistical Power Calculator
Determine the statistical power of a hypothesis test given effect size, sample size, and alpha level. Use it when designing experiments to confirm you have enough participants to detect a real effect.
Descriptive Statistics Calculator
Compute key summary statistics — mean, median, variance, and standard deviation — from any list of numbers. Ideal for quickly summarizing datasets in research, class assignments, or data analysis.
Correlation Coefficient Calculator
Compute the Pearson correlation coefficient r and coefficient of determination R² from summary statistics of paired data. Use it to measure the linear relationship between two variables in research or data analysis.
ANOVA F-Test Calculator
Compute the F-statistic for a one-way ANOVA test by entering sums of squares and degrees of freedom. Use it when comparing means across three or more groups to test whether at least one differs significantly.
Chi-Square Test Calculator
Compute the chi-square (χ²) statistic from observed and expected frequencies to test goodness of fit or independence. Use it whenever you need to determine whether categorical data match a theoretical distribution.
Binomial Probability Calculator
Compute the exact probability of getting exactly k successes in n independent trials, each with probability p. Use this when modeling coin flips, quality control tests, or any repeated yes/no experiment.
Standard Deviation Calculator
Instantly find the standard deviation and variance of any numeric data set, choosing between population or sample formulas. Ideal for students, researchers, and analysts summarizing data spread.
Normal Distribution Calculator
Find the cumulative probability P(X ≤ x) for a normal distribution given any mean, standard deviation, and x value. Useful for statistics students, researchers, and engineers working with continuous random variables.
Normal Distribution Calculator
Convert any raw value to a z-score using a custom mean and standard deviation, then find corresponding normal distribution probabilities. Perfect for standardizing test scores, measurements, or survey results.
P-Value Calculator
Convert a z-score (or any standard-normal test statistic) into a p-value for a one- or two-tailed hypothesis test, then see it visualised as the shaded tail area on the standard normal curve. The smaller the p-value, the stronger the evidence against the null hypothesis — reject H₀ when p drops below your significance threshold (commonly 0.05).
Mean, Median, Mode Calculator
Find any of the three classic measures of central tendency — mean, median, or mode — from a comma-separated list of numbers. Use the mean for symmetric data, the median for skewed data, and the mode for the most common value.
Linear Regression Calculator
Fit a least-squares regression line y = a + b·x to paired x and y values and read off the slope, intercept, or coefficient of determination (r²). Used in forecasting, trend analysis, and any setting where you want to quantify how much y changes with x.