Average Calculator
Find the mean, median, mode, sum and count of a list of numbers, with a worked example showing how one outlier moves the mean far more than the median.
Results
Mean
- Median
- 18
- Mode
- 15
- Count
- 7
- Sum
- 127
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Educational estimates · not financial advice · free, no signup
Formula / how it works
Mean = sum ÷ count. Median = middle value of the sorted list (average of the two middle values if the count is even). Mode = the most frequent value.
Detailed guide
What it is, how to use it, how to read the numbers, common mistakes, a worked example, formulas, and FAQs.
What this calculator is
"Average" can mean several things. The mean adds the numbers and divides by the count; the median is the middle value when they are sorted; the mode is the value that occurs most often. Each answers a slightly different question, which is why this calculator gives all three, along with the sum and the count. The mean uses every value but is pulled by extremes, so a few very large numbers can drag it up. The median is more resistant to outliers, which is why it is used for incomes and house prices. The mode is useful for categories or repeated values. Enter numbers separated by commas or spaces.
When to use / who it helps
- You are summarising test scores, prices or measurements.
- You want to see whether outliers distort the mean.
- You are checking a spreadsheet calculation.
- You are completing statistics homework.
- You need the most common value in a list.
How to use
Steps
- Enter your numbers separated by commas or spaces.
- Read the mean.
- Read the median and mode.
- Check the count and sum.
- Compare the mean with the median.
- Remove outliers only if you have a good reason.
How to interpret results
- If the mean is above the median, the data may be skewed upward.
- The median is the typical middle value.
- The mode may not be unique or may not exist.
- The count confirms how many numbers were read.
- The sum is the numerator of the mean.
Common mistakes & gotchas
- Including text or stray characters in the list.
- Using the mean for skewed data like incomes.
- Forgetting to sort when finding the median by hand.
- Missing a value when counting.
- Assuming a mode always exists.
Worked example
Worked example — 12, 15, 15, 18, 20, 22, 25
- Sum: 12 + 15 + 15 + 18 + 20 + 22 + 25 = 127, and the count is 7.
- Mean: 127 ÷ 7 = 18.142857.
- Median: the 4th of the 7 sorted values is 18. Mode: 15 appears twice.
- Add an outlier of 200: sum 327, count 8, mean 40.875, while the median becomes (18 + 20) ÷ 2 = 19.
Result: Mean 18.14, median 18, mode 15, count 7 and sum 127.
To load the form's own demo values, tap Try example above the Calculate button.
How to calculate / formula
Mean = sum ÷ count. Median = middle value of the sorted list (average of the two middle values if the count is even). Mode = the most frequent value.
Frequently asked questions
What is the difference between mean and median?
The mean is the sum divided by the count; the median is the middle value.
When should I use the median?
When data has outliers or is skewed.
Can there be more than one mode?
Yes.
What if the count is even?
The median is the average of the two middle values.
Does the order of numbers matter?
No.
Can I enter decimals?
Yes.