Descriptive statistics turn a raw list of numbers into a summary you can read at a glance.
About this calculator
Descriptive statistics turn a raw list of numbers into a summary you can read at a glance. Paste exam scores, sales figures, survey responses, or sensor readings as comma-separated values. The calculator returns count, mean, median, mode, min, max, range, sum, sample variance, and sample standard deviation.
Mean is pulled by outliers; median resists them. Mode shows the most common value — useful for categorical-coded numbers. Standard deviation measures spread: low SD means values cluster near the mean, high SD means wide scatter. This tool uses sample formulas (n − 1 in variance) which match what most textbooks and Excel teach for data drawn from a larger population.
For a focused mean/median/mode view try the [[mean-median-mode]] calculator. For z-scores and normal distribution comparisons use the [[z-score]] calculator. For survey planning and margin of error see the [[sample-size]] calculator. The [[standard-deviation]] calculator explains spread in more detail with worked steps.
Common uses
- Summarise exam or test score lists for a class report
- Check spread and central tendency of monthly sales or revenue figures
- Quick descriptive stats on survey or experiment data before deeper analysis
- Compare two data sets by mean and standard deviation side by side
- Homework verification for mean, median, mode, and SD calculations
Frequently asked questions
What is the mean of 12, 15, 18, 12, 22?
Sum = 12 + 15 + 18 + 12 + 22 = 79. Count n = 5. Mean = 79 / 5 = 15.8. Enter the full list in the data set field and the calculator confirms mean, median, mode, and all other stats.
Why does standard deviation use n − 1 instead of n?
Sample standard deviation divides by n − 1 (Bessel
What if my data set has more than one mode?
The calculator lists every value that ties for highest frequency. A uniform data set may have no mode — the output shows a dash. Bimodal or multimodal sets are common in real data and are reported fully.
How do I enter negative numbers or decimals?
Type them directly: -3, 4.5, -12.75. Separate with commas. Spaces after commas are stripped. Non-numeric tokens are ignored; make sure at least one valid number remains.
When should I use median instead of mean?
Use median when outliers skew the average — house prices in a city, income distributions, or reaction times with a few extreme values. Mean is fine for symmetric, outlier-free data like repeated lab measurements under controlled conditions.