How to Calculate Variance in Excel - Practical Guide

Learn to calculate variance in Excel using VAR.S (sample) and VAR.P (population) functions. Variance measures how spread out data points are from the average, essential for statistical analysis, quality control, and risk assessment in finance and research.

Why This Matters

Variance is critical for data analysis, investment risk assessment, and quality management decisions in professional settings.

Prerequisites

•Basic understanding of Excel data entry
•Familiarity with simple formulas and cell references

Step-by-Step Instructions

Organize your data

Enter your numerical dataset in a column (e.g., A1:A10) or row, ensuring all values are numeric and no empty cells are mixed within the range.

Click the target cell

Select the empty cell where you want the variance result to appear.

Enter the VAR.S formula

Type =VAR.S(A1:A10) for sample variance, which divides by n-1 and is used for data samples.

Or use VAR.P for population

Type =VAR.P(A1:A10) if analyzing an entire population, which divides by n instead of n-1.

Press Enter to calculate

Hit Enter to execute the formula and display the variance result.

Alternative Methods

Use legacy VAR function

Type =VAR(A1:A10) for backward compatibility with older Excel versions; it functions identically to VAR.S.

Use VARP for population variance

Type =VARP(A1:A10) as a legacy alternative to VAR.P, though VAR.P is preferred in modern Excel.

Tips & Tricks

✓Always use VAR.S for sample data and VAR.P only when you have the entire population.
✓Standard deviation is the square root of variance; use STDEV.S or STDEV.P for a related metric.

Pro Tips

★Use absolute references (e.g., =VAR.S($A$1:$A$10)) when copying variance formulas down to ensure the range doesn't shift.
★Combine variance with AVERAGE and other statistics in a dashboard using mixed cell references for dynamic analysis.

Troubleshooting

Formula returns #VALUE! error

Check your data range for text, spaces, or non-numeric values; remove or correct them and reenter the formula.

Variance result seems unexpectedly large or small

Verify you're using the correct formula (VAR.S vs VAR.P) and confirm your data has no outliers or errors.

Cannot find VAR.S function in older Excel

Use =VAR() instead, which is the legacy equivalent and available in Excel 2007 and earlier versions.

Related Excel Formulas

STDEV.S STDEV.P AVERAGE VARP VAR

Frequently Asked Questions

What's the difference between VAR.S and VAR.P?

VAR.S calculates sample variance (divides by n-1) and is used for data samples, while VAR.P calculates population variance (divides by n) for complete datasets. Use VAR.S unless you're certain you have the entire population.

Can I calculate variance of negative numbers?

Yes, variance works with negative numbers. The formula measures spread regardless of sign, so negative values are treated like positive ones in variance calculations.

How is variance related to standard deviation?

Standard deviation is the square root of variance; if variance is 16, standard deviation is 4. Standard deviation is easier to interpret because it's in the same units as your original data.