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Standard Deviation Calculator

Population and sample standard deviation and variance for a list you type.

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Results

How to use Standard Deviation Calculator

  1. Enter numbers. Leave a field blank only when the page says the value is missing, not by typing 0 unless 0 is a real value.
  2. Read the result rows under the form. Errors appear in the status line. Nothing is uploaded.
  3. Rounding follows IEEE floating point in this browser unless the page says it uses integers or BigInt.

Standard Deviation Calculator

Population SD

ComputesPopulation and sample standard deviation and variance for a list you type.
IncludesPopulation SD
IncludesSample SD
Enginestats
UploadNone
AdviceArithmetic only

What Standard Deviation Calculator is

Variance is the mean of squared deviations from the mean. Population divides by n. Sample (Bessel) divides by n − 1. SD is the square root. Sample needs at least two numbers.

The formula runs in this tab. CZNull does not receive the numbers.

How this page computes

A single z from a known mean and SD is the z-score page. This page does not assume a normal curve beyond the formula.

Entities and related jobs

Population and sample standard deviation and variance for a list you type. Named features: Population SD, Sample SD.

See also Variance Calculator, Average Calculator, Z-Score Calculator, Median and Mode.

Use cases

Lab repeats, exam spread, and process control. It does not plot a histogram.

Limits

Invalid input appears in the status line. IEEE floating point applies unless a row says otherwise. CZNull does not receive the numbers.

Standard Deviation Calculator questions

Does this page upload my numbers?
No. The formula runs in the page you opened. CZNull does not receive the values.
What does Standard Deviation Calculator compute?
Variance is the mean of squared deviations from the mean.
Why is this its own URL?
Search queries name this job. Nearby modes stay on their own pages so inputs do not mix. Related calculators are linked below Standard Deviation Calculator.
Population or sample?
Population divides by n. Sample divides by n − 1.
Is this a p-value?
No. Only SD and variance.
Can I treat the result as official?
No. Rounding and real-world rules can differ. Use the page to check the arithmetic.