How to use this calculator
- Enter or choose numbers.
- The mean (average) updates as you type. Use Copy result or Share to keep it.
Formula
Mean = (x₁ + x₂ + … + xₙ) ÷ n
- xᵢ
- each value
- n
- how many values there are
Worked example
- Sum = 12 + 15 + 15 + 18 + 20 + 22 + 35 = 137.
- Mean = 137 ÷ 7 ≈ 19.57.
- Sorted, the middle (4th) value is 18, the median.
- 15 appears twice, more than any other value, so it is the mode.
Mean ≈ 19.57, median 18, mode 15.
What the result means
The mean is pulled up by the 35. When data has outliers, such as incomes or house prices, the median usually describes a “typical” value better.
Assumptions and limits
- With an even count, the median is the mean of the two middle values.
- For a weighted average (values that count differently), multiply each value by its weight, sum, and divide by the total weight; the GPA calculator does this for grades.
Questions
Mean or median: which should I use?
Use the mean for symmetric data without extreme values, and the median when a few very large or small values would distort the picture.
Can there be more than one mode?
Yes. If two values tie for most frequent, both are modes. If nothing repeats, there is no mode.