Average Calculator
Mean, median and mode side by side — plus weighted averages, sorted data, and a quick visual chart.
Calculate
Each value with its weight — e.g. exam scores and their credit weights.
| Value | Weight | |
|---|---|---|
| Count | 5 |
| Sum | 38 |
| Min / Max / Range | 3 / 12 / 9 |
| Sorted | 3, 7, 7, 9, 12 |
How to Use the Average Calculator
Paste your numbers separated by commas, spaces, or line breaks — or hit Load sample data to explore. The calculator instantly shows all three averages side by side, plus the sorted list (so the median is transparent), the count, sum, range, and a mini bar chart for a quick visual read. Switch to Weighted mode when values count differently: enter each value with its weight, like exam scores with credit weights.
Mean vs Median vs Mode
- Mean — add everything, divide by how many. The familiar "average." Best when data is symmetric with no wild outliers.
- Median — the middle value after sorting. Immune to outliers: in 1, 2, 3, 4, 100, the mean is 22 but the median is 3.
- Mode — the most frequent value. The only "average" that works for categories (favorite color, most common shoe size).
Seeing all three together is the point: when they agree, any of them describes the data well. When they disagree, the shape of the disagreement tells you something — a mean far above the median means a right-skewed distribution with high outliers pulling it up.
Worked Example
Dataset: 3, 7, 7, 9, 12.
Mean: (3 + 7 + 7 + 9 + 12) ÷ 5 = 38 ÷ 5 = 7.6.
Median: sorted → 3, 7, 7, 9, 12. Middle (3rd of 5) = 7.
Mode: 7 appears twice, everything else once → 7.
Here all three cluster around 7 — a well-behaved dataset. Now change the 12 to 120: the mean jumps to 29.4, the median stays 7, and the mode stays 7. That single edit demonstrates why news reports about income use the median — one billionaire shouldn't define "typical."
When Each Measure Matters
- Use the mean for symmetric data: test scores in a well-taught class, heights, measurement averages in science.
- Use the median for skewed data: incomes, house prices, wait times — anywhere a few extremes distort the picture.
- Use the mode for categories or peaks: most common defect type, busiest hour, popular vote.
A classic trap: "average" customer ratings. A product with ratings 5, 5, 5, 1, 1 has a mean of 3.4 — but nobody actually feels "3.4" about it. The distribution is bimodal (modes 5 and 1): people love it or hate it. Always glance at the shape, not just the single number.
Weighted Average: A Quick Intro
When some values matter more than others, weight them:
Example: you scored 80 on a midterm (weight 2) and 90 on the final (weight 3). Weighted average = (80×2 + 90×3) ÷ (2+3) = (160 + 270) ÷ 5 = 86 — not the simple mean of 85, because the final counted more. GPA is a weighted average (credits are the weights), investment returns are weighted by position size, and course grades are weighted by assignment categories. Try your own numbers in the Weighted tab above.
My saved numbers reuse them in any calculator
Save a number once — like your rent or hourly rate — then just type its name instead of the number, in any calculator here. You can also type formulas like 5000 * 1.1 right into any box.
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Frequently Asked Questions
How do you find the average of numbers?
The most common average is the mean: add all the numbers and divide by how many there are. For 3, 7, 7, 9, 12: (3+7+7+9+12) ÷ 5 = 38 ÷ 5 = 7.6.
What is the difference between mean and median?
The mean is the arithmetic average (sum ÷ count); the median is the middle value when data is sorted. The median resists outliers: in 1, 2, 3, 4, 100, the mean is 22 but the median is 3 — the median better reflects a "typical" value here.
How do I calculate a weighted average?
Multiply each value by its weight, add those products, then divide by the total weight: Σ(value × weight) ÷ Σ(weights). Example: exam scores 80 (weight 2) and 90 (weight 3): (160 + 270) ÷ 5 = 86.
What is the mode?
The mode is the value that appears most often. In 3, 7, 7, 9, 12, the mode is 7. A dataset can have no mode (all values unique) or several modes (a tie for most frequent).
Can you average negative numbers?
Yes — the math works the same. For −4, 2, 8: (−4 + 2 + 8) ÷ 3 = 6 ÷ 3 = 2. Just be careful with the median: sort first (−4, 2, 8), then take the middle.