Variance Calculator
Calculate variance and standard deviation to measure data spread and variability.
Enter Numbers
Results
Sample Variance (s²)
27.4286
Most commonly used
Population Variance (σ²)
24.0000
Sample Std Dev (s)
5.2372
Population Std Dev (σ)
4.8990
Mean (μ)
18.0000
Count (n)
8
What is Variance?
Variance measures how far a set of numbers are spread out from their average value. Higher variance means data points are more spread out; lower variance means they're closer to the mean.
Sample vs Population Variance
- Sample Variance (s²): Use when analyzing a sample. Divides by (n-1) for unbiased estimate.
- Population Variance (σ²): Use for entire population. Divides by n.
Variance vs Standard Deviation
- Variance: Average of squared differences (units²)
- Standard Deviation: Square root of variance (same units as data)
When to Use
- Measuring investment risk and volatility
- Quality control and manufacturing consistency
- Comparing variability between datasets
- Statistical hypothesis testing