Mean calculator
Calculator
The calculator needs JavaScript. The tables below give the same numbers for common cases.
How it is worked out
- Add the numbers: 86.
- Divide by the count: 86 ÷ 4 = 21.5.
| Inputs | Answer |
|---|---|
| Numbers: 12, 18, 25, 31 | The mean of 4 numbers is 21.5. |
| Numbers: 4, 8, 15, 16, 23, 42 | The mean of 6 numbers is 18. |
| Numbers: 90, 85, 100 | The mean of 3 numbers is 91.666667. |
How to use it
The mean is the sum of the numbers divided by how many there are. For 12, 18, 25 and 31 the sum is 86 and the mean is 21.5.
The median is shown for comparison: when the two differ a lot, the data is skewed.
Frequently asked questions
How do I calculate the mean?
Add all the numbers and divide by the count.
Is mean the same as average?
In everyday use yes; strictly the arithmetic mean is one kind of average.
Does a zero count in the mean?
Yes, zero is a value and counts toward the total and the number of values.
Method: standard arithmetic shown step by step; no outside data is used. Checked 2026-11-12.
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General information only. Results are plain arithmetic on the numbers you enter; check anything important (money, health, school work) against your own records or the official source.