Calculators

Estimates the minimum sample size required to achieve a desired level of confidence and margin of error for a study.

Illustrates how the sampling distribution of the mean approaches normality as sample size increases.

Calculates the original data point value given a Z-score, mean, and standard deviation.

Calculates Defects Per Million Opportunities (DPMO), a quality metric representing the number of defects per million opportunities in a process.

Calculates the proportion of the variance in the dependent variable that is predictable from the independent variable(s) in a regression.

Calculates a single value used to estimate a population parameter, such as the sample mean estimating the population mean.

Calculates the median of a set of numbers. The median is the middle value in a dataset when the numbers are arranged in order.

Calculates the difference between the maximum and minimum values in a dataset.

Calculates the statistical significance and other key metrics for A/B test results.

Calculates the entropy (average level of information, surprise, or uncertainty) inherent in a variable's possible outcomes.