How to use the average calculator
Enter your numbers as a list separated by commas, spaces, or line breaks. The calculator calculates the mean, median, mode, and range from the same data set. You can also switch to the Weighted Average tab when different values should contribute unequally.
For example, enter 85, 90, 78, 92, 88 to calculate the average of five test scores. The calculator sorts the values when finding the median and identifies the value or values that occur most often for the mode.
How to find the average
The arithmetic mean is the most common meaning of "average." Add all the values together to find their sum, then divide the sum by the number of values in the data set.
Mean = Sum of all values ÷ Number of values
Example: 85, 90, 78, 92, 88
Sum = 85 + 90 + 78 + 92 + 88 = 433
Mean = 433 ÷ 5 = 86.6
When people say "average" without qualifying it, they almost always mean this one — add everything up, divide by how many numbers there are.
Mean vs. median — they're not the same "average"
The median is the middle value once everything is sorted — and it can differ substantially from the mean when a data set has extreme outliers.
$40,000, $45,000, $48,000, $50,000, $400,000
Mean = (40,000+45,000+48,000+50,000+400,000) ÷ 5 = $116,600
Median = the middle value once sorted = $48,000
The mean here is pulled far above what four of the five people actually earn, because one large value drags it upward. The median isn't affected by outliers the same way, which is why income, home prices, and similarly skewed data are often reported as medians rather than means — the median better represents a "typical" value when a few extreme numbers would otherwise distort the picture.
For a quick comparison of the center and spread of a data set, you can also use the IQR Calculator or Standard Deviation Calculator.
Mode and range
Mode is the value that appears most often in a data set. A data set can have one mode, multiple modes when values are tied for the highest frequency, or no mode when every value occurs the same number of times.
Range measures the difference between the largest and smallest values:
Range = Maximum − Minimum
Example: 4, 7, 9, 12, 15
Range = 15 − 4 = 11
Range is easy to calculate, but it can be strongly affected by a single unusually large or small value. Measures such as the interquartile range (IQR) describe spread differently by focusing on the middle portion of the data.
Weighted average
A plain average treats every number equally. A weighted average doesn't — some values count more than others, like a final exam worth more of a grade than a single homework assignment.
Weighted Average = Σ(value × weight) ÷ Σ(weight)
Example: exam 90 (worth 30%), homework 85 (worth 20%), final 95 (worth 50%)
= (90×30 + 85×20 + 95×50) ÷ (30+20+50)
= (2,700 + 1,700 + 4,750) ÷ 100
= 9,150 ÷ 100 = 91.5
Note the plain mean of 90, 85, and 95 would be 90 — the weighting shifts the result because the highest-scoring item (the final) counts for half the grade.
If you need to calculate a weighted mean separately, use the Weighted Average Calculator. A plain mean should be used when every value has equal importance.
Which measure of average should you use?
Mean, median, and mode describe the center of a data set in different ways. The best choice depends on the type of data and what you want to understand.
| Measure | How it works | Useful when |
|---|---|---|
| Mean | Add all values and divide by the count | All values should contribute equally |
| Median | Middle value after sorting | Data contains outliers or is skewed |
| Mode | Most frequently occurring value | You want the most common value |
| Weighted average | Values contribute according to their weights | Some values matter more than others |
Other ways to summarize a data set
The mean is only one way to describe a data set. Depending on what you're analyzing, other statistics can provide additional information.
- Weighted Average gives different values different levels of influence.
- Trimmed Mean removes a chosen percentage of the smallest and largest values before calculating the mean.
- Geometric Mean is useful for quantities that combine multiplicatively, such as growth rates.
- Mean Absolute Deviation measures the average distance of values from the mean.
- Interquartile Range measures the spread of the middle 50% of a data set.
- Midrange takes the average of the minimum and maximum values.
Frequently asked questions
How do you find the average of a set of numbers?
Add all the numbers together, then divide by how many numbers there are. Five test scores of 85, 90, 78, 92, and 88 add up to 433; divided by 5, the average is 86.6.
What's the difference between average and median?
Average (mean) adds everything up and divides by the count. Median is the middle value once the numbers are sorted. They're usually close, but a few extreme values can pull the mean well away from what's "typical," while the median stays put — that's why the median is often the more representative figure for things like income or home prices.
What is the difference between mean, median, and mode?
The mean is the sum of all values divided by the number of values. The median is the middle value after sorting the data, and the mode is the value that occurs most often. A data set can have different mean, median, and mode values.
What if there's no mode, or more than one?
If every value in the list appears exactly once, there's no mode — nothing stands out as more frequent than anything else. If two or more values are tied for the most frequent, the data set is multimodal, and all of the tied values are reported as modes.
How do I calculate a weighted average?
Multiply each value by its weight, add those products together, then divide by the total of all the weights. This gives more influence to values with larger weights, unlike a plain average which treats every value the same.
How do you calculate the range?
Subtract the smallest value from the largest value. For example, if the smallest value is 4 and the largest is 15, the range is 15 − 4 = 11.
Can the average be a number that isn't in the data set?
Yes. The mean does not have to be one of the original values. For example, the mean of 2, 4, and 5 is 11/3, or approximately 3.67, even though 3.67 is not in the data set.
Can I paste numbers written with a comma as the decimal (e.g. "1,5")?
Not directly — commas are used to separate numbers in the list, so "1,5" is read as two values, 1 and 5, not one value of 1.5. If you're used to writing decimals with a comma, replace it with a period before pasting (1.5 instead of 1,5), or separate your numbers with spaces or new lines instead of commas.
Does the calculator accept scientific notation (like 1e3)?
No — enter the full number instead (1000 rather than 1e3). This matches how number entry works throughout the rest of the site.