Standard Deviation Calculator
Calculate population and sample standard deviation, variance, and mean.
Google ad
Google ad
Google ad
Popular Calculators
- Age Calculator
- Molarity Calculator
- Dilution Calculator (C₁V₁ = C₂V₂)
- GCD & LCM Calculator
- Time Converter
- Area & Perimeter Calculator
- Temperature Converter
- Work Days Calculator
- Kinetic Energy Calculator
- Calories Burned Calculator
- Body Fat Percentage Calculator
- Discount Calculator
- Daily Protein Intake Calculator
- pH Calculator
- Charles's Law Calculator
FAQs
When do I use population vs sample standard deviation?
Use population standard deviation (σ) when you have data for the entire group. Use sample standard deviation (s) when your data is a sample drawn from a larger population — this is the more common case in research.
What does the 68-95-99.7 rule mean?
In a normal distribution, approximately 68% of values fall within 1 standard deviation of the mean, 95% within 2, and 99.7% within 3. This rule is used extensively in quality control and scientific research.
What is the difference between variance and standard deviation?
Variance is the average of the squared differences from the mean. Standard deviation is the square root of variance, putting it back in the same units as the original data and making it easier to interpret.