Average (Mean) Calculator
Paste a set of numbers to get the mean, median, mode, range, standard deviation and more — with a chart and the working shown — or switch to weighted average and add as many value-and-weight rows as you need.
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How the mean is found
The arithmetic mean
The mean — the everyday "average" — is the sum of all the values divided by how many values there are:
μ = ( Σ xᵢ ) ÷ n
where Σ xᵢ is the sum of every data point and n is the count. For 88, 92, 76, 81 and 95, the sum is 432 and n is 5, so the mean is 432 ÷ 5 = 86.4. It's the right measure when data is roughly symmetric and free of extreme outliers.
Mean, median and mode — which to use
These three "averages" answer different questions. The mean balances all values but is pulled by outliers. The median — the middle value once the data is sorted — ignores how extreme the outliers are, which is why it's preferred for skewed data like incomes or house prices. The mode is simply the most frequent value, useful for categorical or repeated data. This calculator reports all of them at once, along with the range, minimum, maximum and standard deviation, so you can see the full shape of your data.
Weighted average
A plain mean treats every value equally, but often some values matter more than others. A weighted average multiplies each value by a weight, sums those products, and divides by the total weight:
x̄ = Σ( value × weight ) ÷ Σ( weight )
It's exactly how a GPA combines course grades by credit hours, how a portfolio return combines holdings by their size, or how a course grade combines assignments by their percentage weight. Switch to the weighted tab and add a row for each value — there's no limit.
Geometric mean and standard deviation
For growth rates, ratios or percentages that compound over time — like average annual investment returns — the geometric mean (multiply all values, take the nth root) is more accurate than the arithmetic mean, because it accounts for compounding. It's shown automatically when all your values are positive. Standard deviation, meanwhile, measures spread: how far, on average, the values sit from the mean. A small value means tightly clustered data; a large one means it's widely dispersed.
Private by design
Every statistic is computed in your browser as you type — nothing is uploaded, so you can paste sensitive grades, salaries or figures freely. Results are rounded cleanly to avoid the floating-point quirks that plague many web calculators, and the working is shown so you can follow (or teach) each step.
Frequently asked questions
How do you calculate the mean (average)?
Add all the values, then divide by the count: mean = sum ÷ n. For 88, 92, 76, 81, 95 the sum is 432 and n is 5, so the mean is 86.4.
What's the difference between mean, median and mode?
Mean is the arithmetic average; median is the middle value when sorted; mode is the most frequent value. The median resists outliers, so it's better for skewed data like incomes.
How do you calculate a weighted average?
Multiply each value by its weight, sum the products, and divide by the total weight: Σ(value × weight) ÷ Σ(weight). It's how a GPA weights grades by credit hours.
What is the geometric mean and when is it used?
Multiply all values and take the nth root. It's the correct average for compounding growth rates and ratios, such as average annual returns. Positive numbers only.
What does standard deviation tell you?
How spread out the data is around the mean — small means tightly clustered, large means dispersed. It's the square root of the variance.