Free Statistics Calculator for Mean, Median, Mode, Variance, Standard Deviation, Quartiles, and Outliers

Paste a dataset and get a compact descriptive-statistics report including center, spread, quartiles, sample/population variance, standard deviation, coefficient of variation, and IQR outlier fences.

Browser-basedNo sign-upPrivate local historyStep-by-step

Interactive calculator

Dataset

Primary SD type

Decimal places

Mean—

Median—

Std. deviation—

Paste numeric data.

How to use it

Paste numeric observations into the dataset box.
Choose whether your main SD display should be sample or population.
Calculate and review center metrics first.
Inspect quartiles, IQR, and outlier fences for distribution spread.
Use sample statistics when your data represent a sample from a broader population.

What this calculator includes

1. MeanArithmetic average.

2. Median50th percentile using sorted data.

3. ModeMost frequent value or values.

4. RangeMaximum minus minimum.

5. QuartilesQ1, Q2, and Q3.

6. IQRMiddle-50% spread.

7. Population varianceDivide squared deviations by n.

8. Sample varianceDivide squared deviations by n−1.

9. Standard deviationSquare root of variance.

10. Coefficient of variationSD relative to mean.

11. Outlier fences1.5×IQR lower and upper fences.

12. Data cleanupParse comma, space, semicolon, or line-separated values.

Result checklist

0 / 5 complete

Inputs use the intended units or interpretation.The formula mode matches the problem.The result magnitude is reasonable.I reviewed the shown calculation steps.I will round only at the final step.

Local calculation history

Formula and reference table

Statistic	Formula / definition	Notes
Mean	Σx / n	Sensitive to extreme values
Median	Middle ordered value	Robust center measure
Population variance	Σ(x−μ)² / n	Whole population
Sample variance	Σ(x−x̄)² / (n−1)	Bessel correction
IQR	Q3 − Q1	Middle 50% spread

Quick knowledge check

Why does sample variance usually divide by n−1?

Related calculators

Percentile Calculator Growth Rate Graphing Calculator

Frequently asked questions

What is the difference between sample and population standard deviation?

Population SD divides squared deviations by n, while sample SD uses n−1 to estimate population variability from a sample.

Can a dataset have more than one mode?

Yes. Multiple values can tie for the highest frequency.

How are outliers flagged?

This page uses the common 1.5×IQR fence rule, not a universal definition of an outlier.

Does this replace statistical software?

No. It provides descriptive summaries, not inferential tests, regression diagnostics, or distribution modeling.

Scope and accuracy

Statistics are calculated from the values you enter using browser floating-point arithmetic. Quartile conventions can differ between software packages, so verify the method when exact cross-tool agreement is required.