Summation Calculator
Add a list of numbers and get the sum, count, mean and running details — the sigma (Σ) of your data.
How it works
Σ = x₁ + x₂ + … + xₙ · mean = Σ ÷ n
Summation, written with the Greek capital sigma Σ, simply means adding every value in a list. It is the foundation of averages, totals and most statistics: once you have the sum and how many numbers went into it, the mean is just the sum divided by the count. This calculator also reports the smallest and largest values so you can see the spread behind the total.
Worked example
For the numbers 1 through 10, the sum is 1 + 2 + … + 10 = 55. There are 10 values, so the mean is 55 ÷ 10 = 5.5, with a smallest value of 1 and a largest of 10.
Sources: Summation — Wikipedia
Frequently asked questions
What does the sigma symbol Σ mean?
Σ is the summation sign: it tells you to add up a series of terms. Σxᵢ from i = 1 to n means x₁ + x₂ + … + xₙ, exactly what this calculator computes.
How is the sum related to the mean?
The mean is the sum divided by how many numbers you added. So if you know the mean and the count, the sum is mean × count — the two are two views of the same total.
Can I sum negative numbers and decimals?
Yes. Mix positives, negatives and decimals freely; they’re all added in order, so −3, 1.5 and 4 sum to 2.5.
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This calculator is for educational purposes. Double-check important results before acting on them.