Standard Deviation Calculator
Calculate descriptive statistics with data visualization
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Standard Deviation Information
Standard Deviation
Measures the spread of data points from the mean. Lower values indicate data points are closer to the mean.
Sample vs Population
Sample uses n-1 (Bessel's correction), Population uses n. Choose based on whether your data represents the entire population.
68-95-99.7 Rule
In normal distributions: ~68% within 1σ, ~95% within 2σ, ~99.7% within 3σ of the mean.
Variance
The square of standard deviation. Useful for mathematical calculations but less intuitive than standard deviation.