Average Calculator
The average, or arithmetic mean, collapses a set of numbers into a single representative figure: add them all up and share the total equally. This average calculator handles up to six numbers and shows the mean along with the count and the sum, so you can see exactly how the answer was built. Use it for test scores, monthly bills, daily step counts, or any time you want the typical value of a handful of numbers without reaching for a spreadsheet.
Calculate
Default result: 5.0000
Average Calculator · Result
calculators.dev
Average (mean)
2 × 4 × 9
- How many values
- 3
- Sum of values
- 15.0000
Reviewed by the calculators.dev team · Last updated 2026-06-23
How to calculate
Type your numbers into the value boxes — at least two, up to six — and leave the rest blank. The calculator counts how many you entered, adds them into a running total, and divides that total by the count. For 2, 4, and 9 the sum is 15 and the count is 3, so the mean is 5. Because blank boxes are simply skipped, averaging two numbers works exactly the same as averaging six. The result recalculates as soon as you change any value.
mean = (sum of the values) ÷ (how many values there are). Every number counts equally — the mean is the total divided by the count, with no weighting. This is the arithmetic mean; the median (the middle value) and the mode (the most common value) are different kinds of average that this calculator does not report.
Example calculation
To average 2, 4, and 9, add them to get a total of 15, then divide by how many numbers there are — three. Fifteen divided by three is 5, so the mean is 5. Notice that the mean need not be one of the original numbers; it is the single value that, repeated three times, would give the same total.
- mean
- 5
- count
- 3
- sum
- 15
Assumptions
- Each value is weighted equally — the plain mean treats every number the same, unlike a weighted average where some count more.
- Blank boxes are ignored, so only the numbers you actually enter are included in the count and the sum.
- The mean is sensitive to outliers: one very large or very small value can pull it away from the typical figure.
Common mistakes
- Dividing by the wrong count — including or skipping a blank box changes both the sum and the divisor.
- Reaching for the mean when the median would describe the data better, such as with skewed incomes or house prices.
- Averaging numbers that are already averages or rates, which can mislead unless each is weighted by its size.
Frequently asked questions
How do I calculate an average?
Add all the numbers together, then divide by how many numbers there are. The average of 2, 4, and 9 is (2 + 4 + 9) ÷ 3 = 5.
Is the average the same as the mean?
In everyday use, yes — this calculator finds the arithmetic mean. Statisticians also use the median and the mode as other kinds of average.
Why is my average not one of the original numbers?
The mean is a balance point, not a member of the set. The average of 2, 4, and 9 is 5, even though 5 is not in the list.
Can the average be affected by one extreme value?
Yes. A single very high or very low number can pull the mean away from the typical value, which is why the median is sometimes preferred for skewed data.