Mean Calculator
Calculate an equally weighted arithmetic mean, count and sum from finite numbers. Understand units, outliers, missing values and population limits.
What the calculator measures
The arithmetic mean is the sum divided by the number of entered values. Enter finite measurements separated by commas, spaces or new lines, then select Calculate Mean. The tool reports the mean, sum and count. Invalid entries are rejected rather than silently removed.
Each entered value gets equal weight. Category codes, identifiers and ordinal responses need attention before arithmetic is meaningful. A blank or missing observation should not be replaced with zero unless zero was actually measured.
Reproduce a worked example
Enter 2, 3, 3, 4, 8. The sum is 20, the count is 5, and the mean is 4. The median of these values is 3; the larger final value pulls the mean upward. Both summaries are correct and describe different aspects of the distribution.
For a combined mean from groups of different sizes, weight the group means by their counts. If ten observations average 4 and thirty average 6, the combined mean is (10×4+30×6)/40=5.5, not 5. Do not enter only the two means into this equally weighted calculator and call the result the pooled mean.
Before interpreting the output
The result has the same units as the entries. It describes these values and does not include a confidence interval, bias correction, robust estimator or assessment of data quality. Inspect the distribution, unusual observations and missingness before generalizing to a population.
Calculations run in the browser. Entered data are not included in analytics. Very large values that produce nonfinite arithmetic are rejected; rescale measurements if needed.
Continue
Read mean and median, inspect descriptive statistics, or work through the guided analysis.
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Our lessons explain the statistical concepts behind this calculator with clear examples.
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