Understanding Standard Deviations: stdev.p vs stdev.s in Excel Explained

Understanding standard deviations in Excel can seem like a complex task, but it’s quite simple once you get the hang of it. Essentially, standard deviation is a measure of how spread out numbers are in a data set. In Excel, there are two types of standard deviation functions you can use: stdev.p and stdev.s. stdev.p is used when you’re working with an entire population, while stdev.s is used when you’re working with a sample of a population. Let’s dive in and learn how to calculate these in Excel.

Step by Step Tutorial: Calculating Standard Deviation in Excel

Before we get into the nitty-gritty of calculating standard deviation in Excel, it’s important to understand what we’re trying to achieve. In this tutorial, we’ll learn how to use both stdev.p and stdev.s functions and understand the difference between them.

Step 1: Enter your data

Insert your data into a single column in Excel.

Entering your data into Excel is the first step. Make sure to input your numbers in a single column to keep things organized.

Step 2: Choose the function

Select either stdev.p or stdev.s function based on whether your data represents a population or a sample.

Choosing the correct function is critical. stdev.p is used when your data represents the entire group you’re studying, while stdev.s is for when you only have a sample of the entire group.

Step 3: Apply the function

Enter the function formula, select your data range, and press enter to get the standard deviation.

Applying the function is straightforward. Just type =STDEV.P(range) or =STDEV.S(range), replacing "range" with your actual data range, and hit enter. Excel will do the math for you!

After completing the above steps, you’ll have the standard deviation of your data. This tells you how much your data varies and can be a valuable insight into your dataset’s consistency or variability.

Tips for Calculating Standard Deviation in Excel

  • Always double-check whether you should use stdev.p or stdev.s based on your data being a population or a sample.
  • Ensure your data is clean and organized before inputting it into Excel to avoid any errors.
  • Use parentheses to specify the range of your data when entering the function formula.
  • Remember that a high standard deviation indicates that data points are spread out over a large range of values.
  • If you’re unsure about your calculations, cross-verify the results with the manual calculation method or an online calculator.

Frequently Asked Questions

What is the difference between stdev.p and stdev.s?

Stdev.p is used for calculating the standard deviation of a population, while stdev.s is used for a sample of a population.

Can I use stdev.p for sample data?

It’s not recommended, as it would not give an accurate representation of your sample’s standard deviation.

How do I know if my data is a sample or a population?

If your data consists of every possible outcome or instance, then it’s a population. If it’s just a part of the total, it’s a sample.

What if my standard deviation is zero?

If your standard deviation is zero, it means all your data points are identical.

Can standard deviation ever be negative?

No, the standard deviation is always a positive number or zero because it’s a measure of spread or dispersion.


  1. Enter your data into a single column in Excel.
  2. Choose stdev.p for population data and stdev.s for sample data.
  3. Apply the appropriate function and press enter to get the standard deviation.


So there you have it, folks – a comprehensive guide to understanding and calculating standard deviations in Excel. Whether you’re a student, a researcher, or just someone trying to make sense of a bunch of numbers, knowing how to work with standard deviations can be incredibly handy. It tells you how much variation there is in your data, which can be pivotal in making informed decisions or conclusions.

Remember, stdev.p is your go-to when you’re looking at the whole group, while stdev.s is when you’re dealing with a portion of the group. Keep your data clean, choose the right function, and let Excel do the heavy lifting for you. And if you ever get stuck, just come back to this article for a quick refresher. Happy calculating!