Average Calculator

How to use this calculator

Enter your numbers separated by commas, spaces, or new lines. The calculator shows the average (mean), sum, and count up top, plus the median, mode, min, max, and range below. You can paste a column directly from a spreadsheet — any whitespace or commas between values are treated as separators.

How the average (mean) works

The arithmetic mean is the most common way to describe the "center" of a data set. You add all the values together and divide by how many values there are. It is sensitive to outliers: one very large or very small number can pull the mean far from what most people would consider typical. When your data is skewed, the median or mode may give a more honest picture.

There are other types of averages — the geometric mean (used for growth rates and ratios) and the harmonic mean (used for speeds and rates) — but the arithmetic mean is what "average" almost always means in everyday conversation.

Mean vs. median vs. mode

These three measures of central tendency each answer a slightly different question:

• Mean — the balancing point of the data. Best when values are roughly symmetrically distributed without extreme outliers.
• Median — the middle value. Best when the data is skewed or has outliers, such as house prices or salaries.
• Mode — the most common value. Useful for categorical or discrete data, like finding the most popular shoe size.

Worked examples

Example 1 — symmetric data

Data: 10, 20, 30, 40, 50

• Sum = 150, Count = 5, so Mean = 150 ÷ 5 = 30
• Sorted list: 10, 20, 30, 40, 50. Middle value: Median = 30
• Each value appears once, so there is no mode
• Range = 50 − 10 = 40

When data is symmetric and free of outliers, the mean and median are the same (or very close).

Example 2 — data with an outlier

Data: 12, 18, 24, 30, 18, 9, 200

• Sum = 311, Count = 7, so Mean ≈ 44.4
• Sorted: 9, 12, 18, 18, 24, 30, 200. Middle value: Median = 18
• 18 appears twice, so Mode = 18
• Range = 200 − 9 = 191

The single outlier (200) drags the mean up to 44.4, far above six of the seven values. The median of 18 is a far better description of a typical value in this set.

Example 3 — even number of values and the median

Data: 5, 11, 14, 22

• Sum = 52, Count = 4, so Mean = 52 ÷ 4 = 13
• Two middle values are 11 and 14, so Median = (11 + 14) ÷ 2 = 12.5
• Range = 22 − 5 = 17

Common mistakes to avoid

• Confusing mean and median. Reporting the mean when data is skewed can be misleading. If someone asks for the "average" salary but the data includes a few multi-million-dollar earners, the median is a more representative answer.
• Dividing by the wrong count. Make sure you divide by the number of data points, not the number of categories or groups.
• Forgetting to include all values. Accidentally omitting a value changes both the sum and the count, compounding the error.
• Treating the mode as always meaningful. With small or continuous data sets, every value may appear only once, making the mode undefined or unhelpful.
• Mixing up range and standard deviation. The range only looks at two values (max and min), so it is heavily influenced by outliers. Standard deviation considers every value and gives a fuller picture of spread.

The formula

Mean = (x₁ + x₂ + … + xₙ) ÷ n

Median = middle value of sorted list (or average of two middle values if n is even)

Range = Maximum − Minimum