Free Standard Deviation Calculator to calculate sample and population SD, variance, and mean with fast and accurate results.
Standard deviation measures the amount of variation in a set of values.
Sample Standard Deviation: s = √[Σ(x - x̄)² / (n - 1)]
Population Standard Deviation: σ = √[Σ(x - x̄)² / n]
Where: x̄ = mean, x = each value, n = number of values
Population standard deviation is used when you have data for an entire population, while sample standard deviation is used for a subset of data representing a larger population.
You need at least two data points to calculate standard deviation, but more data points provide more accurate results.
A high standard deviation indicates that data points are spread out over a wider range of values, showing more variability in your data set.
Yes, the calculator accepts decimal numbers and provides precise calculations for any numerical data set.