Statistics Calculator
Enter a list of numbers and get full descriptive statistics instantly.
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Frequently Asked Questions
Population std dev (σ) divides by N — use when your data is the entire population. Sample std dev (s) divides by N-1 (Bessel's correction) — use when your data is a sample from a larger population. The sample version gives an unbiased estimate of the true population standard deviation.
Use the median when your data has outliers or is skewed. For example, household income data is typically reported as median because a few very high earners would inflate the mean and misrepresent the "typical" income.
The Interquartile Range (IQR) is Q3 − Q1. It represents the spread of the middle 50% of the data. Values more than 1.5×IQR below Q1 or above Q3 are typically considered outliers.