Average Calculator
Enter a list of numbers to get the arithmetic mean in one step — along with the sum, count, minimum, maximum and range. Numbers may be separated by commas, spaces, semicolons or newlines, and negative or decimal values are fully supported. Results update instantly as you type.
Enter your numbers
Enter your numbers and press Calculate average.
How the arithmetic mean is calculated
mean = (x₁ + x₂ + … + xₙ) / n
Every value in the list is added together to form the sum, then divided by how many values there are. The result is the value each item would need to have if all items were equal — which is what makes it useful as a representative "typical" number.
| Symbol | Meaning |
|---|---|
x₁ … xₙ | The individual numbers in the list |
n | How many numbers are in the list |
Sum | x₁ + x₂ + … + xₙ |
Worked examples
Example 1 — Small list
Numbers: 10, 20, 30, 40, 50
Sum = 150. Count = 5. Mean = 150 / 5 = 30.
Average = 30
Example 2 — Test scores
Scores: 72, 85, 91, 68, 94, 78, 88
Sum = 576. Count = 7. Mean = 576 / 7 ≈ 82.29.
Average = 82.29
Example 3 — Numbers with negative values
Numbers: -5, 3, 8, -2, 6
Sum = 10. Count = 5. Mean = 10 / 5 = 2.
Average = 2
Mean, median or mode — which average?
The word "average" is colloquial. Statistically there are three common measures, and they tell different stories:
- Mean — sum ÷ count. Uses every value and is what most people mean by "average". Sensitive to outliers.
- Median — the middle value when the list is sorted. Not affected by extreme values, so it is often more representative when the data are skewed.
- Mode — the value that appears most often. Useful for categorical or repeated data.
If a list contains a small number of extreme values (for example, one very large salary among many modest ones), the mean will be pulled upward. The mean, median, mode and range calculator shows all three for the same dataset, which makes the difference obvious.
Common mistakes
- Dividing by the wrong count. The divisor is how many numbers you entered, not the highest number or the range.
- Forgetting to include zeros. A zero counts as a value and must be included in both the sum and the count — omitting it inflates the average.
-
Mixing separators inconsistently. The calculator accepts
commas, spaces, semicolons and newlines, but a decimal comma (as used in
some European locales, e.g.
3,14) will be read as two numbers. Use a period for decimals. - Averaging percentages by averaging the percentage values. Averaging percentages is only correct if each percentage is based on the same denominator. When they are not, you need a weighted average.
Related calculators
Frequently asked questions
Add all the numbers together, then divide by how many numbers you added. For example, the average of 4, 8 and 12 is (4 + 8 + 12) / 3 = 8.
Any list of integers or decimals, positive or negative, separated by commas, spaces, semicolons or newlines. Zeros are valid values and count toward the total.
In everyday use they mean the same thing. Statistically, "average" can refer to the mean, median or mode, but when used without qualification it usually means the arithmetic mean.
The most common causes are (a) a decimal comma being read as a separator, (b) forgetting to include zeros, and (c) an outlier pulling the mean toward it. The result panel shows the sum, count, min and max so you can spot discrepancies quickly.
Yes — use the weighted average calculator. The arithmetic mean treats every value equally; a weighted average lets some values count more than others.