Statistics Calculators
30 free calculators for statistics questions, planning, estimates and everyday decisions.
Mean Calculator
Calculate the arithmetic mean, count, sum, minimum, and maximum of a dataset.
Median Calculator
Find the median and middle position of an ordered dataset.
Mode Calculator
Find the most frequently occurring value or values in a dataset.
Range Calculator
Calculate the range, minimum, maximum, and midrange of a dataset.
Variance Calculator
Calculate population and sample variance from a dataset.
Standard Deviation Calculator
Calculate population and sample standard deviation from a dataset.
Standard Error Calculator
Calculate the standard error of the mean from sample standard deviation and sample size.
Z-Score Calculator
Calculate how many standard deviations a value lies above or below the mean.
Percentile Calculator
Estimate a percentile value from an ordered dataset using linear interpolation.
Quartile Calculator
Calculate the first quartile, median, and third quartile of a dataset.
Interquartile Range Calculator
Calculate Q1, Q3, the interquartile range, and common outlier fences.
Correlation Coefficient Calculator
Calculate Pearson's correlation coefficient for paired x and y values.
Linear Regression Calculator
Fit a least-squares line to paired x and y data.
Confidence Interval Calculator
Calculate a normal-approximation confidence interval for a population mean.
Sample Size Calculator
Estimate a sample size for a population proportion using confidence level and margin of error.
Chi-Square Calculator
Calculate a chi-square goodness-of-fit statistic from observed and expected counts.
t-Test Calculator
Calculate a two-sample Welch t statistic from summary statistics.
Normal Distribution Calculator
Estimate the cumulative probability below a value in a normal distribution.
Binomial Distribution Calculator
Calculate the probability of exactly k successes in n independent trials.
Probability Distribution Calculator
Calculate the expected value and variance of a discrete probability distribution.
Four Value Mean Calculator
Calculate the mean of four values.
Four Value Range Calculator
Calculate the range of four values.
Population Variance Calculator
Calculate population variance for four values.
Population Standard Deviation Calculator
Calculate population standard deviation for four values.
Standard Score Z Calculator
Calculate a z-score from value, mean, and standard deviation.
Relative Risk Calculator
Calculate relative risk from two event rates.
Odds Calculator
Convert probability percentage to odds.
Margin of Error Calculator
Estimate a 95% margin of error for a proportion.
Sample Size Proportion Calculator
Estimate sample size for a proportion at 95% confidence.
Percentile Rank Calculator
Calculate percentile rank from values below and total observations.