📊 Statistics calculators

Mean, standard deviation, probability, tests. 20 calculators.

• Binomial Probability CalculatorCalculate the probability of exactly k successes in n independent trials with success probability p.
• Coefficient of Variation CalculatorCalculate the coefficient of variation (relative standard deviation) of a data set to compare variability.
• Combination Calculator (nCr)Calculate the number of combinations — ways to choose r items from n when order doesn't matter. Lottery odds included.
• Confidence Interval Calculator (Mean)Calculate a confidence interval for a mean from the sample mean, standard deviation and sample size.
• Empirical Rule Calculator (68–95–99.7)Find the ranges containing 68%, 95% and 99.7% of values in a normal distribution from the mean and standard deviation.
• Geometric Mean CalculatorCalculate the geometric mean of positive numbers — the correct average for growth rates, ratios and returns.
• Margin of Error CalculatorCalculate the margin of error for a survey or poll from sample size, proportion and confidence level.
• Mean, Median & Mode CalculatorFind the mean, median, mode and range of any list of numbers — paste data from a spreadsheet.
• Normal Distribution Probability CalculatorFind the probability that a normally distributed value is below, above or between limits — from mean and standard deviation.
• Odds to Probability ConverterConvert betting or statistical odds to probability and back — fractional odds, decimal odds and percentage chance.
• Permutation Calculator (nPr)Calculate the number of permutations — ordered arrangements of r items chosen from n.
• Poisson Probability CalculatorCalculate the probability of exactly k events in an interval when events occur at an average rate λ.
• Probability Calculator (Two Events)Calculate the probability of A and B, A or B, not A, and neither — for two independent events.
• Quartile & IQR Calculator (Five-Number Summary)Calculate quartiles Q1, Q2, Q3, the interquartile range and outlier fences — the five-number summary for a box plot.
• Relative Risk & Odds Ratio CalculatorCalculate relative risk, odds ratio and absolute risk difference from a 2×2 table of exposed and unexposed groups.
• Sample Size Calculator (Surveys)Find how many survey responses you need for a given margin of error and confidence level — with finite population correction.
• Standard Deviation CalculatorPaste your data to get sample and population standard deviation, variance, mean and count — with steps.
• Standard Error of the Mean CalculatorCalculate the standard error of the mean (SEM) from your data — or from standard deviation and sample size.
• Sum of Squares CalculatorCalculate the total sum of squares (squared deviations from the mean) and the sum of squared values for a data set.
• Z-Score CalculatorCalculate the z-score of a value from the mean and standard deviation — plus its percentile under a normal distribution.