Overview
A descriptive-statistics calculator for a list of numbers: mean, median, mode, both population and sample standard deviation, minimum, maximum, range, count, and sum. Paste numbers in almost any format — commas, spaces, semicolons, or newlines — and every statistic recomputes instantly as you edit.
How It Works
Type or paste your numbers into the text area; the parser splits on any mix of commas, spaces, semicolons, and line breaks and silently skips anything non-numeric. The results grid then shows count, sum, mean, median, mode, population standard deviation, sample standard deviation, the minimum and maximum together, and the range. At least one valid number is required; an empty or unparseable input shows an error prompt instead of zeros.
Step-by-Step Usage Guide
- Paste your dataset into the numbers field.
- Confirm the count tile matches how many numbers you expected.
- Read the mean and median to compare central tendency.
- Choose population or sample standard deviation based on what your data represents.
Technical Specifications & Standards
The two standard-deviation figures are the point of the tool. Population standard deviation divides the squared deviations by n and is the right choice when your data is the entire population; sample standard deviation divides by n − 1 (Bessel's correction) and is the right choice for a sample used to estimate a population — the tool computes and labels both so you cannot pick the wrong one by accident. The median sorts a copy of the data and averages the two middle values for even counts, which is the standard convention. Mode detection counts frequencies and reports every value tied at the maximum; if every value occurs once, it reports 'none (all unique)' rather than inventing a mode. Two honest limitations: the parser drops non-numeric tokens silently, so a stray word in pasted data shrinks the count without a warning, and the mean reported is the arithmetic mean — no trimmed or geometric variants. For large samples the two standard deviations converge, which is why the difference matters most for small datasets.
Targeted Use Cases
- Summarising a set of test scores or survey ratings.
- Getting both standard-deviation variants for a lab report or statistics homework.
- Checking the spread of prices, timings, or measurements before making a decision.
- Finding min, max, and range of a list without sorting it by hand.
Notes & Gotchas
- Check the count tile after pasting — silently skipped tokens reduce it.
- Use the sample standard deviation when your data is a sample; use population only for complete data.
- Remember the mean is sensitive to outliers; compare it with the median for skewed data.
- Keep the raw list somewhere safe; the input is not saved across page reloads.
Frequently Asked Questions
What is the difference between the two standard deviations shown?
Population standard deviation divides squared deviations by n; sample standard deviation divides by n − 1 (Bessel's correction). Use the population figure when your data is complete, and the sample figure when estimating from a sample.
How does it decide the mode?
It counts how often each value appears and reports all values that share the highest frequency. If no value repeats, it reports 'none (all unique)' rather than returning a single arbitrary value.
What separators can I use between numbers?
Any mix of commas, spaces, semicolons, and newlines. Non-numeric tokens are ignored, so tidy your paste if the count tile comes back lower than expected.
Does the tool store my data?
No. The dataset stays in the page's state and the statistics are computed in your browser on every keystroke. Nothing is uploaded, and the input resets when you reload.