Variance Calculator

Calculate the average squared spread using sample or population variance. Enter your own values below to see variance and check the method behind it.

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Your inputs

Change the example values to match your situation.

Your result

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Fill in your inputs and select Calculate.
Your result and breakdown will appear here.

How this calculator works

Variance = sum of squared deviations from the mean ÷ N (population) or N−1 (sample). Standard deviation is its square root.

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What is Variance Calculator?

Variance Calculator helps you calculate the average squared spread using sample or population variance.

The main result is variance, with a breakdown of mean, count and standard deviation. The formula, example and assumptions below explain how to interpret it.

How to use Variance Calculator

Use the example to get familiar with the form, then enter your own figures. Any rates in the example are illustrative. Check the field labels and units before calculating.

  1. Gather data values and dataset type. Use values from the same situation or reporting period.
  2. Replace the example data values with your own value, then complete the other fields. Check the displayed units and each selected option.
  3. Select Calculate and read variance with its result breakdown. Change one input and calculate again to compare a second scenario. Reset restores the original example.
  • Enter data values in the format shown by the example. Keep the same separators and row structure.
  • Choose dataset type from Whole population and Sample.

Variance Calculator: a worked example

With the inputs below, the result is 4 (variance). Follow the example, then replace these illustrative values with your own.

Example inputs and output
Input or outputExample value
Data values2, 4, 4, 4, 5, 5, 7, 9
Dataset typeWhole population
Variance4
Mean5
Count8
Standard deviation2

Understanding the Variance result

Read variance alongside mean, count and standard deviation. These describe different parts of the same calculation.

Displayed results use a readable number of decimal places. When checking a result by hand, keep extra precision until the last step. To compare scenarios, change one input at a time and keep the others fixed.

  • Example Mean: 5
  • Example Count: 8
  • Example Standard deviation: 2

Variance Calculator: assumptions and common mistakes

A useful estimate starts with the right inputs. Check the following assumptions and limits before applying the result to your situation.

  • Check the base value, sample definition and chosen operation. Display rounding should come after the calculation.

For wider guidance, visit NIST statistical handbook. The formula and scope of this specific tool are stated on this page.

Variance Calculator FAQs

What does Variance Calculator calculate?

Variance Calculator helps you calculate the average squared spread using sample or population variance. Its main output is variance.

What inputs do I need for Variance Calculator?

You need data values and dataset type. Use the field labels and units to match your figures to the formula.

Which formula does Variance Calculator use?

Variance = sum of squared deviations from the mean ÷ N (population) or N−1 (sample). Standard deviation is its square root.

What is a worked example for Variance Calculator?

Example inputs: Data values: 2, 4, 4, 4, 5, 5, 7, 9; Dataset type: Whole population. The result is 4 (variance).

How should I enter data values?

Enter data values in the format shown by the example. Keep the same separators and row structure.

How do I choose dataset type?

Choose dataset type from Whole population and Sample. The example uses Whole population; replace it if your circumstances differ.

How should I read variance?

Read variance alongside mean, count and standard deviation. These describe different parts of the same calculation.

Why might my Variance Calculator result differ from my records?

Check the base value, sample definition and chosen operation. Display rounding should come after the calculation. Differences in entered values, units or rounding can also change the comparison.

Can I compare two scenarios in Variance Calculator?

Yes. Note your first variance, change data values or another input, and select Calculate again. Editing a field clears the old result so it is not mistaken for a new calculation.

Is Variance Calculator free, and where are my inputs calculated?

This calculator is free to use without signing in. Its formula runs in your browser; calculator inputs are not sent to a calculation API. The inputs reset to the example values when you reset the form or start a fresh page.