SD
Standard Deviation Calculator
Enter a list of numbers — instantly find the mean, variance and standard deviation (population or sample).
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Input
Result
—
Standard Deviation
Count (n)—
Mean (average)—
Variance—
Sum—
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How to use — Standard Deviation Calculator
- Paste your numbers — separated by comma, space, or new line.
- Choose Sample or Population type (keep Sample as default if unsure).
- Get the mean, variance, and standard deviation instantly.
FAQ
What does standard deviation tell you?
How spread out the data is around the mean (average). A low SD means values are close to the mean, a high SD means they're widely spread.
What's the difference between Sample and Population?
Population = the entire dataset (like the whole class's marks). Sample = a small part of it (like 10 students from the class). The sample formula uses (n-1), which gives a slightly larger estimate (Bessel's correction).
What's the difference between variance and SD?
Variance = the square of SD. SD is more useful because its unit matches the original data (variance's unit is squared).
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