Mean, Median, Mode Calculator — Find Range, Quartiles & IQR

Enter numbers separated by commas, spaces, semicolons, or new lines. Private by design—everything runs locally in your browser.

Numbers & Actions

Results

Results will appear here after calculation.

Tip: Ctrl/Cmd + Enter runs Calculate.

Understanding the Statistical Measures

This tool provides a comprehensive set of statistical measures to help you understand your dataset. All calculations are performed client-side in your browser, ensuring your privacy.

Measures of Central Tendency

These values describe the central position of a dataset.

  • Mean (Average): The sum of all values divided by the number of values. It is sensitive to outliers.
  • Median: The middle value of a sorted dataset. It is not affected by outliers.
  • Mode: The value that appears most frequently. A dataset can have one, many, or no modes.

Measures of Spread

These values describe how spread out the data points are.

  • Range: The difference between the maximum and minimum values. $$ \text{Range} = \text{Max} - \text{Min} $$
  • Quartiles (Q1 & Q3): The values that divide the sorted dataset into four equal parts.
    • First Quartile (Q1): The median of the lower half of the dataset.
    • Third Quartile (Q3): The median of the upper half of the dataset.
  • Interquartile Range (IQR): The range of the middle 50% of the data. It is the difference between the third and first quartiles. $$ \text{IQR} = \text{Q3} - \text{Q1} $$

We also provide the total number of values (Count) and their sum (Sum), along with the smallest (Minimum) and largest (Maximum) values.

Frequently Asked Questions

Which separators can I use?

Commas, spaces, semicolons, or new lines. Extra whitespace is ignored.

How are quartiles and IQR computed?

We sort your numbers; Q1 is the median of the lower half, Q3 the median of the upper half, and IQR = Q3 − Q1.

What if there is no mode?

If every value appears once, there is no mode and we’ll say so.

Is my data private?

Yes—calculations run entirely in your browser.

5 Fun Facts about Mean, Median & Mode

One outlier can drag the mean

Add a single giant value (say, a billionaire’s income) and the mean leaps upward—even if every other number stays small.

Outlier power

Medians are traffic reporters

Highway speed signs often show the median speed, not the mean—because medians ignore a few reckless drivers or slow trucks.

Robust pick

Modes work on words

Mode isn’t just numeric: the most common baby name, T-shirt size, or hex color in a pixel array is a mode, too.

Beyond numbers

IQR defines “box plot” whiskers

Classic box plots flag outliers at 1.5×IQR beyond Q1 or Q3—the middle 50% is literally the box.

Visual stats

Simpson’s paradox flips stories

Combine groups and a mean or median trend can reverse direction—always check subgroups before trusting a headline.

Group caution

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