Average Calculator
Paste or type a list of numbers to get the mean (average), with the sum and division steps shown.
How to use this calculator
Enter your numbers separated by commas, spaces, or line breaks, then press Calculate. The calculator adds them up, counts them, divides, and shows all three numbers so the result is easy to trust and easy to check.
How it works
The arithmetic mean is the sum of the values divided by how many there are. It is the “fair share” value: if every data point were replaced by the mean, the total would stay the same.
Worked example
Example: test scores 82, 90, 78, 95
Step 1, Add: 82 + 90 + 78 + 95 = 345.
Step 2, Count: n = 4.
Step 3, Divide: 345 ÷ 4 = 86.25.
Answer: the average score is 86.25.
Common mistakes
- Dividing by the wrong n: count the values you actually entered, blank entries and text do not count, and the calculator ignores them loudly rather than silently.
- Mean vs median: one extreme value (a 0 or a 1,000,000) drags the mean but barely moves the median. For skewed data like incomes, the median is usually the fairer “typical” value.
- Averaging averages: the mean of group means is only the overall mean if every group is the same size, otherwise you need a weighted average.
When to use it
Averages summarize grades, race times, monthly spending, temperatures, and any repeated measurement. It is the first statistic most people learn, and the most misused, which is why the calculator shows its work instead of just a number.
Frequently asked questions
Add all the numbers together and divide by how many there are. For 82, 90, 78, 95: (82+90+78+95) ÷ 4 = 86.25.
In everyday language they are the same thing. Technically “average” can also mean median or mode, but unless specified, average means the arithmetic mean.
Yes, when data is skewed. If nine people earn $50k and one earns $5M, the mean income is about $545k, technically correct, but the median ($50k) describes the group better.
Only by weighting them correctly. Averaging 50% (of 10) and 100% (of 1000) as 75% is wrong, the true combined rate is about 95.5%. Convert back to counts first.