Standard Deviation Calculator
Calculate standard deviation, variance, and confidence intervals for your data
Calculate standard deviation, variance, mean, and other statistics for your dataset.
About Standard Deviation
Formulas
Population: σ = √(Σ(x-μ)²/N)
Sample: s = √(Σ(x-x̄)²/(n-1))
Key Terms:
- • Mean (μ): Average of all values
- • Variance (σ²): Average squared deviation
- • Std Dev (σ): Square root of variance
- • Std Error: σ / √N
When to Use:
- • Population: When data includes entire group
- • Sample: When data is a subset