How to calculate an average
The average — properly called the mean — is the sum of all the values divided by how many values there are:
Mean = Sum of values ÷ Count of values
For the list 4, 8, 15, 16, 23, 42, the sum is 108 and there are 6 numbers, so the mean is 108 ÷ 6 = 18.
Mean vs. median
The mean is the most familiar average, but it can be pulled off-center by outliers — one very large or very small value. The median, the middle number when the list is sorted, ignores how extreme the outliers are and often describes "typical" data better. When the mean and median are far apart, your data is skewed, and the median is usually the figure to quote.
What this calculator shows
- Mean: the arithmetic average.
- Median: the middle value (or the average of the two middle values).
- Sum and count: the total and how many numbers were found.
- Min, max, and range: the smallest and largest values and the gap between them.
Frequently asked questions
How do you calculate the average of numbers?
Add all the numbers together to get the sum, then divide by how many numbers there are. For 4, 8, and 15, the sum is 27 and the count is 3, so the average (mean) is 27 ÷ 3 = 9. This calculator does it instantly for any list you paste in.
What is the difference between mean, median, and mode?
The mean is the sum divided by the count — the everyday "average." The median is the middle value when the numbers are sorted, which is less affected by outliers. The mode is the value that appears most often. This tool shows the mean and median; for skewed data the median is often the more representative figure.
How do you find the median?
Sort the numbers from low to high. If there is an odd count, the median is the middle value. If there is an even count, the median is the average of the two middle values. For 3, 7, 8, 12 the two middle numbers are 7 and 8, so the median is 7.5.
What number formats can I paste in?
Separate your numbers with commas, spaces, or new lines — the calculator accepts any mix. Decimals and negative numbers work too. Anything that is not a valid number is simply ignored, so you can paste a column straight from a spreadsheet.
Tip: You can paste a whole column of numbers copied from a spreadsheet — anything that isn't a valid number is ignored automatically.