Average Calculator
Paste or type your numbers — from a spreadsheet column, a receipt or a set of test scores — and get the mean with the working shown.
Average of a list
The formula
mean = (x1 + x2 + … + xn) ÷ n
- xi
- each value in the list
- n
- how many values there are
“Average” in everyday speech almost always means the arithmetic mean: add everything up and share it out equally. The mean is the balance point of the data — the sum of the distances above it equals the sum of the distances below it.
Worked example
Average of 12, 15, 11, 18 and 14
- Add the values: 12 + 15 + 11 + 18 + 14 = 70
- Count them: there are 5 values
- Divide: 70 ÷ 5 = 14
The average is 14.
Mean or median?
The mean uses every value, which makes it sensitive to outliers. The mean of 20, 22, 24 and 200 is 66.5, although three of the four values are near 22. In skewed data such as house prices or waiting times, the median is often the more representative “middle”. This calculator shows both so you can compare.
Useful properties
- Adding the same amount to every value adds that amount to the mean.
- The mean of several groups is not the mean of their means unless the groups are the same size — use a weighted average instead.
- To find what the next value must be to reach a target average: target × (n + 1) − current sum.
Common questions
Can I average negative numbers and decimals?
Yes. Negative values, decimals and E notation (such as 2.5e3) are all accepted.
How many numbers can I enter?
Thousands. The calculation runs in your browser, so very long lists may take a moment on older devices but nothing is uploaded.