When to use this calculator
Estimate variance using N minus one for a supplied sample. Requires at least two observations and an appropriate independent-sampling interpretation.
Explore the descriptive statistics calculators for other questions in this topic. For a related calculation, use the Statistics Calculator: Summarise a numeric dataset with its count, mean, median, minimum and maximum.
PUTTING IT INTO PRACTICE
Sample Variance: a worked example
The values below are an illustrative example, not a recommendation. Replace them with measurements or assumptions that match your question.
| Input | Example value |
|---|---|
| Data values | 1,2,3 |
| Result | 1 squared input units |
- Check the input labels and enter the example values above.
- Apply the relationship: Sample variance = sum((value − mean)²)/(N − 1)..
- The result is 1 squared input units, rounded for display.
How to interpret your result
Requires at least two observations and an appropriate independent-sampling interpretation.
The mean, median, range and standard-deviation tools accept variable-length lists with their limits stated. Choose a sample or population denominator appropriately. A summary statistic does not validate the sampling process or explain causation.
Frequently asked questions
Should I use sample or population standard deviation?
Use population deviation for the complete population being described. Use the sample form when estimating variability from a sample under suitable assumptions.
When is the sample variance calculator useful?
Estimate variance using N minus one for a supplied sample. Requires at least two observations and an appropriate independent-sampling interpretation.
How do I use the sample variance calculator?
Enter data values. The result updates automatically. Use the units shown beside each input; the example values illustrate the method.
Which formula does this calculator use?
Sample variance = sum((value − mean)²)/(N − 1)..
What should I check before using the result?
Requires at least two observations and an appropriate independent-sampling interpretation.
How are results rounded?
Scalar numbers display up to six decimal places, with scientific notation for very large or small values. Text, fraction, date and schedule outputs use the format described on the tool. Intermediate calculations use JavaScript floating-point arithmetic. Keep sensible precision for your measurements.
Further reading
For background on this topic, see NIST: exploratory data analysis ↗. This is a topic reference, not an external review or endorsement of this tool.
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