Standard Deviation Calculator
Calculate Standard Deviation
Results
Enter values and click calculate to see results
Understanding Standard Deviation
What is Standard Deviation?
- Measures spread of data from mean
- Lower values = data close to mean
- Higher values = data more spread out
- Uses same units as original data
When to Use Each Type
- Population (σ): Complete dataset
- Sample (s): Subset of population
- Sample uses n-1 (Bessel's correction)
- Most real-world data uses sample
Interpreting Results
- ±1σ contains ~68% of data
- ±2σ contains ~95% of data
- ±3σ contains ~99.7% of data
- Compare to mean for context