45 FREE TOOLS · σ
Statistics calculators
Summaries, probabilities and common data relationships.
Descriptive statistics
Summarise location, dispersion and standardised differences.
Explore topic ↗10 calculatorsProbability & distributions
Explore event counts, conditional probabilities and simple distribution models.
Explore topic ↗6 calculatorsSampling uncertainty
Explore standard errors, normal-model margins and planning sample sizes.
Explore topic ↗5 calculatorsRegression & paired data
Explore covariance, correlation and fitted straight-line relationships.
Explore topic ↗All statistics calculators
Arithmetic Mean Calculator
Find the arithmetic mean of a variable-length list of numbers.
Weighted Mean Calculator
Combine three values using non-negative weights.
Median Calculator
Find the median of a variable-length numeric dataset.
Data Range Calculator
Find the difference between the largest and smallest values in a dataset.
Population Standard Deviation Calculator
Find population standard deviation from a list of numeric observations.
Sample Standard Deviation Calculator
Estimate sample standard deviation from a variable-length numeric list.
Z Score Calculator
Express a value’s distance from the mean in standard deviations.
Standard Error Calculator
Estimate the standard error of a sample mean.
Independent Events Probability Calculator
Find the probability that two independent events both occur.
At Least One Event Calculator
Calculate the probability of at least one success in independent identical trials.
Coefficient of Variation Calculator
Express a standard deviation relative to a positive mean.
Relative Error Calculator
Compare absolute measurement error with a positive reference value.
Binomial Probability Calculator
Find the probability of exactly k successes in n independent identical trials.
Poisson Probability Calculator
Find the probability of a specific event count under a Poisson model.
Binomial Mean Calculator
Find the expected number of successes across identical independent trials.
Binomial Standard Deviation Calculator
Find the standard deviation of the success count in a binomial model.
Expected Monetary Value Calculator
Combine two mutually exclusive outcomes using a chosen probability.
Bayes Theorem Calculator
Update a prior probability using likelihoods for evidence under two alternatives.
Proportion Standard Error Calculator
Estimate the standard error of a sample proportion under a simple independent-sampling model.
Normal Confidence Interval Margin Calculator
Calculate the margin around a mean from a supplied z critical value.
Sample Size for a Proportion Calculator
Estimate a normal-approximation sample size for a target proportion margin.
Root Mean Square Calculator
Calculate RMS for four equally weighted observations.
Geometric Mean Calculator
Find the geometric mean of three positive values.
Harmonic Mean Calculator
Find the harmonic mean of two positive values.
Pooled Standard Deviation Calculator
Combine two sample deviations under a common-variance assumption.
Cohens D Calculator
Calculate a mean difference standardised by a supplied pooled deviation.
Uniform Distribution Probability Calculator
Find probability over an interval within a continuous uniform distribution.
Exponential Survival Probability Calculator
Find the probability of waiting longer than a chosen time in an exponential model.
Statistics Calculator
Summarise a numeric dataset with its count, mean, median, minimum and maximum.
Mode Calculator
Find the most frequent value or tied values in a numeric dataset.
Percentile Calculator
Find a dataset percentile using inclusive linear interpolation.
Interquartile Range Calculator
Measure the spread of the middle half of a dataset.
Percentile Rank Calculator
Find the percentage of supplied observations strictly below a chosen value.
Population Variance Calculator
Find population variance for a variable-length numeric dataset.
Sample Variance Calculator
Estimate variance using N minus one for a supplied sample.
Pearson Correlation Calculator
Measure linear association between two equal-length numeric datasets.
Linear Regression Slope Calculator
Find the ordinary-least-squares slope for Y on X.
Linear Regression Intercept Calculator
Find the intercept of an ordinary-least-squares Y-on-X line.
Linear Regression Prediction Calculator
Predict a Y value from a fitted unweighted line and a chosen X value.
Covariance Calculator
Calculate sample covariance of two paired datasets.
Mean Absolute Deviation Calculator
Find mean absolute distance from the arithmetic mean.
Median Absolute Deviation Calculator
Find the median absolute distance from the dataset median.
Trimmed Mean Calculator
Average a dataset after trimming equal whole-number counts from both tails.
Z Test P Value Calculator
Find an approximate normal-model p-value from a supplied z statistic and a chosen tail.
Normal Mean Confidence Interval Calculator
Find a symmetric normal-model interval from a mean, known population deviation and chosen critical value.
Make your inputs count
Define the population, sample and observation units before calculating. A descriptive statistic summarises the numbers entered; it does not establish a cause or validate a sampling method. Probability models require the independence and distribution assumptions stated.