Math & Number Tools Calculator

Statistics Calculator

Use this free Statistics Calculator to calculate statistics with a cleaner layout, instant results, formulas, examples, and helpful interpretation notes.

Explore your data set

Separate values with commas, spaces, semicolons or new lines. For decimal commas, put each value on a new line or separate values with semicolons. Up to 500 values.

Your statistics

Data distribution

The chart shows your values and marks the mean and median. For larger data sets it becomes a histogram.

ValuesMeanMedian
Mean versus median · Absolute difference

A large gap can signal skew or influential values. Compare the two, then inspect the chart and raw data before drawing conclusions.

Quartiles and possible outliers

The box spans Q1 to Q3. Whiskers end at the most extreme non-outlier values; points beyond 1.5 × IQR are flagged for review.

Possible outlier

Quartiles use the median-of-halves method; for an odd count, the overall median is excluded from each half.

How each result was calculated

Sorted values

Value frequencies

ValueFrequencyShare

Your statistics: A ↔ B

ValueABB − A

Data distribution: A / B

How each result was calculated

Choose population when the data includes every member of the group of interest. Choose sample when the data is a subset used to estimate a larger group; sample variance divides by n − 1.

Quartiles use the median-of-halves method; for an odd count, the overall median is excluded from each half.

Sample (n − 1)

Count: n = 6 · Sum: 12 + 15 + 15 + 18 + 22 + 30 = 112
Mean: 112 ÷ 6 = 18.6667
Median: (15 + 18) ÷ 2 = 16.5
Variance: Σ(x − x̄)² ÷ (n − 1) = 42.2667
Standard deviation: √42.2667 = 6.5013

With one value, n − 1 is zero, so sample variance and sample standard deviation are undefined.

Standard deviation FAQ

Should I choose population or sample?

Choose population when the data includes every member of the group of interest. Choose sample when the data is a subset used to estimate a larger group; sample variance divides by n − 1.

Does a value outside two standard deviations mean an error?

No. It is only a large standardized deviation in this data set. Investigate the value and the distribution before interpreting it.