Mean Calculator
Calculate the arithmetic mean of any set of numbers.
Enter comma-separated values and get the mean instantly with sum and count shown for verification.
Mean (Average)
Mean = (x1 + x2 + x3 + ... + xn) / n
The arithmetic mean is the most widely used measure of central tendency, commonly called “the average.” You add up all the values and divide by how many values there are.
What the variables mean:
- x1, x2, … xn – the individual numbers in your data set
- n – the total count of numbers
When to use the mean: The mean is useful whenever you want a single number that represents the “typical” value in a data set. Common uses include calculating grade averages, average temperatures, average prices, and sports statistics.
Practical examples:
- Test scores: If your scores are 85, 90, 78, 92, and 88, the mean is (85+90+78+92+88)/5 = 86.6
- Daily temperatures: Monday through Friday temperatures of 72, 75, 68, 70, 80 give a mean of 73 degrees.
Tips and common mistakes:
- The mean is sensitive to outliers. One very high or very low value can pull the average significantly. For example, incomes of $40K, $45K, $50K, $42K, and $500K produce a mean of $135.4K, which does not represent the typical person in the group.
- When outliers are present, the median (middle value) is often a better measure of center.
- Do not confuse the mean with the mode (most frequent value) or the median (middle value when sorted).
- Enter numbers separated by commas. The calculator shows both the sum and the count for verification.
- The mean works with negative numbers too – they simply reduce the sum.