How to Calculate an Average
The most common average is the arithmetic mean: add every value together and divide by how many values there are. Two other measures of center — the median (middle value) and mode (most frequent value) — often tell a more complete story, especially when data is skewed.
Test scores of 72, 85, 90, 85 and 68: the sum is 400 and there are 5 scores, so the mean is 80. Sorted (68, 72, 85, 85, 90) the median is 85, and the mode is also 85 since it appears twice.
Which Average Should You Use?
| Measure | Best when | Watch out for |
|---|---|---|
| Mean | Data is fairly symmetric | Distorted by outliers |
| Median | Data has outliers or skew | Ignores the size of extremes |
| Mode | Finding the most common category | May not exist or be unique |
Frequently Asked Questions
What is the difference between mean, median and mode?
The mean is the sum of all values divided by how many there are. The median is the middle value when the data is sorted (or the mean of the two middle values). The mode is the value that appears most often. Each describes the “center” of data differently.
When is the median better than the mean?
When data has extreme outliers. Average income is a classic case: one billionaire in a small town pulls the mean far above what a typical person earns, while the median barely moves.
Can a data set have more than one mode, or no mode?
Yes to both. If two values tie for most frequent, the set is bimodal. If every value appears exactly once, the set has no mode at all.
How do I calculate a weighted average?
Multiply each value by its weight, add those products, and divide by the total weight. Course grades are a common example — our GPA calculator does exactly this with credit hours as the weights.
Cite This Calculator
Using this calculator in an assignment, article or lesson? Copy a ready-made citation — or the link snippet if you're referencing it from a web page.
The CalculatorsGuide Editorial Team. (2026). Average Calculator. CalculatorsGuide. Retrieved from https://www.calculatorsguide.com/statistics/average-calculator/