Descriptive statistics
Mean, median, mode, variance, standard deviation, quartiles, min and max for a list of numbers. Runs in your browser, no upload.
About this tool
Descriptive statistics summarises a list of numbers with the measures you'd reach for in a stats class or a quick data check:
- Centre: mean, median, mode (the most frequent value(s) — or none if all are unique)
- Spread: variance and standard deviation — both population (÷N) and sample (÷N−1) — plus range and the interquartile range (IQR)
- Position: min, max, first quartile (Q1) and third quartile (Q3)
- Totals: count and sum
Enter the numbers separated by spaces, commas, semicolons, or newlines. Quartiles use the common linear-interpolation method (the numpy default).
Privacy
Everything runs in your browser via WebAssembly — your data is never uploaded. Also available from the gizza CLI and in chat (which return the values as structured JSON).
FAQ
Why do I get two different standard deviations?
The tool reports both conventions: population standard deviation divides by N (use it when your numbers are the whole population) and sample standard deviation divides by N−1 (use it when they're a sample of something larger). With fewer than 2 numbers the sample figures are undefined and shown as blank.
My quartiles don't match Excel — which method is used?
Q1, the median and Q3 use linear interpolation on the sorted data — the
same method as numpy's default percentile. Excel's QUARTILE.INC matches
it, but QUARTILE.EXC and some textbooks use different conventions, so small
differences on short lists are expected and not a bug.
What does "mode: none" mean, and can there be several modes?
If no value appears more than once there is no mode, so the tool says none rather than picking one arbitrarily. When several values tie for the highest frequency, all of them are listed (a multimodal dataset).
How precise are the results?
Values are computed in 64-bit floating point and rounded to 6 decimal
places for display. Inputs must be finite numbers — NaN, inf or stray
text produce an error naming the offending token rather than a silent skip.
Developer & Automation Access
Run it from the terminal
Same engine as this page, headless — via the gizza CLI:
gizza tool descriptive-stats "2, 4, 4, 4, 5, 5, 7, 9"New to the CLI? Get gizza →
Open it by URL
Pre-fill and auto-run this tool with query parameters — the names match the API/CLI:
https://gizza.ai/tools/descriptive-stats/?numbers=2%2C%204%2C%204%2C%204%2C%205%2C%205%2C%207%2C%209Machine-readable descriptor: tool.json — title + parameters JSON Schema for agents.