How to Calculate Standard Deviation
This article explains how to calculate the standard deviation of a dataset in Excel. Standard deviation is a statistical measure that indicates the degree of variance or dispersion in a dataset. A higher standard deviation indicates greater data variability, while a lower standard deviation suggests that the data points are closer to the mean.
Using the STDEV.P Function to Calculate Population Standard Deviation
| A | B | C | D | |
|---|---|---|---|---|
| 1 | Dataset | |||
| 2 | 10 | |||
| 3 | 15 | |||
| 4 | 8 | |||
| 5 | 12 | |||
| 6 | 18 | |||
| 7 | =STDEV.P(A2:A6) |
Steps
- Enter the data in the range A2:A6.
- In an empty cell (e.g., A7), type the formula =STDEV.P(A2:A6).
- Press ENTER to calculate the population standard deviation.
Role of the STDEV.P Function
The STDEV.P function calculates the standard deviation for an entire population. A population includes all data points of interest. Use this function when the dataset represents the entire population.
Result
3.64 (the population standard deviation for the dataset 10, 15, 8, 12, 18).
Using the STDEV.S Function to Calculate Sample Standard Deviation
| A | B | C | D | |
|---|---|---|---|---|
| 1 | Dataset | |||
| 2 | 10 | |||
| 3 | 15 | |||
| 4 | 8 | |||
| 5 | 12 | |||
| 6 | 18 | |||
| 7 | =STDEV.S(A2:A6) |
Steps
- Enter the data in the range A2:A6.
- In an empty cell (e.g., A7), type the formula =STDEV.S(A2:A6).
- Press ENTER to calculate the sample standard deviation.
Role of the STDEV.S Function
The STDEV.S function calculates the standard deviation based on a sample. A sample is a subset of a population used to estimate the population standard deviation. Use this function when the dataset does not include the entire population.
Result
4.20 (the sample standard deviation for the dataset 10, 15, 8, 12, 18).
Summary
Standard deviation is a crucial measure of data dispersion. In Excel, you can calculate it using various functions: STDEV.P for the population standard deviation and STDEV.S for the sample standard deviation.