Math & Statistics

Descriptive Statistics Calculator

Summarises a column of numbers with the full set of descriptive measures, sample and population both.

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How to use this tool

  1. Paste your numbers, one per line. Thousands separators, currency symbols and trailing percent signs are read and stripped.
  2. Select Summarise.
  3. Read the summary line first — it says whether the mean and median have parted company, which decides which of the two you should be quoting.
  4. Take the sample row for standard deviation and variance unless you genuinely hold every case in the population.

What descriptive statistics does

Most calculators give you a mean and stop, which is exactly where a distribution starts to mislead. This page reports the median beside the mean, the interquartile range beside the standard deviation, and a skewness figure that says which way the tail runs — so when a handful of large values are dragging the average upwards, the summary line tells you rather than leaving it for you to discover later.

Both divisors are shown. The sample figures use n−1 and are what you want when your numbers are a sample of something larger, which they usually are; the population figures use n and are right only when you genuinely have every case. Spreadsheets pick one silently — STDEV against STDEVP — and quoting the wrong one is a common way to understate variation.

Frequently asked questions

The sample one, with the n−1 divisor, in nearly every case. Population figures are only correct when your numbers are the whole population rather than a sample of it — every order ever placed, not last month’s orders. The sample divisor is slightly larger and is the conservative choice when you are unsure.

It says which way the tail runs. Positive skew means a few unusually large values are pulling the mean above the median, which is the normal shape for response times, order values and file sizes. When skew is high the median is the more honest headline figure, and the summary line says so.

Yes. A leading currency symbol, a trailing percent sign and underscores are stripped, and commas are removed when they sit in genuine thousands positions — so 1,250 reads as one value rather than two. A line that is not a number at all is skipped and counted in the summary.

No. The whole calculation runs in your browser as JavaScript. Nothing is sent to a server, which is what makes it safe to paste figures you would not put into a web form.