Mean Calculator
Find the arithmetic mean of a list of numbers, with the sum, the count and the working. Geometric and harmonic means are shown too when all your numbers are positive.
Example loaded: 3, 1, 8, 12, 22, 5. Select Clear to enter your own numbers.
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Mean: the quick answer
The mean is the sum of the numbers divided by how many numbers there are.
Example: for 3, 1, 8, 12, 22, 5 the sum is 51 and there are 6 numbers, so the mean is 51 / 6 = 8.5.
How to find the mean
- Add up all the numbers to get the sum.
- Count how many numbers there are.
- Divide the sum by the count: mean = sum / count.
Types of mean
Arithmetic mean is the usual one: sum divided by count. Geometric mean multiplies the n numbers and takes the nth root, and is used for growth rates. For 2, 4 and 8 the product is 64 and the cube root is 4. Harmonic mean is n divided by the sum of the reciprocals, and suits rates such as speed. Driving equal distances at 40 mph and 60 mph gives an average speed of 48 mph.
Mean vs median
One very large number can pull the mean up. In 1, 2, 3, 4, 75 the mean is 17 but the median is 3. Check the median calculator when your data has extreme values, or see all three averages on the mean, median, mode calculator.
Frequently asked questions
Is the mean the same as the average?
In everyday use, yes. Average usually means the mean. Strictly, average can also mean the median or mode. See the average calculator for the everyday version.
How do I find the mean in Excel or Google Sheets?
Type =AVERAGE(A1:A10), changing the range to match your cells.
Do outliers change the mean?
Yes. Every value counts in the sum, so a very large or very small number moves the mean noticeably.
What is the difference between a sample mean and a population mean?
They use the same formula. A population mean covers every item in a group, and a sample mean covers only part of it and is used to estimate the population mean.
Can the mean be a decimal or negative?
Yes. The mean does not have to be in your list, and it is negative if the negatives outweigh the positives.
When should I use the geometric mean?
Use it for growth rates and ratios, such as average yearly growth. It needs numbers above zero.
About this calculator
Written by Umar Khan. The calculator adds your numbers and divides by the count. When every number is above zero it also shows the geometric and harmonic means. Results are shown to up to 10 decimal places (6 for standard deviation) with trailing zeros dropped, and your numbers stay in your browser. Last updated November 9, 2026. Questions or corrections: [email protected].
Written by Umar Khan
Umar Khan is a PhD student in engineering at NTNU, the Norwegian University of Science and Technology, in Norway. Every formula and worked example on this page is shown in full so you can check each result yourself. Corrections are welcome at [email protected].
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For information only, not professional advice.
Written by Umar Khan. Last updated: November 9, 2026.