Average Calculator
Find the average of any list of numbers: count the values, add them up, and divide by how many there are.
Average Calculator — input your values
What does this math calculator do?
The average calculator takes any list of numbers — separated by commas or spaces — and computes the arithmetic mean in three transparent steps: count the values, add them together, and divide the sum by the count.
The mean is the most common measure of central tendency: it is the value that balances the data set, and it is what people usually mean by 'average'. The tool also reports the count and the total, and it charts your values so you can see the spread at a glance.
Formula and variables
| Symbol | Meaning |
|---|---|
| x₁ ... xₙ | The values in the list |
| n | The number of values |
| average | Also called the arithmetic mean |
Worked example
A student scored 85, 92, 78, 96, and 88 on five quizzes. What is the average?
- Sum the scores: 85 + 92 + 78 + 96 + 88 = 439.
- There are 5 scores, so divide: 439 ÷ 5 = 87.8.
Answer: The average score is 87.8.
Tips and common mistakes
Tips
- For a quick estimate, average the largest and smallest values — the true mean will be close when the data is evenly spread.
- The mean is sensitive to outliers: one extreme value can pull it far from the center of the data.
- If values repeat, you can use the shortcut: multiply each distinct value by its frequency before summing.
- Check your total by estimating: the average must always lie between the smallest and largest values.
Common mistakes to avoid
- Dividing the sum by the wrong count after removing or duplicating values.
- Including empty entries or stray punctuation in the list, which this calculator rejects with a clear message.
- Using the median when the question actually asks for the mean — they are different measures of center.
Average Calculator — frequently asked questions
What is the difference between average and mean?
In everyday language they are the same: the arithmetic mean, computed as the sum divided by the count. Strictly speaking, 'average' can also refer to median or mode.
How do I enter my numbers?
Type them separated by commas, spaces, or both — for example: 12, 15, 20, 9 or 12 15 20 9.
What if my list contains an outlier?
The mean will be pulled toward the outlier. If that happens, the median may describe the typical value better — see the mean, median, mode calculator.
Can I average negative numbers?
Yes. Negative values are subtracted from the total, and the average can be negative or zero.
What is a weighted average?
A weighted average multiplies each value by its importance (weight) before summing and divides by the sum of the weights. It is commonly used for grades where assignments count differently.
Why does my teacher sometimes call it 'mean'?
Because the arithmetic mean is the technical name for the average you compute by adding and dividing. It is one of several measures of central tendency.