Statistics Calculator
Paste a dataset and get the full descriptive summary — centre, spread, shape, and outliers — with an inline histogram of the distribution.
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What every statistic measures
- Mean. The arithmetic average. Sensitive to outliers.
- Median. The middle value once sorted. Robust to outliers, which is why it is preferred for skewed data.
- Mode. The most frequent value. A dataset can have no mode, one mode, or be multimodal.
- Range. Maximum minus minimum. Crude but quick.
- Variance and standard deviation. Both measure spread; standard deviation is in the same units as the data. The calculator reports both the population and sample versions.
- Quartiles and IQR. Q1 cuts off the bottom 25% of the data, Q3 cuts off the top 25%, and the IQR is Q3 − Q1. Anything more than 1.5 × IQR away from those quartiles is conventionally an outlier.
- Skewness. Negative means a long left tail, positive means a long right tail, zero is symmetric.
- Kurtosis (excess). Compares the tails of your distribution to a normal distribution. Positive means heavier tails (more outliers), negative means lighter tails.
Sample vs population
The sample variance divides by n − 1, the population variance divides by n. Use the sample version (Bessel’s correction) when your data is a representative sample of a larger group; use the population version when your data is the entire group.