What each statistic means
| Statistic | Meaning |
|---|---|
| Mean | The average: the sum divided by the count. Pulled up or down by extreme values. |
| Median | The middle value when sorted. Better than the mean for skewed data such as salaries or house prices. |
| Mode | The most frequent value or values. |
| Standard deviation | How far values typically are from the mean, in the same units as the data. |
| Variance | The standard deviation squared. |
| Standard error | How precisely the sample mean estimates the true mean. Shrinks as the sample grows. |
| 95% confidence interval | The range that would contain the true mean in 95% of samples, using the t-distribution. |
| Quartiles and IQR | Q1 and Q3 cut off the lowest and highest quarter; the interquartile range between them holds the middle half of the data. |
| Skewness | Asymmetry. Positive means a long tail of high values; negative, a long tail of low values. |
| Kurtosis | Excess kurtosis compares the tails with a normal distribution: above 0 means more extreme values than normal. |
| Outliers | Values below Q1 − 1.5 × IQR or above Q3 + 1.5 × IQR, the rule used for box plots. |
Sample or population?
If your numbers are a sample from a larger group (survey answers, a test batch, last month's orders), keep Sample: variance is divided by n − 1, which corrects for the sample being slightly less spread out than the whole group. Choose Population only when you have every value, such as the scores of everyone in a class. This matches Excel's STDEV.S and STDEV.P.
Pasting data
Copy a column from Excel or Google Sheets and paste it straight in. Numbers can be separated by new lines, commas, spaces, tabs or semicolons, and currency symbols and percent signs are ignored. Anything that isn't a number is skipped and listed so you can check it. Working with a whole file instead? The CSV viewer profiles every column at once, and the chart maker draws histograms of any column.
Frequently asked questions
How do I calculate standard deviation?
Paste your numbers above. The calculator gives the sample standard deviation (dividing by n − 1, like STDEV.S in Excel) by default; switch to “Whole population” for STDEV.P.
What is the difference between mean and median?
The mean is the arithmetic average; the median is the middle value. With skewed data or outliers the two differ, and the median is usually the better “typical” value.
How are quartiles calculated?
With linear interpolation between sorted values, the same method as Excel’s QUARTILE.INC and PERCENTILE.INC.
How are outliers detected?
Values more than 1.5 times the interquartile range below Q1 or above Q3 are flagged as outliers, the same rule box plots use.
Is there a limit on how many numbers I can paste?
No fixed limit; hundreds of thousands of values work fine. Everything is calculated in your browser.