Statistics Calculator

Compute comprehensive descriptive statistics for any data set

About the Statistics Calculator

This statistics calculator computes a complete set of descriptive statistics for any numerical data set. It calculates central tendency measures (mean, median, mode), dispersion measures (range, variance, standard deviation), and positional measures (quartiles, IQR). Both sample and population formulas are provided where applicable.

Key Formulas

Sample Variance: s² = Σ(xᵢ − x̄)² / (n − 1)
Population Variance: σ² = Σ(xᵢ − μ)² / N

Frequently Asked Questions

When should I use sample vs. population standard deviation?

Use the population formula when your data includes every member of the entire group. Use the sample formula (with n-1 in the denominator, known as Bessel's correction) when your data is a sample from a larger population, as it provides an unbiased estimate of the population parameter.

What is the interquartile range (IQR) used for?

The IQR (Q3-Q1) measures the spread of the middle 50% of the data. It is less sensitive to outliers than the range and is used in box plots to identify outliers. Any data point more than 1.5 × IQR below Q1 or above Q3 is typically considered an outlier.