Average Calculator
Calculate mean, median, mode, geometric mean, harmonic mean, summary stats, and weighted average.
Last reviewed: June 2026| Value | Weight |
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What this average calculator returns
This average calculator accepts a pasted list of numbers separated by commas, spaces, tabs, or new lines. Standard mode returns arithmetic mean, median, mode, geometric mean, harmonic mean, count, sum, minimum, maximum, and range. Weighted mode lets you enter value-weight pairs and returns the weighted mean plus total weight.
The arithmetic mean is the everyday "average": add every value and divide by the count. Median sorts the values and reports the middle value, or the average of the two middle values for an even count. Mode reports the most frequent value or "No mode" when every value appears once. Range is maximum minus minimum.
Choosing the right average
Use the arithmetic mean when totals and balance matter, such as average score, average cost per item, or average measurement in a fairly symmetric dataset. Use the median when the data are skewed or contain extreme values, such as home prices, incomes, wait times, or response durations. A single very large or very small value can move the mean much more than the median.
Use mode when repetition matters. For example, the most common rating, selected size, or repeated measurement may be more useful than a mean. Mode can be empty for data with no repeated value, and it can contain multiple values when several values tie for highest frequency.
Geometric and harmonic mean requirements
The geometric mean is useful for multiplicative quantities such as growth factors, ratios, indexes, and normalized rates. It requires all values to be positive, so the calculator displays "Requires all positive" if any value is zero or negative. The harmonic mean is useful for averaging rates when the denominator is the quantity being held constant, such as average speed over equal distances. It requires non-zero values because it uses reciprocals.
How weighted average mode works
Weighted mode multiplies each value by its weight, adds those weighted products, and divides by the total weight. The default weighted example uses values 85, 78, 92, and 74 with weights 0.4, 0.3, 0.2, and 0.1, producing a weighted mean of 83.2 and total weight of 1. Weights can be percentages, course credits, unit counts, frequencies, or any nonnegative scale. They do not have to add to 1; the calculator divides by the total weight automatically.
Worked examples
For the default list 4, 8, 15, 16, 23, 42, the arithmetic mean is 18, the median is 15.5, there is no mode, the geometric mean is 13.965497, the harmonic mean is 10.499524, the sum is 108, and the range is 38. For the list 1, 2, 2, 5, 9, the mean is 3.8, the median is 2, the mode is 2, the geometric mean is 2.825235, and the harmonic mean is 2.163462.
Common mistakes to avoid
Do not average averages unless the groups have the same size. If one class has 10 students and another has 40, average the combined student-level data or use a weighted mean. Do not mix units, such as dollars and percentages, in the same list. Check whether zero means a real value or missing data. Remove or investigate data-entry errors before interpreting the result.
Sources and further reading
For central tendency and outlier context, see the NIST Engineering Statistics Handbook page on measures of location and NIST guidance on outliers. For specialized means, see NIST Dataplot's harmonic mean reference, the BLS discussion of distribution statistics and geometric mean, and Python's statistics module documentation.
Frequently Asked Questions
Quick reference
| Statistic | Best use |
|---|---|
| Mean | Balanced numeric data and totals divided by count. |
| Median | Skewed data or data with strong outliers. |
| Mode | Most common repeated value or category code. |
| Weighted mean | Values that represent different counts, credits, or importance. |