Average Calculator

Find the mean, median, mode, or weighted average of any numbers.

Mean, Median, Mode and Weighted Average

"Average" usually means the mean: add all the values and divide by how many there are. But three other averages tell you different things. The median is the middle value when the numbers are sorted — useful when a few extremes would distort the mean, as with house prices or salaries. The mode is the value that appears most often. A weighted average gives some values more importance, as with graded coursework.

When to Use Which

Use the mean for evenly spread data, the median when there are outliers, and the mode for categories or most-common values. If four people earn $30k and one earns $500k, the mean ($124k) is misleading while the median ($30k) describes the group better.

Worked Example

Test scores: 60, 70, 70, 80, 100. Mean = (60+70+70+80+100)/5 = 76. Median = the middle value once sorted = 70. Mode = 70 (appears twice, more than any other value). Notice the mean (76) is pulled upward by the single 100 — with only 5 data points, one outlier shifts the mean more than the median, which is why median is the standard for skewed distributions like income or home prices.

Going Further

For spread and variability — range, variance, and standard deviation — use the statistics calculator.

Frequently Asked Questions

Mean = sum/count; affected by outliers. Median = middle value; robust to outliers. Mode = most frequent value. For skewed data (like salaries), the median is usually the better 'average'.
Multiply each value by its weight, sum the products, then divide by the sum of weights. Example: Exam (weight 60, score 85) + Quiz (weight 40, score 90) → (60×85+40×90)/(60+40) = 87.
The geometric mean is used when comparing things with exponential growth (investment returns, population growth). It's the nth root of the product of n values.