The average (arithmetic mean) is the most common summary of a set of numbers (test scores, monthly spending or daily steps). Comparing it with the median shows whether a few very large or very small values are pulling it up or down.
How to use the Average Calculator
- Type the numbers separated by commas, spaces or new lines.
- Read the result; it updates as you type.
Results update as you type, and everything is calculated in your browser.
How it works
The numbers are added and divided by how many there are. The median sorts the list and takes the middle value (or the mean of the two middle values). The geometric mean multiplies the values and takes the n-th root; it needs positive numbers.
What each result means
- Average (mean) = mean([List of numbers to average])
- Sample size (count) = count([List of numbers to average])
- Sum = sum([List of numbers to average])
- Median = median([List of numbers to average])
- Largest value = max([List of numbers to average])
- Smallest value = min([List of numbers to average])
Formula
Mean = (x₁ + x₂ + … + xₙ) ÷ n
Median = middle value of the sorted list
Worked example
Inputs: List of numbers to average: 12, 15, 9, 22, 18, 15, 30.
Results: Average (mean) = 17.285714; Sample size (count) = 7; Sum = 121; Median = 15; Geometric mean = 16.167089; Largest value = 30; Smallest value = 9.
Key terms
- Mean
- The sum divided by the count.
- Median
- The middle value of a sorted list.
Frequently asked questions
How do I calculate an average?
Add the numbers and divide by how many there are.
What is the difference between mean and median?
The mean uses every value; the median is the middle value and ignores extremes.
When should I use the geometric mean?
For growth rates and ratios, such as average investment returns.
Can I average averages?
Only if each group has the same size; otherwise use a weighted average.