Standard Deviation Calculator
Calculate population and sample standard deviation, variance, mean, median, min, max, and range for a list of comma or space-separated values. Free and instant.
Data Dataset
Statistical metrics
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How to Use Standard Deviation Calculator
Standard Deviation Calculator Formula / How It Works
This calculator splits input text into individual numbers. It computes the arithmetic mean, then calculates the squared deviation of each number from that mean. It sums these squared values and divides by N (for population) or N-1 (for sample), finally taking the square root.
For example, for the dataset [2, 4, 4, 4, 5, 5, 7, 9], the Mean is 5.00, the Population SD is 2.00, and the Sample SD is 2.1381.
Frequently Asked Questions
Population SD (σ) is used when you have the complete dataset of the entire population. Sample SD (s) is used when your data represents a sample selected from a larger population, applying Bessel's correction (N - 1) to account for bias.
Variance is the average of the squared differences from the mean. Standard deviation is simply the square root of the variance.
This tool is highly flexible and accepts numbers separated by commas, spaces, tabs, or newlines.
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