GIGAcalculator

Choose the tool, then use its question-mark help and method notes to match the inputs to the model. GIGAcalculator's standard-deviation worksheet separates continuous raw data from binomial rates, which use a sample size and event proportion. A Sample/Population switch selects the applicable calculation; outputs include deviation, variance, mean, range, count and standard error. Standard deviation has the same units as the data, whereas the guide defines variance through squared deviations. Its sample-estimation discussion warns about bias with fewer than ten observations. Share, embed and citation controls are present. The collection is free, with each model's assumptions documented on its own page.