Statistical
Standard Deviation Analysis
Calculate the standard deviation to understand how spread out your data is from the average. Low SD means data is clustered near the mean; high SD means data is widely spread.
Excel Formula
=STDEV(A2:A100)Step-by-Step Explanation
1
STDEV calculates the standard deviation for a sample
2
A2:A100 is the data range
3
Use STDEV.S for sample data (most common)
4
Use STDEV.P for entire population data
5
Result is in the same units as your data
Example
| Dataset | Mean | Std Dev | Interpretation |
|---|---|---|---|
| Test Scores | 75 | 5.2 | Most scores between 70-80 |
| Sales ($) | $50K | $15K | Sales vary widely ($35K-$65K) |
Result: =STDEV(A2:A100) → 5.2 (for test scores)
Common Variations
Population SD
=STDEV.P(A2:A100)When data is the entire population
Coefficient of variation
=STDEV(A2:A100)/AVERAGE(A2:A100)*100SD as percentage of mean
Variance
=VAR(A2:A100)SD squared — another spread measure
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