Statistics Calculator
Mean, median, mode, standard deviation and more for any list of numbers.
Overview
The Statistics Calculator summarises any list of numbers with the headline measures: mean, median, mode, range, variance, standard deviation, quartiles, minimum, maximum and count. Paste a column, separate values with commas or spaces, and read the descriptive statistics at a glance.
It is useful for students working through data-analysis homework, analysts checking a quick column of values, scientists pre-screening a dataset and anyone needing more than what a single mean tells you.
How it works
The mean is Σ x / n. The median is the middle value once sorted (or the average of the two middle values for an even count). Mode is the most frequent value, with ties reported as a multimodal set.
Sample variance is Σ (x - mean)² / (n - 1). Standard deviation is the square root of variance. Quartiles split the sorted data into four parts; Q1 and Q3 use linear interpolation between adjacent order statistics. Range is max - min.
Examples
[2, 4, 4, 4, 5, 5, 7, 9]
→ mean 5, median 4.5, mode 4, sd ≈ 2.14
[10, 20, 30, 40, 50]
→ mean 30, median 30, Q1 = 20, Q3 = 40, sd ≈ 15.81
[1, 1, 2, 2, 3, 3]
→ multimodal: 1, 2, 3 each appear twice
[5] → mean 5, sd undefined (need n ≥ 2)
FAQ
Sample or population variance?
The calculator returns sample variance by default (divides by n - 1). Population variance divides by n and is appropriate when the data are the entire population.
Why is mode sometimes a list?
When multiple values tie for the highest count, every tying value is reported. If all values are unique, there is no mode.
How are quartiles computed?
Using linear interpolation between adjacent order statistics (Type 7, the R default). Different conventions exist; results may differ slightly from textbook examples.
What if my data have outliers?
Mean and standard deviation get pulled by outliers; median and quartiles are robust. Use both views to spot skewed data.
Can I get a histogram?
This tool returns scalar summaries. For visualisations, look at dedicated charting tools.