VAR.P Function in Excel
Calculate population variance in Excel with VAR.P. Learn syntax, examples, and when to use population vs sample variance for complete statistical analysis.
=VAR.P(number1, [number2], ...)Quick Answer
VAR.P function VAR.P function calculates the variance of a complete population dataset in Excel and Google Sheets. It measures the average squared deviation from the mean for an entire population. Use the syntax `=VAR.P(number1, [number2], ...)` where number1 is your required data range containing at least 2 values representing your complete population.
=VAR.P(number1, [number2], ...)Appropriate VAR.P Examples
Complete Class Performance Analysis
Calculate variance for all 25 students in a specific class
Historical Sales Period (Closed)
Analyze variance of all daily sales in completed quarter
Department Headcount Variance
Calculate salary variance for all 12 employees in department
When VAR.P is WRONG (Use VAR.S Instead)
⚠️ WRONG: Sample Survey Results
Don't use VAR.P for survey samples
⚠️ WRONG: Ongoing Production Data
Don't use VAR.P for continuing processes
Common Errors
Division by zero
Fewer than 2 numerical values in the dataset. VAR.P requires at least 2 values to calculate variance.
Verify range contains at least 2 numeric values. Check for empty cells, text entries, or errors. Use COUNT to verify: =IF(COUNT(A1:A10)>=2, VAR.P(A1:A10), "Need at least 2 values")
Add data validation: =IF(COUNT(B2:B100)>=2, VAR.P(B2:B100), "Insufficient data")
Example:
Invalid value type
Range contains error values (#N/A, #REF!, etc.) that cannot be processed.
Clean data by removing errors. Use IFERROR on source data: =VAR.P(IFERROR(A1:A10,"")). This converts errors to blanks which are ignored.
Wrap source calculations: =VAR.P(IFERROR(A1:A10,""))
Example:
Using VAR.P when VAR.S is correct
Most common statistical error: using population variance for sample data. This underestimates true variance and leads to incorrect conclusions, especially in hypothesis testing and confidence intervals.
Ask yourself: "Do I have data for EVERY member of the population I care about, with no intent to generalize?" If answer is anything but a definitive YES, use VAR.S instead. When in doubt, VAR.S is the safer choice.
Default to VAR.S unless you're absolutely certain you have complete population data. Document your reasoning for choosing VAR.P.
Example:
Best Practices
The 90% Rule: Default to VAR.S
In practical business and research applications, VAR.S is the correct choice about 90% of the time. Only use VAR.P when you can definitively state you have every single member of your complete, finite population. When in doubt, use VAR.S - it's the statistically conservative and safer choice.
Document Your Choice
When using VAR.P, document why you chose population variance. Write a note explaining that you have complete population data and aren't making inferences. This helps reviewers understand your statistical reasoning and prevents future confusion. Example note: "Using VAR.P because this is all 25 students in Mr. Smith's 3rd period class, analyzing only this specific class."
Convert to Standard Deviation for Interpretation
Like VAR.S, VAR.P returns results in squared units. For easier interpretation, convert to standard deviation: =SQRT(VAR.P(data)) or use STDEV.P(data) directly. Standard deviation is in original units and much more intuitive to understand and communicate.
The Difference is Small but Critical
For the same data, VAR.P always gives a slightly smaller value than VAR.S. With large datasets (n>100), the difference is minimal, but the conceptual error of using the wrong function affects statistical inference, hypothesis testing, and confidence intervals regardless of sample size.
Peer Review for VAR.P Usage
Before publishing analysis using VAR.P, have a colleague review your choice. It's easy to mistakenly think you have population data when you actually have a sample. A fresh perspective can catch this common error. Ask them: "Do we really have every single member of the population?"
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Example Excel formula:
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