Standard Deviation Calculator - Calculate Variance and Statistical Measures
Standard deviation is one of the most important measures in statistics, quantifying the amount of variation or dispersion in a set of data values. A low standard deviation indicates that values tend to be close to the mean, while a high standard deviation indicates that values are spread out over a wide range.
Our free standard deviation calculator computes both population and sample standard deviation, along with variance, mean, median, range, and other descriptive statistics. Simply enter your numbers separated by commas or one per line, and the calculator instantly provides a comprehensive statistical summary.
Understanding the difference between population and sample standard deviation is crucial. Population standard deviation divides the sum of squared differences by N (the total count), while sample standard deviation divides by N-1 to correct for bias when estimating from a subset of data. Use population mode when you have the complete dataset, and sample mode when working with a subset.
This tool is perfect for students studying statistics, researchers analyzing data, quality control professionals monitoring manufacturing processes, and anyone who needs quick statistical calculations without installing specialized software. All calculations happen in your browser for instant results and complete data privacy.